Tropical Journal of Pharmaceutical Research

Published by African Journals Online
Online ISSN: 1596-9827
Print ISSN: 1596-5996
Publications
Assay of reserpine in Brinerdin ® and Regroton ®
Assessment of accuracy and repeatability of the new method of assay of reserpine
Purpose: To develop a simple, rapid and improved colorimetric method for the assay of reserpine in tablets Method: The method is based on the aromatic ring coupling of reserpine with 4-carboxyl-2,6-dinitrobenzene diazonium ion with the consequent formation of an azo adduct. Optimization of reaction conditions and validation were carried out and the method applied to assay of reserpine in tablets. Result: Reserpine coupled readily with CDNBD and optimization of experimental conditions showed the reaction to be completed in 10 min at room temperature. A 1:1 drug to reagent stoichiometric ratio was obtained for the azo adduct formed. The adduct exhibited a bathochromic shift with respect to the drug and pronounced hyperchromic shift with respect to the reagent. Sample analyses were done using a colorimeter at 470 nm. The assays were linear and reproducible over the concentration range of 2.25 -24 µg/mL. The new method was successfully applied in the assay of reserpine in tablets with a performance similar to the official (USP) spectrophotometric method (p > 0.05). This method represents a profound improvement on the previously reported colorimetric method for reserpine. Conclusion: The method developed is rapid and could find application in in-process quality control of reserpine.
 
The effects of bee venom on NO production and iNOS protein expression in LPS stimulated Raw 264.7 cells. Note: Values represent means ± SEM of seven samples. Means with different superscripts (a, b, c) are significantly different (p < 0.05).
Purpose: Bee venom (BV) is traditionally used in many inflammatory chronic conditions but its mechanism of action at molecular level is not fully understood. This study was undertaken to elucidate the mechanism of action of bee venom at the molecular level Methods: We used lipopolysaccharide (LPS) stimulation in Raw 264.7 macrophage (RM) cells and studied the effect of BV on cell proliferation, inflammation related protein expression by western blotting and RNA expression by reverse transcriptase polymerase chain reaction (RT-PCR). Results: Bee venom was toxic to RM cells above10 µg/ml but reduced the production of nitric oxide (NO) at 2–10 µg/ml in LPS stimulated RM cells by inhibiting the expression of inducible nitric oxide synthase (iNOS) and cyclooxigenase (COX)-2 via nuclear factor (NF)-κB. However, bee venom also induced the pro-inflammatory cytokine, interleukin (IL)-1β via p38 mitogen activated protein kinase (MAPK) which is known to stimulate inflammatory activity. Conclusion: It seems that NFκB and p38 MAPK signal pathways are involved in triggering the functional activation of LPS-stimulated macrophage. We suggest that some components of bee venom can cause inflammation by inducing IL-1β via p38 MAPK while others act as anti-inflammatory by suppressing iNOS and COX2 via NFκB.
 
Absorption spectrum of mefenamic acid in ethyl acetate
Assay of mefenamic acid capsules by official method and the new method
Three-day assessment of accuracy and precision of the new method of assay of mefenamic acid
Purpose: To develop a novel colorimetric assay method for mefenamic acid capsules. Method: The new method (aromatic ring derivatization technique) is based on a diazo coupling reaction using diazotized 4-amino-3,5-dinitrobenzoic acid (ADBA) as a chromogenic derivatizing reagent. Result: Optimization studies showed that the coupling reaction is very fast and completed in less than 1 minute. A 1:1 drug to reagent stoichiometric ratio was obtained for the azo dye formed. The azo adduct formed exhibits bathochromic shift with absorption maximum (lmax) at 490 nm, which was selected as the analytical wavelength. Lower limit of quantitation of mefenamic acid was 1 mg/ml. The assays were linear over the concentration range of 1 - 6 mg/ml and reproducible. This new method has been successfully applied in the assay of mefenamic acid capsules with accuracy similar to the official (B.P) titrimetric method of assay (p>0.05) and has the advantages of speed, high sensitivity, lower limit of detection and can be automated. Conclusion: The method developed could find application in in-process quality control of mefenamic acid capsules. Keywords: Mefenamic acid assay, 4-amino-3,5-dinitrobenzoic acid, colorimetry, diazotization Trop J Pharm Res, June 2002; 1(1): 15-22
 
FTIR spectra of gliclazide alone (A), PEG 8000 alone (B), gliclazide-PEG 8000 PMs (C), and gliclazide-PEG 8000 SDs (D).
X-ray diffractograms of gliclazide alone (A), PEG 8000 alone (B), gliclazide-PEG 8000 PM (C), and gliclazide-PEG 8000 SD (D).
In vitro dissolution of gliclazide, as well as its physical mixtures and solid dispersions of gliclazide in pH 1.2 buffers
DSC thermograms of gliclazide alone (A), PEG 8000 alone (B), gliclazide-PEG 8000 PM (C), gliclazide-PEG 8000 SD (D).
Effect of PEG 8000 concentration and Gibbs free energy on the solubility of gliclazide
Purpose: The aim of the present study was to characterise gliclazide solid dispersions (SDs) prepared with polyethylene glycol (PEG) 8000 and compare them with SDs in PEG 6000. Methods: Gliclazide SDs containing varying concentrations of PEG 8000 were prepared using the fusion – solvent technique, and their phase solubility behavior and dissolution in 0.1N HCl were assessed at 37°C. The physical state of, and gliclazide-PEG interactions in, SDs and physical mixtures prepared in ratios of 1:1, 1:2 and 1:5 (gliclazide: PEG 8000), respectively, were characterized by x-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). Results: The solubility of gliclazide increased with increasing amount of PEG 8000 in aqueous medium. Gibbs free energy (ΔGo tr) values were all negative, indicating the spontaneous nature of gliclazide solubilisation. Dissolution studies indicated a significant increase in the dissolution of gliclazide when dispersed in PEG 8000. FTIR analysis demonstrated the absence of well-defined gliclazide - PEG 8000 chemical interaction while DSC and XRD studies indicated the amorphous /microcrystalline state of gliclazide in the SDs. Conclusion: In both solid dispersions and physical mixture, PEG 8000 increases the solubility and dissolution rate of gliclazide. The increased dissolution rate of gliclazide may be due to the formation of microcrystals, increased wettability and dispersibility in systems containing PEG 8000.
 
Dissolution profiles of pure GLZ(),GPM1(■), GPM2(), GK1(), GK2(), GCP1() and GCP2().  
Dissolution profiles of Kneaded complexes: 15min kneading at 25° ± 2.0° (), 30min kneading at 25° ± 2.0° (■), 45min kneading at 25° ± 2.0° (),15min kneading at 75 o C(----),30min kneading at 75 o C (----), 45min kneading at 75 o C(----)  
Purpose: Gliclazide has been found to form inclusion complexes with β- cyclodextrin (β-CD) in solution and in solid state. The present study was undertaken to determine a suitable method for scaling up gliclazide-β-CD inclusion complex formation and to evaluate the effect of some parameters on the efficiency of complexation. Method: The solid inclusion complexes of gliclazide and β-cyclodextrin were prepared at a molar ratio of 1:1 and 1:2 by mixing, kneading, and coprecipitation methods both on small and large scales. The effect of parameters such as kneading time and temperature on complexation was also studied. Characterization was performed using infrared spectroscopy, X-ray diffractometry, and dissolution studies. In vitro release studies were carried out in phosphate buffer (pH 6.8). Result: All the methods of preparation of complexes were found to be useful in increasing the solubility of gliclazide except mixing method where the rise in solubility was not significant. Both kneading and co-precipitation methods in 1:2 molar ratios were found to be equally effective in improving the solubility of gliclazide. The formation of inclusion complexes was evident in these formulations as shown by IR and XRD studies. But when carried out on a large scale, co-precipitation method was found to be more tedious and time-consuming than kneading method. Moreover percent recovery of complexes in the kneading method was found to be 98.76% as compared to 92.05% in case of co-precipitation method. Conclusion: Drug content studies, IR spectroscopic studies, X-Ray diffractometry studies and in vitro dissolution study data indicated that inclusion complexes prepared by kneading method in 1:2 molar ratios were suitable for improving the solubility of gliclazide. The same formulation was prepared at large scale and optimum formulation conditions were established.
 
Antimicrobial activity as MICs (µg ml -1 ) of flavonoids and the references against tested isolated strains of Klebsiella pneumoniae (Kpn: 1-10)
Purpose: In the present study, six flavonoids (5,7-dimethoxyflavanone-4'-O-β-D-glucopyranoside, 5,7dimethoxyflavanone-4'-O-[2''-O-(5'''-O-trans-cinnamoyl)-β-D-apiofuranosyl]-β-D-glucopyranoside, naringenin-7-O-β-D-glucopyranoside, 5,7,3'-trihydroxy-flavanone-4'-O-β-D-glucopyranoside, rutin, and nicotiflorin) isolated from Galium fissurense , Viscum album ssp. album and Cirsium hypoleucum were screened against extended-spectrum β-lactamase producing multidrug-resistant (trimetoprimesulphametoxazole, sulbactam-ampicillin, clavulonate-amoxicilin, ceftriaxon, cefepime, imipenem, ceftazidime, tobramicin, gentamicin, ofloxacin, ciprofloxacin) bacteria Klebsiella pneumoniae (ESβLs). Methods: We performed susceptibility testing according to the Clinical and Laboratory Standards Institute (CLSI, formerly NCCLS) and used an inhibition endpoint for determination of the minimum inhibition concentrations (MICs). Results: All the flavonoids showed in vitro antimicrobial activity against all the isolated strains of K. pneumoniae similar to the control antibacterial (ofloxacin) at the concentrations of 32 -64 µg ml-l; another control, ampicillin, had no activity. Since, ESβL-producing strains are known to be resistant to all β-lactam antibiotics, our results fall notably within the concentration range for antimicrobial activity. Conclusion: To the best of our knowledge, this is the first report of the study of the activity of these flavonoids against (ESβL)-producing K. pneumoniae and may throw light to the low-toxicity of flavonoids, and their potentials for developing therapies for infections caused by ESβL-producing bacteria in the future. Further work is under investigation to identify their precise antibacterial mechanism.
 
Purpose: To evaluate the microbial load on 17 randomly selected plant samples from 60 ethnobotanically collected medicinal plants from five local markets in Abeokuta, Ogun State, Nigeria. Method: The pour plate method was used to cultivate serially diluted portions of the medicinal plant samples investigated. Enumeration of bacteria was carried out on nutrient agar (NA) while that of fungi was effected on Sabouraud agar (SA). Results: The identified microbial isolates include 12 bacterial and 6 fungal genera. The mean heterotrophic bacteria counts of the different herbal samples ranged from 1.3 × 10 5 cfu/g ( Cnestis ferruginea ) to 6.7 × 10 6 cfu/g ( Daniellia oliveri ), while total fungal propagule counts ranged from 0.0 × 10 1 cfu/g ( Terminalia superba , Cola gigantea , Rauwolfia vomitoria , Zingiber officinale and Argemone mexicana ) to 7.1 × 10 6 cfu/g ( Nesogordonia papaverifera ). The synopsis and frequency (prevalence rate) of microbial species isolation showed that Bacillus spp. (82.4 %) and Mucor spp. (47.1 %) had the highest prevalence rates among bacteria and fungi, respectively. Conclusion: The findings from this study emphasized the need for constant quality assessment of herbal drugs on sale in order to ensure the production of therapeutic products suitable for human consumption.
 
Purpose: To assess the microbiological quality of some milk products in Abuja, Nigeria capital city; and the resistance of isolates to some broad spectrum antibiotics. Method: Three packs of different brands of yoghurt and pasteurized milk purchased from four different locations were assessed in duplicate. Isolates were identified using growth on agar and broth, Gram's reaction, colony morphology, biochemical tests results and criteria for disregarding negative cultures. Resistance of isolates from pasteurized milk was determined using the antibiotic sensitivity test (zones of inhibition). Results: 33 bacterial and 12 fungal isolates belonging to 9 and 3 genera respectively were identified from the yoghurt samples. Presence of yeast was found to increase the microbial load of bacterial groups and decrease the load of live and active cultures which was absent in 33% of yoghurt samples. 27% of samples were heat-treated and contained no LAC. A total of 19 bacterial isolates belonging to 6 genera were identified from the pasteurized milk samples. Milk quality based on methylene blue decolourization time measurement revealed that 49% of the assessed samples were of excellent quality, 37% of good quality, 14% of fair quality, and 0% of poor quality. No milk sample was sterile. Among the three antibiotics tested for resistance on the isolated bacterial strains, three different resistance patterns were observed. Conclusion: Our study shows that mesophilic yeast was the main cause of yoghurt spoilage. Sampled yoghurt is unlikely to make a vital input to LAC intake in Nigerian diets and poses some yet undefined risk. Visual inspection of packages, quality assessment of diary plants/vessels and packaging materials, dye reduction tests, refrigeration at all times, and resistance testing should be critically considered before the use of recommended antibiotics.
 
Effect of extracts of H. spinosa leaf on Brewer's yeast-induced pyrexia in rats
Purpose: Hygrophilaspinosa T. Anders (Acanthaceae) is commonly used in the traditional system of medicine for the treatment of inflammation, pain, jaundice, rheumatism, arthritis, anaemia, etc. In the present study, we investigated the anti-inflammatory and antipyretic activities of the petroleum ether, chloroform, alcoholic and aqueous extracts of the leaf of this plant. Methods: The anti-inflammatory activity of the various extracts was studied based on their effects on carrageenan-induced paw oedema in rats while antipyretic activity was evaluated on the basis of their effect on Brewer’s yeast-induced pyrexia in rats. The extracts were screened for alkaloids, steroids, proteins, flavonoids, saponins, mucilage, carbohydrates, organic acids, fats and oils. Results: Preliminary phytochemical screening revealed the presence of alkaloids, steroids, proteins, flavonoids, fats and oils, tannins, mucilage and organic acids in the leaves of H. spinosa. Chloroform and alcoholic extracts of leaves of H. spinosa produced significant (p < 0.05 and p < 0.01) anti-inflammatory and antipyretic activities in a dose-dependent manner. On the other hand, petroleum ether and aqueous extracts did not show significant anti-inflammatory and antipyretic activities. The maximum anti-inflammatory activities produced by chloroform and alcoholic extracts (400 mg/kg) were 33.7% and 47.5%, respectively. These two extracts also reduced elevated body temperature in rats at 200 and 400 mg/kg body weight doses throughout the observation period of 6 h. Conclusion: Chloroform and alcoholic extracts of H. spinosa leaves have anti-inflammatory and antipyretic activities.
 
Thermodynamic parameters of the EDA complexes
Benesi-Hildebrand plot of chloranilic acid-chloroquine complex. The inset shows the plot of log K versus 1/T for the interaction and its slope is calculated to be 0.9048
Purpose: The electron donor-acceptor interaction between drugs which act as electron donors and some electron-deficient compounds (π acceptors) has severally been utilized as an analytical tool for the quantitation and qualitative assessment of such drugs. The objective of this study, therefore, was to develop an assay procedure for dosage forms of chloroquine phosphate based on its reaction with chloranilic acid which resulted in the formation of a charge-transfer complex. Methods: The complex formation between chloroquine phosphate and chloranilc acid as evidenced by the instantaneous change in colour of a solution of chloranilic acid in dioxan from yellow to purple upon addition of a solution of chloroquine phosphate in chloroform was monitored spectrophotometrically to determine the wavelength of maximum absorption. The stoichiometry of the complex formed was evaluated using the Job’s continuous variation method while the thermodynamics of the complex was evaluated spectrophotometrically with the aid of the Benesi-Hildebrand plot. Results: Spectrophotometric absorption studies showed evidence of the formation of strongly bonded and highly stable charge-transfer complex between chloroquine phosphate and chloranilic acid in a 3:2 stoichiometry in non-aqueous medium. The transitions involved were detected at wavelengths longer than those of the individual pure substances in the visible region of the spectrum. Conformity with Beer’s law was evident over the concentration range 0.8 – 8.0 mg/100 ml of chloroquine phosphate; thus making it possible for an accurate quantitative determination of the drug. Conclusion: The studied complexation phenomenon formed a basis for the quantitative determination of both pure samples and individual dose units of chloroquine phosphate and is considered a simple, sensitive and precise analytical tool with high accuracy for routine analysis of chloroquine phosphate in developing countries where sophisticated analytical instruments may not be available.
 
FTIR spectrum of pure aceclofenac 
FTIR spectrum of aceclofenac tablets (F7) 
In vitro release profile of the prepared aceclofenac sustained release tablets in pH 1.2 and pH7.5 media
and 2 show the spectra of the pure drug and tablet formulation (F7), respectively. The spectrum for pure aceclofenac showed major peaks at the following wave numbers: 3319.39,1771.71,17I7.12,1589.69,1508.14,1 452.50,1418.56,1344.80,1256.64,1150.53, 1056.35, 899.33, 749.96, 668.15 and 625.98 cm
Purpose: The objective of the study was to develop matrix tablets for oral controlled release of aceclofenac using ethyl cellulose, guar gum and various grades of cellulose polymers. Methods: Possible drug-excipient interaction was evaluated by high performance liquid chromatography (HPLC) and Fourier infrared spectroscopy (FTIR). The tablets prepared were assessed for their physicochemical, in vitro drug release at pH1.2, 4.5, 6.8 and 7.5 and stability characteristics. Comparison with a ′once daily′ commercial aceclofenac product was made in the in vitro studies. Results: There was no interaction between aceclofenac and the polymers used as excipients. Furthermore, the physicochemical properties of the tablets were satisfactory. The release profile of one of the formulated aceclofenac tablets (F7), which contained hydroxypropyl methyl cellulose (HPMC K4M), was statistically similar (p < 0.05) to that of the commercial aceclofenac brand in all the dissolution media. The formulated products ware stable and showed no changes in physical appearance, drug content, or dissolution pattern after storage at 40 o C /75 %RH for 6 months. Conclusion: The results indicate that it is feasible to achieve a stable ′once daily′ sustained release aceclofenac tablet formulation by using HPMC K4M of 4000cps viscosity grade as matrix material.
 
Effect of extract of M. morindoides (MM-EA) on the intestinal transit of charcoal meal in rat
Effect of extract of M .morindoides (MM-EA) on castor-oil induced enteropooling in rat
Purpose: The objective of the study was to investigate the ethyl acetate extract of Morindamorindoides (Baker) Milne-Redh (Rubiaceae) (MM-EA) properties against experimental diarrheoa induced by castor oil in albino Wistar rats. Methods: The ethyl acetate extract of Morinda morindoides (250, 500, and 1000 mg/kg body weight) was administered orally to three groups of rats (five animals per group) in order to evaluate the activity of the extract against castor oil-induced diarrhea model in rat. Two other groups received normal saline (5mg/kg) and loperamide (5mg/kg) as positive control. The effect of the extract on intestinal transit and castor oil-induced intestinal fluid accumulation (enteropooling) was assessed. Results: At oral doses of 250, 500, and 1000 mg/kg body weight, the plant extract showed pronounced and dose-dependent antidiarrheal activity. The protective role of the extract at 1000 mg/kg was comparable to that of the reference drug, loperamide (5mg/kg). The extract (1000 mg/kg) produced a decrease in intestinal transit comparable to atropine (5mg/kg), and significantly (p<0.01) inhibited castor oil-induced enteropooling. No mortality and visible signs of general weakness were observed in the rats following the extract administration of up to a dose of 6000 mg/kg. Conclusion: The results showed that the extract of M. morindoides has a significant antidiarrheal activity which supports its use in traditional herbal medicine practice.
 
Purpose: The fruits of Limonia acidissima Linn are used traditionally in India for the treatment of tumours, asthma, wounds, cardiac debility and hepatitis. The purpose of the present study was to evaluate the wound healing activity of the methanol extract of its fruit pulp (MELA) in incision, excision and dead-space wound models. Methods: Albino rats of either sex were divided into four groups, viz, wounded control, wounded rats administered standard drug, nitrofurazone (2 %), and wounded rats administered MELA 200 and 400 mg/kg, respectively. In incision wound model, wound breaking strength and epithelization period were evaluated, while in excision wound model, wound contraction was studied. In dead-space wound model, granulation tissue dry weight, hydroxyproline levels in dry granulation tissue, as well as superoxide dismutase (SOD) and catalase levels in wet granulation tissue were estimated. Granulation tissue was subjected to histopathological examination in order to determine whether there was healing by formation of collagen in the wound tissue in extract-treated animals. Results: Increased wound breaking strength, decreased epithelization period, increased wound contraction, increased granulation tissue weight and hydroxyproline concentration were observed in the various groups, compared with the control group. Also, increased activity of anti-oxidant enzymes, i.e., higher SOD and catalase levels, were seen in extract-treated groups when compared to controls. Wound healing activity was statistically significant (p < 0.001) in animals treated with 400 mg/kg of the extract. Conclusion: The methanol extract of L. acidissima possesses significant dose-dependant wound healing and anti-oxidant activities; this supports traditional claims for the plant as a wound healer.
 
Effect of pH on L-asparaginase activity Figure 2: Effect of temperature on Lasparaginase activity  
Purification steps of isolated L-asparaginase
Lineweaver-Burk plot of isolated Lasparaginase  
Purpose: The objective of this investigation was to isolate marine actinomycetes, screen them for L-asparaginase activity and characterise the enzyme. Methods: Marine actinomycetes were isolated from sediment samples obtained from Tamilnadu and Kerala in India. The isolates were identified as actinomycetes by microscopical and biochemical tests. Production of L-asparaginase was carried out in three different media, namely, solid-state media, Tryptone Glucose Yeast extract (TGY) broth and Tryptone Fructose Yeast extract (TFY) broth.. The enzyme was purified to near homogeneity by ammonium sulphate precipitation, dialysis, gel filtration on Sephadex G-100 column and SDS-PAGE. Results: Among 10 marine isolates subjected to preliminary screening, only isolates S3, S4 and K8 showed potential for L-asparaginase activity. All three marine soil isolates synthesized asparaginase with yield ranging from 24.6 to 49.2 IU/ml. Soil isolate S3 showed the highest productivity of 49.2 IU/ml with a protein content of 65 µg/ml and optimum activity at pH 7.5 and 50 ºC. The apparent Km value for the substrate was 25 µM. Mg2+ ion slightly stimulated activity while Cu2+, Zn2+ and EDTA were inhibitory. Conclusion: The study revealed that marine actinomycetes may be a potential source of high yield, high substrate specificity L-asparaginase, which is an anti-leukaemia agent.
 
Characteristics of soil samples and number of actinomycetes isolated 
Sensitivity of various microorganisms to the soil isolates 
Purpose: To isolate and characterize antibiotic producing actinomycetes from soil samples in Belgaum, Karnataka, India. Methods: Crowded plate technique was used for the isolation of actinomycetes in media such as soybean - casein digest medium and actinomycetes isolation agar. The morphological and cultural characterization of one of the selected strains, designated A-4, was performed as per International Streptomycete Project (ISP). Results: Morphological and cultural studies showed that A-4 belonged to the Actinomycete genus. The morphological and cultural characteristics of the A-4 mutant showed cellular and aerial growth as well as soluble pigment formation in various ISP media. Conclusion: Findings from this investigation revealed that the selected strain, A-4, is an actinomycete.
 
Inhibition of DPPH by the ethanolic extracts of C. papaya, M. indica, P. Guajava and V. Amygdalina, respectively.
Purpose: Oxidative stress has been shown to play an important role in the development of anaemia in malaria. Indeed, increase in total antioxidant status has been shown to be important in recovery from malaria. The antioxidant activities of four medicinal plants traditionally used in the treatment of malaria in southwestern Nigeria were determined. Methods: The ethanolic extracts of the leaves of Carica papaya Linn. [Caricaceae] , stem bark of Magnifera indica Linn. [Anacardiaceae], leaves of Psidium guajava Linn. [Myrtaceae] and the leaves of Vernonia amygdalina Del. [Compositae], were used in the present study. The plant parts commonly used in the locality in malaria therapy were employed in this study. The plants were screened for the presence of phytochemicals and, their effect on 2,2-Diphenyl-1-picryl-hydrazyl radical (DPPH) was used to determine their free radical scavenging activity. Results: Phytochemical screening of the plants showed the presence of flavonoids, terpenoids, saponins, tannins and reducing sugars. M. indica did not contain cardiac glycosides and alkaloids while, P. guajava also showed the absence of alkaloids and anthraquinones. Anthraquinones was similarly absent from V. amygdalina. Concentrations of the plant extracts required for 50% inhibition of DPPH radical scavenging effect (IC50) were recorded as 0.04 mg/ml, 0.313 mg/ml, 0.58 mg/ml, 2.30 mg/ml and 0.054 mg/ml for P. guajava, M. Indica, C. papaya, V. amygdalina and Vitamin C, respectively. Conclusion: All the plants showed potent inhibition of DPPH radical scavenging activity, P. guajava being the most potent. The free radical scavenging (antioxidant) activities of these plants probably contribute to the effectiveness of the above plants in malaria therapy.
 
Purpose: To evaluate the ethanol extracts of the flowers, leaves, and stems of Centaureatchihatcheffii Fischer & C.A. Meyer (Asteraceae) for their anti-inflammatory and analgesic activities in male Swiss albino mice. Methods: For the evaluation of anti-inflammatory activity, hind paw oedema was induced in the mice with carrageenan and prostaglandin-E2 (PGE2) and the mice received either 100 and 200 mg/kg body weight doses of the flower extract or 200 mg/kg body weight dose of the leaf and stem extracts. Furthermore, ear oedema was induced in other groups of mice with 12-O-tetradecanoyl-13-acetate (TPA) and then administered with 0.5 mg/ear dose of the extract of either of the three plant parts. In order to evaluate analgesic activity, p-benzoquinone-induced abdominal constriction test was used with 100, 200 and 400 mg/kg body weight doses of the flower or 200mg/kg body weight dose of the leaf and stem extracts administered. Indomethacin and acetylsalicylic acid were the reference drugs for antiinflamatory and analgesic evaluations, respectively. Phytochemical screening of the flower extract was carried out by thin layer chromatography (TLC). Results: The results of evaluation of the anti-inflammatory activities induced by carrageenan and PGE2 showed that the flower extract diminished cyclo-oxygenase activitiy at the 200 mg/kg dose to the same level as the reference drug, indomethacin. However, no anti-inflamatory activity was seen in the TPAinduced ear oedema model. The extracts from all three parts of the plant showed analgesia in pbenzoquinone-induced abdominal constriction test. TLC analysis of the flower extract indicated the presence of sesquiterpen lactones, which may have been responsible for the analgesic activity. Conclusion: Our results support the use of C. tchihatcheffii in traditional medicine in Turkey for their anti-inflammatory and analgesic properties.
 
Purpose: A 1: 1: 2 mixture of exudates of Anchomonas difformis, Cyrtrospherma senegalense and Pycanthus angolensis is claimed to be used for the treatment of corneal ulcers. The purpose of the study is to evaluate the phytochemical constituents, antibacterial activities and the effectiveness of a mixture of these exudates in the treatment of corneal ulcers as claimed in Traditional medicine practice. Method: Fresh exudates were collected in different containers. They were reduced to dryness and each residue tested for phytochemical constituents. Exudates of P. angolensis was further tested for antimicrobial activities and its effect on chemical – induced corneal ulcers in rabbits. Result: Only reducing sugars were detected in exudates of A. angolensis and C. senegalensis. Bioactive constituents detected in exudates of P. angolensis were the reducing sugars and phenolic compounds- tannins and flavonoids. This also showed antimicrobial activity against the organisms used. It healed the NaOH – induced corneal ulcers in rabbits within ten of days of treatment. Conclusion: Exudates of P.angolensis contained bioactive constituents and exhibited antibacterial activity, and healed the corneal ulcers induced in rabbits. Its use in traditional practice for healing corneal ulcers is rational, even in the absence of exudates of A. angolensis and C. senegalensis.
 
The leaf, stem and flower of C. officinalis
Calendula officinalis Linn. (Asteraceae) is used medicinally in Europe, China and India amongst several places in the world. It is also known as "African marigold" and has been a subject of several chemical and pharmacological studies. It is used in traditional medicine, especially for wound healing, jaundice, blood purification, and as an antispasmodic. Chemical studies have underlined the presence of various classes of compounds, the main being triterpenoids, flavonoids, coumarines, quinones, volatile oil, carotenoids and amino acids. The extract of this plant as well as pure compounds isolated from it, have been demonstrated to possess multiple pharmacological activities such as anti-HIV, cytotoxic, antiinflammatory, hepatoprotective, spasmolytic and spasmogenic, amongst others. In this review, we have explored the phytochemistry and pharmacological activities of C. officinalis in order to collate existing information on this plant as well as highlight its multi-activity properties as a medicinal agent. This is as a result of the worldwide cultivation of the plant and increasing published reports on it.
 
Inhibition (%) of lipid peroxidation by different concentrations of methanol extract of H. nepalense, Ethyl acetate fraction (FA) and Vitamin E (Vit E).
DPPH scavenging activity of H.nepalense. 10mg/ml (□), 7.5mg/ml (▲), 5mg/ml (■) and 2.5 mg/ml (∆).
Purpose: The aim of the present study was to investigate antioxidant and antimicrobial effects of the methanol extract of Heracleum nepalense D.Don roots. Method: The antimicrobial effect was determined by agar dilution and disc diffusion method. The free radical scavenging potential was studied by using different antioxidants models of screening using vitamin E (5mM) as standard. Results: The crude methanol extract of H.nepalense root was found to be active against both Gram-positive and Gram-negative organisms. The ethyl acetate soluble fraction of the extract showed similar activity against these organisms. Similarly, the methanol extract at 1000 mg. ml-1 and the ethyl acetate fraction at 50 mg. ml-1 exhibited significant antioxidant activity in ferrous sulphate induced lipid peroxidation, 1,1- diphenyl- 2-picryl hydrazyl (DPPH), Hydroxyl radical and Superoxide scavenging models. Conclusions: The study confirms the possible antioxidant and antimicrobial potentiality of the plant extract. Presence of flavonoid alone or in combination with its other components could be responsible for the activity.
 
MTT assay result showing plot of cell viability versus extract dilution for acetone extract: 1:8 dilution of the acetone extract of Stevia rebaudiana leaves is effective drug concentration (non-toxic to Vero cells but cytotoxic to more than 50% of HEp2 cells).-Vero cells-HEp2 cells 
Purpose: The purpose of the study is to evaluate the antimicrobial and antitumor activities of Stevia rebaudiana (Asteraceae) leaf extracts. Methods: Four solvent extracts (ethyl acetate, acetone, chloroform and water) of Stevia rebaudiana leaves were investigated against Staphylococcus aureus , Salmonella typhi , Escherichia coli , Bacillus subtilis , Aeromonas hydrophila and Vibrio cholerae by using agar well diffusion method. Candida albicans , Cryptococcus neoformans , Trichophyton mentagrophytes and Epidermophyton species were used to test anti-yeast and antifungal activity. The cytotoxic effects of the extracts on Vero and HEp2 cells were assayed using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide [MTT]. Results: Among the four extracts tested, acetone extract had effective antibacterial potential, followed by ethyl acetate extract. The acetone extract showed greater activity against Gram-positive than against Gram-negative organisms. All the extracts were active against Epidermophyton species and Candida albicans . The 1:8 dilution of the acetone extract was non-toxic to normal cells and also had both anticancer and anti-proliferative activities against cancerous cells. Conclusion: The study confirms the antimicrobial and antitumor activities of Stevia rebaudiana leaves extracted using various solvents, and is therefore, a potential drug that requires further studies and development.
 
Characterization data of compounds 1a-f and 2a-f 
Purpose: Microbial infections often produce pain and inflammation. Chemotherapeutic, analgesic and anti-inflammatory drugs are prescribed simultaneously in normal practice. The compound possessing all three activities is not common.The purpose of the present study was to examine whether molecular modification might result in detection of new potential antirheumatic drugs having antimicrobial activities. Method: A series of novel 4-(5′-substituted aryl-4′, 5′-dihydropyrazole-3′-yl-amino) phenols 2a-f have been synthesized by treating substituted aryl-N-chalconyl amino phenols 1a-f with hydrazine hydrate. The starting materials were synthesized from p-aminoacetophenone. Their structures were confirmed by IR, 1H NMR spectral data. The synthesized compounds were investigated for analgesic, ant-inflammatory and antimicrobial activities. Result: The data reported in Tables 2, 3 & 4 shows that effect of variation in chemical structure on activity was rather unpredictable. Seldom did a particular structural modification lead to uniform alteration in activity in all tests. The substitution which appeared to be most important for high order of activity in the greatest number of test was the p-choloroaryl group. The introduction of p-nitro and p-hydroxy group in aryl moiety of the pyrazole analogs 2c and 2e produce compounds with potent analgesic, anti-inflamatory and, in a few cases, antimicrobial properties. Conclusion: The observed increase in analgesic, anti-inflammatory and antimicrobial activities are attributed to the presence of 4-NO2, 2-OH and 4-Cl in phenyl ring at 5-position of pyrazoline ring of synthesized compounds. In some cases their activities are equal or more potent than the standard drugs.
 
Structure of taraxerone (Dfriedoolean-14-en, 3 one)
Anti-tumour data for taraxerone
Structure of taraxerone (D- friedoolean-14-en, 3 one)  
As the dose of the drug increased, the proportion of cells lysed rose from 38 to 87%.
Purpose: Dregeavolubilis Benth , commonly known as Jukti in Bengal, is used in the treatment of boils and abscesses from ancient times. The purpose of this study is to elucidate the active compounds and as well as their anti-leishmanial and anti-tumour activities. Methods: Dried and crushed fruits of Dregea volubilis were extracted by petroleum ether (40 -60°C); the best solvent system had first been verified by analytical Thin Layer Chromatography (TLC). The extract was subjected to TLC and column chromatography (CC) to isolate the pure compounds. Spectra data were obtained by Infra Red pectroscopy, Mass Spectroscopy and Nuclear Magnetic Resonance -Proton Magnetic Resonance (PMR), Carbon Magnetic Resonance (CMR) and Distortionless Enhancement by Polarization Transfer (DEPT) -for structure elucidation of the isolated compound(s). One of the compounds isolated was screened for anti-leishmanial activity against promastigotes of Leishmania donovani and anti-tumour activity on K562 leukemic cell line. Results: A pentacyclic triterpenoid compound was isolated and designated as taraxerone, and then characterized as d-friedoolean-14-en, 3 one together with ß-sitosterol and a long chain lipid fraction.. This compound showed in vitro anti-leishmanial activity against promastigotes of Leishmania donovani (strain AG 83) and anti-tumour activity on K562 leukemic cell line. Conclusion: A pentacyclic triterpenoid compound designated as taraxerone and characterized as Dfriedoolean-14-en, 3 one together was successfully isolated. The structure was determined on the basis of spectral analysis (IR, MASS, NMR (PMR, CMR and DEPT) and the compound demonstrated in vitro anti-leishmanial and anti-tumour activities.
 
Minimum inhibitory concentrations (MICs) of the ethanol total extract of the aerial parts of Sida acuta against test organisms.
Purpose: The antimicrobial activity of the 90 % ethanol extract of the aerial parts of Sida acuta Burm. F. (Malvaceae) was investigated in other to verify its claimed ethno medicinal use in the treatment of microbial infections. Method: The antimicrobial activity of the extract was tested against standard strains and clinical isolates of some aerobic bacteria and a fungus using the Agar well diffusion method. Commercial antibiotics were used as positive reference standards to determine the sensitivity of the strains. Results: The extracts showed significant inhibitory activity against standard strains and clinical isolates of Staphylococcus aureus, clinical isolates of Bacillus subtilis and Streptococcus faecalis. The MIC values obtained using the Agar-dilution test ranged from 5.0 mg/ml. – 10.0 mg/ml. Neither the concentrated extract nor its dilutions inhibited Esherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa and Candida albicans Conclusion: The results demonstrate that the crude extract of the aerial parts of Sida acuta has a narrow spectrum of activity and suggest that it may be useful in the treatment of infections caused by Gram positive aerobic bacteria.
 
Frequency of occurrence of co-morbidities in hypertensive patients
The profiles of patient's age, weight, and systolic and diastolic blood pressure
Number of antihypertensive drugs prescribed with respect to the severity of hypertension
The frequency of use of the different classes of antihypertensive medications and its occurrence in the various drug combinations for treatment of high BP
Purpose: The role of physicians in the overall management of hypertension and their adherence to the JNC VII, WHO/ISH and ESH guidelines were examined in this study. Method: Case notes of hypertensive patients diagnosed between 1 January 2004 and 30 September 2005, in the Cardiology Clinic of University of Benin Teaching Hospital were retrieved for evaluation. They were assessed for adherence to the JNC VII, WHO/ISH and ESH guidelines, in the management of hypertension. Result: Five hundred and one case notes were used in the study. Prevalence of hypertension was highest in the Grade 2 category (36%). More women (60%) than men (40%) were affected, with a diagnostic mean systolic blood pressure (SBP); male (164.0mmHg ± 21.9), female (163.7 mmHg ± 18.8) and mean diastolic blood pressure (DBP); male (100.1 mmHg ± 13.2), female (97.3 mmHg ± 13.1). After commencing treatment, mean SBP and DBP for male and female were (131.8 mmHg ± 11.6; 84.3 mmHg ± 7.5), and (132.3 mmHg ± 11.5 83.2 mmHg ± 7.6), respectively. The commonest co-morbidity was diabetes mellitus (18%). Co-morbidity was commonest in Grade 2 (34%) and Grade 3 hypertension (34%). Almost half of the subjects (49%) were on a two-drug combination while 14% were on monotherapy. Calcium channel blockers were the most commonly prescribed anti-hypertensive drug (31%) followed by diuretics (30%). In combination drug regimen, diuretics were the commonest (74%). There was no evidence of body weight management in hypertension. Conclusion: Physicians in this hospital fairly complied with the stated guidelines, but do not appear to have recommended lifestyle modifications to their hypertensive patients.
 
Purpose: The root and aerial parts of Boerhaavia diffusa Linn. (Nyctaginaceae) were used in Ayurveda for the treatment of diabetes. The present study is aimed at evaluating the antidiabetic activity of chloroform extract of Boerhaavia diffusa leaves on chronic administration in streptozotocin-induced non-insulin-dependent diabetes mellitus (NIDDM) model diabetic rats. Methods: The blood glucose lowering activity of the leaf extract was studied in streptozotocininduced (65 mg/kg, i.v.) NIDDM model diabetic rats after oral administration of the extract at daily doses of 50, 100 and 200 mg/kg body weight for four weeks and compared with glibenclamide. Blood samples were collected from the tail vein before and also at weekly intervals for four weeks from the first dose of drug administration and blood glucose was analyzed by glucose-oxidase method using a visible spectrophotometer. Results: The leaf extract of B. diffusa produced dose-dependent reduction in blood glucose in streptozotocin-induced NIDDM rats comparable to that of glibenclamide. The results indicate that the reduction in blood glucose produced by the extract is probably through rejuvenation of pancreatic β-cells or through extrapancreatic action. Conclusion: The chloroform extract of Boerhaavia diffusa has significant antidiabetic activity and this supports the traditional usage of the plant by Ayurvedic physicians for the control of diabetes.
 
Purpose: This study assessed some microstructural effects of quinine, commonly used in malaria chemotherapy, especially in chloroquine-resistant and cerebral malaria, on the Nissl substance in the cerebellar cortex of adult Wistar rats using microanatomical studies. Methods: Twenty seven adult male Wistar rats, weighing between 150g and 190g, were randomly separated into groups A, B and C (n=9). The rats in group A served as the control and received intramuscular injection of physiological saline. Group B rats were injected intramuscularly with liquid quinine, 16mg/kg body weight as a start dose, followed by 8mg/kg body weight 8 hourly for seven days. Group C rats received the same treatment as group B but were subjected to a withdrawal period of one week. Groups A and B rats were sacrificed at the end of the treatment while group C rats were sacrificed at the end of one week. The cerebellum of each rat was removed and fixed in 10% formol saline for histological analysis. Results: The findings showed that the Nissl substances in the cerebellar cortex in control rats stained more intensely and distinctly compared with the less intense stain and degenerated Nissl substances in the treated rats. Conclusion: The observed degenerative changes in the Nissl substances in the cerebellar cortex of the treated rats may affect the synthesis of proteins in correlation with neuronal functions.
 
Swelling profiles of the microspheres in SGF
Release kinetic parameters of cefuroxime sodium from the microspheres in SIF
Purpose: Swellable microspheres based on polymers or their admixtures are frequently employed as drug delivery systems to achieve a controlled release and site-specific targeting of the incorporated drug. The objective of the present study was to enhance the rectal delivery of cefuroxime sodium by entrapping it into water-swellable gelatin-mucin microspheres. Method: Cefuroxime sodium-loaded microspheres containing admixtures of gelatin and porcine mucin were prepared via an emulsification-crosslinking technique. The drug entrapment efficiency of the microspheres was evaluated in citrate/phosphate buffer (pH 7.4) while the swelling properties was evaluated in both simulated gastric fluid (SGF) without pepsin and simulated intestinal fluid (SIF) without pancreatin (pH 1.2). Release of cefuroxime sodium from the microspheres was evaluated in vitro in SIF and further evaluated in vivo after rectal administration to male Wistar rats. Result: Results obtained showed that a high entrapment efficiency, most notably manifested in microspheres formulated with equal portions of gelatin and mucin, led to a high release (up to 85 %) and also a high bioavailability of the incorporated drug. Formulations based on varying portions of gelatin and mucin also showed high drug loading efficiency which also resulted in high drug release in SIF within 3 h. Drug release from the different formulations was observed to be rapid and generally showed a biphasic pattern. The mean AUC was shown to be formulation-dependent with values of 168±1.93μg.h/ml for the control, 262±3.47 μg.h/ml for microspheres based on gelatine only and 328±2.55 μg.h/ml for microspheres formulated with equal parts of gelatin and mucin. Conclusion: The inclusion of S-mucin in the composition of the microspheres has an enhancer effect on the release and rectal bioavailability of cefuroxime sodium which may be exploited in the design of a rectal delivery system of the drug.
 
Purpose: Drug overdose and poisoning are common clinical problems and could occur with the fluoroquinolones –a new series of synthetic antimicrobial agents. It therefore becomes important to study the adsorption of the fluoroquinolones on pharmaceutical adsorbents which could serve as possible antidotes for the emergency treatment of fluoroquinolone overdose or poisoning when they occur. Method: The rate and extent of adsorption of the fluoroquinolones on some pharmaceutical adsorbents, namely activated charcoal, kaolin and bentonite were investigated spectrophotometrically Results: The fluoroquinolones adsorbed on activated charcoal rapidly and attained equilibrium within fifteen minutes. The fluoroquinolones however adsorbed on kaolin and bentonite less rapidly and attained equilibrium within two hours. Activated charcoal and bentonite had high adsorption capacities for the fluoroquinolones while kaolin had low adsorption capacities for them. Conclusion: Because of the rapid rate of adsorption and high binding capacities exhibited by activated charcoal for the fluoroquinolones, it could be an effective antidote for the fluoroquinolones in cases of overdose or poisoning. Activated charcoal has shown a superior behaviour to both bentonite and kaolin in the adsorption of the fluoroquinolones.
 
Effect of exposure of pure drugs (chloroquine & chlorpheniramine) to 0% and 1% kaolin
Purpose: Kaolin is a known adsorbent, has lubricant property in powders and is therefore proposed as a lubricant in tablet formulations. This study was carried out to evaluate whether kaolin can adsorb some active drugs when mixed with them in tablet formulations even at very low concentrations. Method: Chloroquine and chlorpheniramine tablets were formulated with powder mixtures containing various concentrations of kaolin. The effect of kaolin on the physical properties of the tablets were examined and compared with those of standard lubricants like magnesium stearate and talc. Chloroquine and chlorpheniramine tablets and powders of amoxicillin/clavulanic acid oral powder and ampicillin/cloxacillin injection were also mixed with and without various concentrations of kaolin in water. Chemical assay of the drugs in the solutions were determined over time. Results: Kaolin significantly reduced the amount of each of the drugs in the solutions containing kaolin. Conclusion: Kaolin reduces the amount of some drugs when incorporated in drug formulations. Therefore, its inclusion in such drug formulations should not be encouraged.
 
Purpose: To evaluate the pharmacokinetics of nifedipine in healthy adult Pakistani subjects. Methods: Each of six fasting volunteers received 20 mg nifedipine (2 x Adalat® 10 mg capsules) orally once and then another one week later. Their blood samples were obtained at regular time intervals and analysed by HPLC. Using the non-compartmental approach, plasma levels of nifedipine were employed to compute their individual disposition kinetics, including Cmax (maximum plasma concentration), Tmax (time to reach maximum plasma concentration), MRT (mean residence time), AUC0-∞ (area under curve), AUMC0-∞ (area under first moment curve) and Ka (absorption rate constant). Results: The suggested therapeutic level of nifedipine for the treatment of hypertension (15-35 ng.mL-1) was achieved in all six volunteers within 0.25 h after dose administration, and maintained for more than 6 h. Tmax was 1.58 h and Cmax varied from 140 – 300 ng.mL-1. Mean absorption rate constant was 2.22 h-1 while mean absorption half-life was 0.43 h. The mean elimination rate constant was 0.16 h-1 while 5.7 h was recorded for terminal half-life. AUC0-∞, AUMC0-∞ and MRT were 1879.86 ng.h.mL-1, 8244.04 ng.h2.mL-1 and 4.2 h, respectively. Conclusion: This study confirms the rapid absorption of nifedipine in humans. AUC was similar to that previously reported for Nigerians but slightly lower than that stated in the literature for other south Asian races. Further studies on large segments of the local population using the non-compartmental model for kinetic analysis is recommended.
 
Amelioration of the increase in serum urea by vitamin B-complex injection.  
Body weight, and serum urea and creatine values of albino rats
Amelioration of increase in serum creatine by intramuscular vitamin B-complex  
Purpose: To evaluate the effect of vitamin B-complex on the nephrotoxicity of gentamicin in an established rat model. Methods: Adult Swiss albino rats weighing 170±20g were divided into 4 groups of 4 rats each. Each group was given one of the following: placebo injection (Control), 80mg/kg of gentamicin sulphate alone or with 1.5ml/kg/3ml/kg body weight of vitamin B-complex (intramuscular) containing 10mg thiamine, 1.5mg riboflavin and 1.0mg pyridoxal-6-phosphate per ml. Results: In the Swiss albino rats, daily intramuscular 80mg/kg gentamicin sulphate significantly (p<0.05) and consistently produced biochemical signs of nephrotoxicity after 5 days. Also, 1.5 ml/kg of B-complex significantly (p<0.05) ameliorated the rate and extent of increase in serum urea and creatine while 3ml/kg of the same drug completely prevented the increase in serum urea and creatine in this model. Conclusion: Vitamin B-complex dose-dependently ameliorated gentamicin-induced nephrotoxicity in adult Swiss albino rats when given intramuscularly. This finding may have important clinical utility.
 
Composition of different batches of mouth-dissolving tablets of famotidine
Purpose: The purpose of the present research was to the effect of camphor as a subliming agent on the mouth dissolving property of famotidine tablets. Method: Orodispersible tablets of famotidine were prepared using camphor as subliming agent and sodium starch glycollate together with crosscarmellose sodium as superdisintegrants. The formulations were evaluated for weight variation, hardness, friability, drug content, wetting time, in vitro and in-vivo dispersion, mouth feel and in vitro dissolution. Result: All the formulations showed low weight variation with dispersion time less than 30 seconds and rapid in vitro dissolution. The results revealed that the tablets containing subliming agent had a good dissolution profile. The drug content of all the formulations was within the acceptable limits of the United States Pharmacopoeia XXVII. The optimized formulation showed good release profile with maximum drug being released at all time intervals. Conclusion: This work helped in understanding the effect of formulation processing variables especially the subliming agent on the drug release profile. The present study demonstrated potentials for rapid absorption, improved bioavailability, effective therapy and patient compliance.
 
Effect of variables on blood glucose levels of animals (n=4)
Hypoglycemic effect of the oral hypoglycemic agents in diabetic rats (n=4)
Effect of coadministration of extract of Carica papaya extract on hypoglycemic effect of glimepiride (n=4) for 7 days duration.
Purpose: To investigate the interacting effects of co-administration of Carica papaya leaf extract on the hypoglycemic activity of metformin and glimepiride in an animal model. Method: Experimental factorial design was used to evaluate the individual and interaction influence of three variables ie nature (N), dose administered (C) and duration of administration (D), in a 23(=8) employed at two levels - ‘'high'' and ‘‘low'' - on blood glucose of diabetic rats on administration of ethanolic leaf extract of Carica papaya and two hypoglycemic agents, metformin and glimepiride. Unpaired t-test was used to test for significant difference due to administration of the combination Results: Extract of Carica papaya at 5.0 mg/kg produced significant blood glucose reduction with no significant reduction at the higher dose of 10 mg/kg (p>0.05). Changing nature from “low” (Carica papaya extract) to “high” (glimepiride or metformin) did not significantly change hypoglycemic activity. Generally, the ranking of the interacting effects was ND>CD>>NC for glimepiride/extract, and CD>ND>NC for metformin/extract. Administration of higher dose of the extract led to significant (p<0.01) increase in onset of activity of glimepiride. The onset of activity of metformin was not affected, but a significant lowering (p<0.05) of blood glucose was observed at 24 hr with all combinations of extract and metformin. Conclusion: Leaf extract of Carica papaya significantly delays the onset of hypoglycaemic activity of glimepiride, and increases the hypoglycaemic effect of metformin with the variables interacting differently for each drug-extract combinations. .
 
Purpose: To study the effect of different polymers on the solubility and dissolution rate of cefuroxime axetil (CFU) prepared by emulsion solvent diffusion (ESD) technique. Methods: The ESD technique employed involved three test solvents: first, substance dissolution medium-good solvent (acetone); second, partial dissolution medium for the substance-bridging liquid (dichloromethane), and third, immiscible with the substance-poor solvent (distilled water). The pure CFU and the prepared agglomerates were characterized in terms of production yield, drug content, solubility, in vitro release profile, flowability, density, wettability, as well as by thin layer chromatography (TLC), differential scanning calorimetry (DSC), x-ray diffraction (XRD),Fourier transforms infra red spectroscopy (FTIR) and stability test. Results: DSC showed a decrease in the melting enthalpy indicating disorder in the crystalline content. XRD also indicated changes in crystallinity, FTIR revealed that there were no chemical changes in the recrystallized agglomerates while dissolution data demonstrated a marked increase in the dissolution rate (>55 % in 45 min) compared with the pure drug (35% in 45 min). The improvement in the dissolution rate of CFU from optimized crystal formulation was attributed to the wetting effect of the polymers, change in drug crystallinity, altered surface morphology and micronization. The recrystallized agglomerates also exhibited higher wettability and flowability. Conclusion: The optimised recrystallized agglomerates exhibited good solubility, wettability, dissolution rate and other physicochemical properties compared to the unmodified CFU.
 
Effect of pre-treatment with Ziziphus mauritiana aqueous leaf extract on body weight changes in chronic alcohol fed rats (g/week)
Effect of Pre-treatment with Ziziphus mauritiana aqueous leaf extract on serum markers of tissue damage in chronic alcohol fed rats
Effect of Ziziphus mauritiana aqueous leaf extract on liver total antioxidant status, reduced glutathione and lipid peroxidation
Purpose: The effect of the aqueous extract of Ziziphus mauritiana leaf on hepatic lipid peroxidation, reduced glutathione and total antioxidant status was studied in chronic alcohol-induced liver damage. Method: Alcohol-induced liver toxicity was created by oral administration of 40% alcohol solution (v/v, 1ml/100g) to rats for 6 weeks. Other groups of rats were pretreated with 200 and 400 mg/kg bw aqueous extracts of Ziziphus mauritiana leaf or 100 mg/kg bw silymarin (reference drug) 30 min prior to alcohol ingestion. Body weight of rats was monitored weekly. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin and liver total antioxidant status, reduced glutathione and lipid peroxidation were evaluated. Result: Rats that received alcohol only showed significantly (p<0.05) elevated levels of ALT, AST, bilirubin, and hepatic lipid peroxidation while reduced glutathione, total antioxidant status and body weight significantly (p<0.05) decreased compared to control rats. Pretreatment of rats with aqueous extract of Ziziphus mauritiana 30 min prior to alcohol administration resulted in significant (p<0.05) depression of ALT, AST, bilirubin and lipid peroxidation levels compared to the group exposed to alcohol only. Administration of Ziziphus mauritiana extract prior to alcohol ingestion significantly (p<0.05) resulted in increased levels of reduced glutathione and total antioxidant status compared to the group that received alcohol only. Conclusion: The results of this study indicate that the aqueous extract of Ziziphus mauritiana leaf may prevent chronic alcohol-induced liver injury by enhancing the levels of total antioxidant status and inhibiting hepatic lipid peroxidation.
 
Purpose: To investigate the activity of Feronia elephantum fruit pulp extract (which is used in folk medicine) against indomethacin-induced gastric ulcer in rats. Methods: The fruit pulp was extracted with ethanol and the anti-ulcer activity of the extract in indomethacin-induced gastric ulceration in Swiss albino rats was evaluated. The parameters assessed were pH and acid concentration of gastric contents, and gastric ulcer index. Ranitidine was used as the reference anti-ulcer drug. Acute toxicity studies were also carried out. Results: The extract (500 mg/kg, p.o.) inhibited indomethacin-induced gastric ulceration by decreasing acid concentration of gastric fluid while elevating its pH (p < 0.01), and compared well with the standard drug, ranitidine (p < 0.001). However, its anti-ulcer activity was not as potent as that of ranitidine. Acute toxicity studies showed that there was no mortality following the administration of the extract in a dose range of 250 - 5000 mg/kg, p.o.. Conclusion: Feronia elephantum fruit pulp extract has potent antiulcer activity with low toxicity. Its anti-ulcer property probably acts via a reduction in gastric acid secretion. The results obtained support the use of this herbal material in folk medicine.
 
Purpose: The aim of this work was to formulate sodium alginate nanospheres of amphotericin B by controlled gellification method and to evaluate the role of the nanospheres as a “passive carrier” in targeted antifungal therapy. Methods: Sodium alginate nanospheres of amphotericin B were prepared by controlled gellification method, and the particle size analysis was carried out by scanning electron microscopy. The carrier capacity of sodium alginate was evaluated in terms of drug to polymer ratio. In vitro release study was carried out on all drug loaded nanospheres by the dialysis method. Release kinetics of drug from different drug loaded nanospheres was also determined. The in vivo antifungal efficacy of nanospheres bound drug vis-à-vis the free drug was evaluated in candidiasis- induced mice models. Results: Preparation of nanospheres through controlled gellification method yielded particles with a size range of 419.6 ± 0.28 nm. Studies on drug to polymer ratio showed a linear relationship between concentration of drug and drug loading capacity. In vitro release kinetic study revealed that the release of drug from the nanospheres followed Fickian diffusion. In vivo studies showed that the nanosphere-bound drug produced a higher antifungal efficacy than the free drug. Conclusion: The formulated sodium alginate nanospheres containing amphotericin B was found to have better antifungal activity when compared to the free drug and also yielded sustained in vitro release.
 
Purpose: The aim of this work was to prepare nimodipine-loaded alginate-chitosan beads for sustained drug release. Methods: Nimodipine-loaded alginate-chitosan beads were prepared by ionic gelation method using various combinations of chitosan and Ca2+ as cations and alginate as anion. The swelling ability and in vitro drug release characteristics of the beads were studied at pH 1.2 and 6.8. Infra-red (IR) spectrometry, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), x-ray diffraction (XRD), and atomic absorption spectroscopy (AAS) were also applied to investigate the physicochemical characteristics of the drug in bead formulations. Results: The surface morphology, size, and drug loading of the beads varied with increase in the concentration of chitosan and calcium chloride in the gelation medium. The swelling ability of the beads in different pH media was dependent on the presence of a polyelectrolyte complex in the beads and the pH of the media. Both calcium alginate beads and the beads treated with chitosan failed to release the drug at pH 1.2 over the period of study. On the other hand, at pH 6.8, calcium alginate beads released approx. 96 % of drug in 6 h, but treatment of the beads with chitosan lowered drug release to 73 %. Drug release mechanism was either "anomalous transport" or "case-II transport". Data from characterisation studies indicate that there was no significant change in the physical state of the drug in the bead formulations. Conclusion: Although nimodipine-loaded alginate beads showed poor sustained release characteristics, modification with chitosan yielded beads that exhibited sustained drug release.
 
Phase diagram showing separation/coacervation of sodium alginate, chitosan, and calcium chloride. and
The release profiles of prednisolone from microparticles prepared with sodium alginate and low (f1), medium (f2), or high (f3) MW chitosan.
FTIR spectra of chitosan-sodium alginate microparticles prepared with low, medium and high MW chitosan
Prednisolone content, geometric mean diameter and mucoadhesiveness of microparticles on separated rat small intestine by containing different MW chitosans
Purpose: The aim of the present study was to investigate the effect of chitosan molecular weight on size, size distribution, release rate, mucoadhesive properties and electrostatic bonding of alginate/chitosan microparticles containing prednisolone Methods: Three mucoadhesive alginate/chitosan microparticle formulations, f1, f2 and f3, were prepared using low, medium and high chitosan molecular weight (MW) chitosan, respectively, by directly spraying alginate solution into a solution of chitosan and calcium chloride at optimum conditions. Prednisolone was incorporated in the alginate solution prior to spraying. The microparticles were then evaluated for prednisolone content, size, release rate, and mucoadhesive properties using appropriate methods. The formation of electrostatic and hydrogen bonds between chitosan and alginate was assessed by differential scanning calorimetetry (DSC) and Fourier transform infrared (FTIR). Results: The results indicate that high MW chitosan microparticles were significantly (p<0.05) smaller and more uniform in size, with better mucoadhesive properties and lower release rate than the other formulations. FTIR and DSC studies indicate that stronger hydrogen and electrostatic bonding in the formulation containing high MW chitosan than inthe other formulations Conclusion: The physicochemical properties of chitosan-alginate microparticles are dependent on the molecular weight of chitosan
 
Purpose: This study aims to investigate the therapeutic effects of the aqueous extract of Clitoria ternatea Linn. Fabaceae leaves and flowers on alloxan-induced diabetes in rats. Methods: The effect of orally administered aqueous extracts (400 mg/kg body weight) of Clitoria ternatea leaves and flowers on serum glucose, glycosylated hemoglobin, and insulin were examined in control and extract-treated diabetic rats. The glycogen content of the liver and skeletal muscles of the rats was evaluated while the activities of the glycolytic enzyme, glucokinase, and the gluconeogenic enzyme, glucose-6-phosphatase in the liver were assessed. The extracts were administered over a period of 84 days. Results: The aqueous extracts of Clitoria ternatea leaves and flowers significantly (P<0.05) reduced serum glucose, glycosylated hemoglobin and the activities of gluconeogenic enzyme, glucose-6- phosphatase, but increased serum insulin, liver and skeletal muscle glycogen and the activity of the glycolytic enzyme, glucokinase. For all the biochemical tests performed, the leaf extract-treated rat showed essentially the same profile as those treated with the flower extract. Conclusion: The present investigation suggests that Clitoria ternatea leaf and flower extracts exhibit antihyperglycaemic effect in rats with alloxan-induced diabetes mellitus.
 
Purpose: The objective of this work was to prepare and evaluate fast dissolving tablets of the nutraceutical, freeze dried Aloe vera gel. Methods: Fast dissolving tablets of the nutraceutical, freeze-dried Aloe vera gel, were prepared by dry granulation method. The tablets were evaluated for crushing strength, disintegration time, wetting time, friability, drug content and drug release. A 32 full factorial design was applied to investigate the combined effect of two formulation variables - amounts of microcrystalline cellulose and mannitol. Results: The results of multiple regression analysis revealed that in order to obtain a fast dissolving tablet of the Aloe vera gel, an optimum concentration of mannitol and a higher content of microcrystalline cellulose should be used. A response surface plot was also provided to graphically represent the effect of the independent variables on the disintegration time and wetting time. The validity of the generated mathematical model was tested by preparing a check point batch. Conclusion: This investigation has demonstrated that satisfactory fast dissolving Aloe vera gel tablets can be formulated. It also showed the potential of experimental design in understanding the effect of formulation variables on the quality of fast dissolving tablets.
 
The effect of the extract of A. buettneri on induced hyperthermia. The values represent the mean ± S.E.M. of four rats. * P< 0.05; ** P< 0.01 (extract vs. control).
Purpose: Aloe buettneri A. Berger is commonly used in Togolese folk medicine to treat inflammation and gastric ulcer. In this study we investigated the anti-oedema, analgesic, antipyretic and ulcer healing properties of the hydro-alcohol extract of their leaves. Methods: Rat oedema paw were induced by the injection of 0.1 ml of formaldehyde 1%, tail flick method is used to study analgesic property, hyperthermia was induced by subcutaneous injection of 15% of a brewers' yeast suspension at dose of 10 ml/kg and ulcers were induced by ethanol or HCl/ethanol mixture. Results: The extract showed anti-inflammatory properties at doses between 250-500 mg/kg. It inhibited, in a dose- dependent manner, the oedema induced by 0.1 ml of formaldehyde 1%. Scores of 73.70% and 83.63% were obtned when the doses of extract administered were 100 and 500 mg/kg, respectively. The tail flick analgesic index showed an increase of 36.56% when the dose was 500 mg/kg. The extract decreased significantly the hyperthermia induced by the injection of yeast. 1000 mg/kg of the extract inhibited 63.77% of the gastric lesion induced by acid-water-ethanol mixture while daily administration of the same dose accelerated the cicatrisation of gastric ulcer induced by 95% ethanol. Conclusion: The results obtained show that the hydro-alcohol extract of Aloe buettneri A. Berger (Lilliaceae) has anti-inflammatory, anti-ulcer and wound healing properties
 
1 H and 13 C NMR data for compound AG 11 (a galangoflavonoside)
Purpose: The purpose of this investigation was to isolate novel flavonoids from Alpinia galanga rhizomes. Methods: The methanol extract of Alpinia galanga was subjected to column chromatography and eluted with ethyl acetate-methanol (9:1) to yield a compound, galangoflavonoside (AG 11). The structure of the compound was elucidated by various spectral techniques (UV, IR, 1H NMR, 13C NMR, and MS). Results: Chemical investigation of the extract furnished a new flavonoid galangoflavonoside (AG 11). Conclusion: The isolated compound, galangoflavonoside (AG 11,) could be a potential therapeutic compound as well as serve as a lead compound in the synthesis of other useful flavonoids. Isolation of the galangoflavonoside from Alpinia galanga rhizomes is being reported, to the best of our knowledge, for the first time.
 
The release profile of A. boonei tablets containing the () extract alone, (■) Avicel ® (1:4) as direct compression excipient and (▲) 1%w/w cornstarch as binder compressed at 5KN (Error bars = mean±SD)
Purpose: To formulate the extracts of the stem bark of Alstonia boonei , an important antimalarial herb, into tablet dosage form. Methods: Tablets were formulated using direct compression and wet granulation methods. The mechanical properties of the tablets were assessed using crushing strength and friability and the crushing strength:friability ratio (CSFR) while drug release properties were evaluated using disintegration and dissolution times. Results: There were statistically significant (p<0.01) differences in the CSFR values and drug release properties of A. boonei tablets prepared by both methods. The differences depended on the type and concentration of excipient and binder employed in the formulation. Conclusions: The method of preparation of the A. boonei tablets needs to be carefully selected to ensure the production of tablets with adequate bond strength to withstand the rigours of handling and at the same time release the active compound (s) for biological action.
 
Top-cited authors
Soheyla Honary
Aderonke Adepoju-Bello
  • University of Lagos
Herbert A B Coker
  • University of Lagos
Sunday ADELEKE Adesegun
  • University of Lagos
Temmy Atangbayila
  • University of Lagos