Siriporn Okonogi

Chiang Mai University, Amphoe Muang Chiang Mai, Chiang Mai, Thailand

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Publications (63)107.89 Total impact

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    ABSTRACT: In the present study; the glutinous Niaw Sanpatong (NSP) and Niaw Koko-6 (NKK), and the non-glutinous Jasmine (JM) and Saohai (SH) were chemically modified. The difference of these rice varieties on the physicochemical characteristics of the modified rice powders and the properties of the derived gels were evaluated. X-ray diffractometer was used for crystalline structure investigation of the rice powders and gels. A parallel plate rheometer was used to measure the rheological property of the gels. It was found that the non-glutinous varieties produced gels with higher mucoadhesive properties than the glutinous rice. Rheological behavior of JM and SH gels was pseudoplastic without yield value whereas that of NSP and NKK gels was plastic with the yield values of 1077.4 ± 185.9 and 536.1 ± 45.8 millipascals-second (mPas), respectively. These different properties are considered to be due to the amylose content in different rice variety. The results suggest that the non-glutinous rice varieties with high amylose content are the most suitable for preparing gels as local delivery systems via the mucosal membrane.
    Drug discoveries & therapeutics 07/2015; 9(3):221-8. DOI:10.5582/ddt.2015.01009
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    ABSTRACT: Curcumin (CM) has been reported as a potential anticancer agent. However, its pharmaceutical applications as therapeutic agent are hampered because of its poor aqueous solubility. The present study explores the advantages of polymeric micelles composed of block copolymers of methoxypoly(ethylene glycol) (mPEG) and N-(2-hydroxypropyl) methacrylamide (HPMA) modified with monolactate, dilactate and benzoyl side groups to enhance CM solubility and inhibitory activity against cancer cells. Amphiphilic block copolymers, ω-methoxypoly(ethylene glycol)-b-(N-(2-benzoyloxypropyl) methacrylamide) (PEG-HPMA-Bz) were synthesized and characterized by (1)H-NMR and GPC. One polymer with a molecular weight of 28000 Da was used to formulate CM and compared with other aromatic substituted polymers. CM was loaded by a fast heating method (PEG-HPMA-DL and PEG-HPMA-Bz-L) and a nanoprecipitation method (PEG-HPMA-Bz). Physicochemical characteristics and cytotoxicity/cytocompatibility of CM loaded polymeric micelles were evaluated. It was found that HPMA-based polymeric micelles significantly enhanced the solubility of CM. The PEG-HPMA-Bz micelles showed the best solubilization properties. CM loaded polymeric micelles showed sustained release of the loading CM for more than 20 days. All of CM loaded polymeric micelles formulations showed a significantly potent cytotoxic effect against three cancer cell lines. HPMA-based polymeric micelles are therefore promising nanodelivery systems of CM for cancer therapy. Copyright © 2015 Elsevier B.V. All rights reserved.
    European journal of pharmaceutics and biopharmaceutics: official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V 06/2015; 94. DOI:10.1016/j.ejpb.2015.06.010 · 3.38 Impact Factor
  • Ornchuma Naksuriya · Siriporn Okonogi
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    ABSTRACT: Curcumin has been extensively reported as a potential natural antioxidant. However, there was no data on activity comparison as well as the biological interactions of curcumin with other natural antioxidants. The aim of the present study was to investigate the antioxidant power of curcumin in comparison with three important natural antioxidants; gallic acid, ascorbic acid, and xanthone on free radical scavenging action and their combination effects on this activity. The results indicated that the activities of these compounds were dose-dependent. The 50% effective concentration (EC50) of curcumin was found to be 11 μg/mL. Curcumin showed significantly higher antioxidant activity than ascorbic acid and xanthone but less than gallic acid. Interestingly, curcumin revealed synergistic antioxidant effect when combined with gallic acid whereas the antagonistic effect occurred in curcumin combination with ascorbic acid or xanthone. These results suggest that curcumin-gallic acid combination is the potential antioxidant mixture to be used in place of the individual substance whereas using of curcumin in combination with ascorbic acid or xanthone should be avoid.
    Drug discoveries & therapeutics 05/2015; 9(2):136-41. DOI:10.5582/ddt.2015.01013
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    ABSTRACT: Mammea siamensis is used in traditional Thai medicine. This study was designed to extract and isolate an active compound from the M. siamensis seeds and to investigate its activity on Wilms' tumour 1 (WT1) protein expression in K562 cells. WT1 is a transcription factor that stimulates cell proliferation. The ethanol saraphi seed (ESS) extract was fractionated using n-hexane, ethyl acetate, n-butanol and water to obtain n-hexane saraphi seed (HSS), ethyl acetate saraphi seed (EASS), n-butanol saraphi seed (BSS), and water saraphi seed (WSS) extracts, respectively. The ESS, HSS and EASS extracts had strong cytotoxic effects on K562 cells in the MTT assay. All three fractions decreased WT1 protein levels and decreased total cell numbers. The HSS extract decreased the WT1 protein levels in a time- and dose-dependent manner. HPLC and NMR analyses indicated that the active compound of HSS was mammea E/BB. M. siamensis seeds are thus identified as a promising source of bioactive compounds for potential inhibition of WT1 protein expression.
    Natural Product Research 03/2015; DOI:10.1080/14786419.2015.1017491 · 0.92 Impact Factor
  • Siriporn Okonogi · Pornthida Riangjanapatee
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    ABSTRACT: Nanostructured lipid carriers (NLC) are interesting delivery systems for enhancing the penetration of an active substance through the skin after topical administration. In the present study, lycopene was loaded into NLC, composed of Eumulgin(®) SG, orange wax and rice bran oil, using high pressure homogenization (HPH). Photon correlation spectroscopy analysis showed that the lycopene-loaded NLC had a size of 150-160nm with a relatively small size distribution (PdI <0.15). The entrapment efficiency of lycopene was found to be 100±0%% for all formulations. An in vitro release study of lycopene showed a biphasic release profile: a relatively fast release during the first 6h followed by a sustained release during the next 18h. An in vitro occlusion test showed that the occlusive properties of NLC increased with increasing lycopene loading. A free radical scavenging activity test of the NLC loaded with 50 mg% lycopene showed a Trolox equivalent antioxidant capacity value of 36.6±0.4μM Trolox/mg NLC which is higher than that of the NLC base (26.6±0.1μM Trolox/mg NLC). The concentration of 50% antioxidant activity (IC50) of the lycopene-loaded NLC was 14.1±0.6mg/mL, and lower than that of the formulation without lycopene (17.7±0.4mg/mL). The particle size, size distribution and zeta potential of lycopene-loaded NLC stored at different temperatures of 4, 30, 40°C for 120 days did not change in time, demonstrating an excellent colloidal stability of the systems. Chemical stability data indicated that the utilization of NLC increased the stability of lycopene and it was found that the degradation of lycopene was retarded when stored at low temperatures. In conclusion, NLC are attractive systems for the cutaneous delivery of lycopene. Copyright © 2014. Published by Elsevier B.V.
    International Journal of Pharmaceutics 12/2014; 478(2). DOI:10.1016/j.ijpharm.2014.12.002 · 3.65 Impact Factor
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    ABSTRACT: Leukemia is a hematologic malignancy with a frequent incidence and high mortality rate. Previous studies have shown that the FLT3 gene is overexpressed in leukemic blast cells, especially in acute myeloid leukemia. In this study, a commercially available curcuminoid mixture (1), pure curcumin (2), pure demethoxycurcumin (3), and pure bisdemethoxycurcumin (4) were investigated for their inhibitory effects on cell growth, FLT3 expression, and cell cycle progression in an FLT3-overexpressing EoL-1 leukemic cell line using an MTT assay, Western blotting, and flow cytometry, respectively. The mixture (1) and compounds 2-4 demonstrated cytotoxic effects with IC50 values ranging from 6.5 to 22.5 μM. A significant decrease in FLT3 protein levels was found after curcuminoid treatment with IC20 doses, especially with mixture 1 and compound 2. In addition, mixture 1 and curcumin (2) showed activity on cell cycle arrest at the G0/G1 phase and decreased the FLT3 and STAT5A protein levels in a dose-dependent manner. Compound 2 demonstrated the greatest potential for inhibiting cell growth, cell cycle progression, and FLT3 expression in EoL-1 cells. This investigation has provided new findings regarding the effect of turmeric curcuminoids on FLT3 expression in leukemic cells.
    Journal of Natural Products 04/2014; 77(4). DOI:10.1021/np401028h · 3.80 Impact Factor
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    ABSTRACT: Curcumin, a natural yellow phenolic compound, is present in many kinds of herbs, particularly in Curcuma longa Linn. (turmeric). It is a natural antioxidant and has shown many pharmacological activities such as anti-inflammatory, anti-microbial, anti-cancer, and anti-Alzheimer in both preclinical and clinical studies. Moreover, curcumin has hepatoprotective, nephroprotective, cardioprotective, neuroprotective, hypoglycemic, antirheumatic, and antidiabetic activities and it also suppresses thrombosis and protects against myocardial infarction. Particularly, curcumin has demonstrated efficacy as an anticancer agent, but a limiting factor is its extremely low aqueous solubility which hampers its use as therapeutic agent. Therefore, many technologies have been developed and applied to overcome this limitation. In this review, we summarize the recent works on the design and development of nano-sized delivery systems for curcumin, including liposomes, polymeric nanoparticles and micelles, conjugates, peptide carriers, cyclodextrins, solid dispersions, lipid nanoparticles and emulsions. Efficacy studies of curcumin nanoformulations using cancer cell lines and in vivo models as well as up-to-date human clinical trials are also discussed.
    Biomaterials 01/2014; 35(10). DOI:10.1016/j.biomaterials.2013.12.090 · 8.56 Impact Factor
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    ABSTRACT: The aim of this work was to investigate the suitable rice varieties for developing pharmaceutical buccal films. Two rice varieties with extreme difference in amylose content were used. Rice powders were chemically modified to yield the carboxymethyl rice prior to film preparation. Scanning electron microscope (SEM) and X-ray diffractometer (XRD) were used to investigate the solid structure of rice powders. The results indicated that amylose content in the rice grains played the effects on the morphology and crystalline structure of the modified rice powders as well as the film properties. The modified rice powders of low amylose content showed halo pattern XRD whereas some crystalline peaks could be observed from the high amylose content modified rice powders. Adding of glycerin caused the films better properties of more transparency and getting rid of air bubbles. High amylose rice films showed more transparency and higher mucoadhesive property and was considered to be suitable for incorporating the drug. Adding of surfactant caused the increase in tensile strength and decrease in elongation of the rice films. The most suitable surfactant for diclofenac buccal rice film is Tween 20. This study demonstrates that rice grains are the promising natural source for pharmaceutical film forming agent. Suitable pharmaceutical buccal films could be developed from the rice with high amylose content.
    Drug discoveries & therapeutics 01/2014; 8(6):262-267. DOI:10.5582/ddt.2014.01041
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    ABSTRACT: In the treatment of mild to medium severe atopic dermatitis a new formulation proved to be highly efficient. The formulation is based on a combination of microsilver and Nano Lipid Carriers (NLC) incorporated into an o/w cream and a lotion. A theory of action was proposed, the formation of a silver-NLC complex (sNLC). In this study this theory was proven, and based on this new mechanism two new approaches for dealing with AD are suggested to distinctly improve AD treatment, i.e. increasing efficiency, reducing drug exposure and reducing side effects. The antimicrobial silver ions adsorb onto the surface of the negatively charged NLC (= sNLC complex). The sNLC as nanoparticles are highly adhesive to skin and bacterial surfaces, leading to a locally high concentration of silver ions killing the bacteria, much more effective than silver alone. The NLC restore the distorted skin barrier. Based on this a new two-step approach is suggested: 1. "treatment-supportive consumer care" by restoring the normal skin condition (NLC for barrier restoration plus synergistic antibacterial silver-NLC complex) and 2. "drug-loaded consumer care AD formulations". i.e. incorporating drugs into the NLC of this consumer care formulation. NLC incorporation makes the drugs more effective (penetration enhancement) and simultaneously exploits the skin normalization ability of the skin care sNLC formulation, future drug candidates being prednicarbate and tacrolimus.
    International Journal of Pharmaceutics 12/2013; 462(1-2). DOI:10.1016/j.ijpharm.2013.12.044 · 3.65 Impact Factor
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    ABSTRACT: Nanostructured lipid carriers (NLC) were developed using a skin-compatible surfactant and natural lipid materials (rice oil, cholesterol) to incorporate lycopene. Characteristics of the NLC were explored in comparison with nanoemulsions and solid-lipid nanoparticles (SLN). Photon correlation spectroscopy, laser diffractometry (LD) and differential scanning calorimetry were used to determine particle size and thermal stability. Particle size expressed as LD (0.99) was 405 nm for the SLN, 350 nm for the NLC without cholesterol and 287 nm for the NLC with cholesterol. Rice oil and cholesterol enabled the formation of smaller particles, but cholesterol also reduced drug stability in the NLC. To preserve chemical stability of lycopene in the NLC, cholesterol should be avoided and storage should be at 4 degrees C or at room temperature.
    Pharmazie 09/2013; 68(9):723-31. DOI:10.1691/ph.2013.2139 · 1.05 Impact Factor
  • Siriporn Okonogi · Pornthida Riangjanapatee
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    ABSTRACT: Abstract Context: The advantage of solid nanocarriers like solid lipid nanoparticles (SLN) or nanostructured lipid carriers (NLC) is related to some degree of crystalline characteristics of the lipid. However, the detection of tiny content of crystalline structure in such nanoparticles is difficult. Objective: The aim of this study was to explore a potential method for detection of low degree of crystalline characteristics of lycopene-loaded SLN and NLC. Methods: Crystalline characteristics investigation was done by polarized light microscope (PLM), differential scanning calorimeter (DSC), X-ray diffractometer (XRD) and transmission electron microscope (TEM). Results and discussion: It was found that high crystalline characteristics as anisotropic molecular organization crystal of pure orange wax and lycopene could be investigated by PLM, DSC and WAXS. Low crystallinity of lycopene-loaded SLN and NLC could not be detected by those techniques. Electron diffraction mode of TEM showed potential detection of tiny crystalline characteristics of such systems. The diffraction pattern of lycopene-loaded SLN and NLC exhibited obvious zero order laue zone indicating an isotropic fine grained polycrystalline of the nanoparticles. Conclusion: It could be concluded that TEM is a promising method for detection of low-level crystallinity of solid nanocarriers.
    Drug Development and Industrial Pharmacy 08/2013; 40(10). DOI:10.3109/03639045.2013.828215 · 2.10 Impact Factor
  • Wantida Chaiyana · Thomas Rades · Siriporn Okonogi
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    ABSTRACT: The aims of the present study were to characterize the microstructure and study the skin permeation enhancement of formulations containing the alkaloidal extract from Tabernaemontana divaricata. The extract was loaded in the formulations composed of Zingiber cassumunar oil, TritonX-114, ethanol and water with the oil:surfactant ratios of 1:5 and 2:5. The formulations were characterized by photon correlation spectroscopy, polarising light microscopy, differential scanning calorimetry, and viscosity measurement. A reverse micellar phase, w/o microemulsions, liquid crystalline systems, liquid crystal in microemulsion systems and coarse emulsions were formed along the aqueous dilution line of both oil:surfactant ratios. Formulations with the ratio of 1:5 containing 0.1μg/ml extract showed a significantly higher acetylcholinesterase inhibition than those with the ratio of 2:5. The skin of stillborn piglet was used in the permeation study. The liquid crystalline and microemulsion systems significantly increased the transdermal delivery of the extract within 24h. It was concluded that the alkaloidal extract from T. divaricata stem loaded in liquid crystalline or microemulsion systems comprising Z. cassumunar oil/TritonX-114/ethanol/water may act as an alternative percutanous formulations for enhancing the acetylcholine level in Alzheimer's patients.
    International Journal of Pharmaceutics 05/2013; 452(1–2). DOI:10.1016/j.ijpharm.2013.05.005 · 3.65 Impact Factor
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    ABSTRACT: Guided by the acetylcholinesterase inhibiting activity, the bisindole alkaloid 3'-R/S-hydroxyvoacamine was isolated from a stem extract of Tabernaemontana divaricata, a plant used in Thailand in traditional rejuvenation remedies for improving the memory. The structure of the alkaloid was elucidated by extensive use of NMR spectroscopy and the complete assignment of the (1)H and (13)C NMR spectra is reported. The alkaloid acted as a non-competitive inhibitor against AChE with an IC(50) value of 7.00±1.99μM. An HPLC method was developed for the quantitative analysis of the AChE inhibitor. It suggested that there was 12.4% (w/w) of 3'-R/S-hydroxyvoacamine in the alkaloid enriched fraction of T. divaricata stem.
    Phytomedicine: international journal of phytotherapy and phytopharmacology 01/2013; 20(6). DOI:10.1016/j.phymed.2012.12.016 · 3.13 Impact Factor
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    ABSTRACT: Context: The number of patients with cancer is increasing. New therapeutic agents to overcome drug-resistant tumors are urgently needed. Cyrtosperma johnstonii N.E. Br. (Araceae) is used for treatment of cancer in Thai traditional medicine. This study aimed to evaluate antioxidant activity and cytotoxicity of C. johnstonii extracts on human cancer cells. Materials and methods: Dried powder of C. johnstonii rhizomes was extracted with several solvents. The 0.1 mg/ml extract solution was tested for antioxidant activity by 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and ferric reducing antioxidant power (FRAP) assays. Color formation from 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was used to determine cell viability. Standardization of the extract was performed by high-performance liquid chromatography (HPLC) with photodiode array detector at 254 and 360 nm. Cell cycle arrest was evaluated by flow cytometry after 5 min, 12 h and 24 h treated with 20 µg/ml of the acetone extract. Results: The acetone extract exhibited the highest phenolic content and antioxidant activity (TEAC and EC values = 19.2 ± 0.14 and 19.2 ± 0.31 mM/mg, respectively). The IC₅₀ values for leukemia ranged from 11 ± 1 to 29 ± 3 µg/ml and from 5 ± 2 to 6 ± 0 µg/ml for small cell lung carcinoma cells. Cell cycle arrest occurred at the G2/M phase followed by apoptosis. HPLC analysis revealed that rutin is the major constituents of the extract. Discussion and conclusion: The acetone extract of C. johnstoni is a promising source of natural antioxidants and anticancer. The extract inhibits cancer cells effectively with less effect on normal cells.
    Pharmaceutical Biology 11/2012; 51(3). DOI:10.3109/13880209.2012.729064 · 1.24 Impact Factor
  • S Okonogi · W Chaiyana
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    ABSTRACT: The aim of the present study was to enhance the cholinesterase inhibitory activity of Zingiber cassumunar (ZC) oil using a microemulsion (ME) technique. Pseudoternary phase diagrams of the oil, water, and surfactant/co-surfactant mixture were constructed using a water titration method. Effects of co-surfactant, surfactant/co-surfactant ratio, ionic strength, and pH were examined by means of the microemulsion region which existed in the phase diagrams. The inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were tested by Ellman's colorimetric assay. It was found that ZC oil possesses inhibitory activity against not only AChE but also BChE. Formulation of ZC oil as ME revealed that alkyl chain length and number of hydroxyl groups of co-surfactant exhibited a remarkable effect on the pseudoternary phase diagram. Longer alkyl chains and more hydroxyl groups gave smaller regions of MEs. Ionic strength also affected the ME region. However, the phase behavior was hardly influenced by pH. The suitable ZC oil ME was composed of Triton X-114 in combination with propylene glycol. The anti-cholinesterase activity of this ME was much higher than that of native ZC oil. It exhibited twenty times and twenty five times higher inhibitory activity against AChE and BChE, respectively. ZC oil loaded ME is an attractive formulation for further characterization and an in vivo study in an animal model with Alzheimer's disease.
    Drug discoveries & therapeutics 10/2012; 6(5):249-55.
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    Pornthida Riangjanapatee · Siriporn Okonogi
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    ABSTRACT: Nanostructured lipid carriers (NLC) have gained high interest as enhancing drug delivery systems via topical application during the last few years. NLC can enhance stability of many active substances against environmental stress. The extremely small size of NLC plays an important role in skin penetration. The unchanged size of NLC upon storage indicates its physical stability. The aim of this work was to investigate the effect of surfactant type on physical properties and stability of lycopene-loaded NLC. The preparation of the NLC was achieved by means of high pressure homogenization. The results indicate that different types of surfactant yield NLC with different properties. We also explored the effect of contact angle on the size of the NLC. It was found that the small contact angle gave NLC with small size. Among two small contact angle surfactants, Plantacare 1200 gave lycopene-loaded NLC with smaller size, higher zeta potential and narrower size distribution. The particle size, size distribution, and zeta potential of lycopene-loaded NLC prepared with Plantacare 1200 was unchanged during 30 days of storage. It was concluded that Plantacare 1200 is the most suitable surfactant for lycopene-loaded NLC. The chemical stability of lycopene entrapped in the NLC was significantly enhanced.
    Drug discoveries & therapeutics 06/2012; 6(3):163-8.
  • Wantida Chaiyana · Siriporn Okonogi
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    ABSTRACT: Inhibition of cholinesterase has attracted much attention recently because of its potential for the treatment of Alzheimer's disease. In this work, the anticholinesterase activities of plant oils were investigated using Ellman's colorimetric method. The results indicate that essential oils obtained from Melissa officinalis leaf and Citrus aurantifolia leaf showed high acetylcholinesterase and butyrylcholinesterase co-inhibitory activities. C. aurantifolia leaf oil revealed in this study has an IC(50) value on acetylcholinesterase and butyrylcholinesterase of 139 ± 35 and 42 ± 5 μg/ml, respectively. GC/MS analysis revealed that the major constituents of C. aurantifolia leaf oil are monoterpenoids including limonene, l-camphor, citronellol, o-cymene and 1,8-cineole.
    Phytomedicine: international journal of phytotherapy and phytopharmacology 04/2012; 19(8-9):836-9. DOI:10.1016/j.phymed.2012.03.010 · 3.13 Impact Factor
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    ABSTRACT: Xanthone exhibits several medicinal activities and especially it inhibits the growth of cancer cells. However, the use of xanthone is limited because of its low aqueous solubility and systemic toxicity. In the present study xanthone was loaded into poly(ethylene glycol)-b-poly[N-(2-hydroxypropyl) methacrylamide-dilactate] mPEG-b-p(HPMAm-Lac(2)) micelles in order to overcome these drawbacks. It was shown that xanthone could be loaded in these micelles up to 2 mg/mL with ~100% entrapment efficiency and ~20% loading capacity. The average particle diameter of the xanthone loaded mPEG-b-p(HPMAm-Lac(2)) micelles as determined by dynamic light scattering ranged from 84 to 112 nm. In vitro assays showed that xanthone in its free form as well as loaded in polymeric micelles had a high cytotoxicity towards both doxorubicin sensitive and, importantly, resistant cancer cells. On the other hand empty mPEG-b-p(HPMAm-Lac(2)) micelles did not show any cytotoxicity towards normal cells (PBMCs). Interestingly, the cytostatic effect of xanthone towards normal cells was masked when loaded in the micelles. The mechanism of cell growth inhibition by xanthone-loaded polymeric micelles was mediated through induction of apoptosis, as evidenced from a subdiploid peak of propidium iodide stained cells using flow cytometric analysis. From the results of this study it can be concluded that xanthone has potent anticancer activity not only on sensitive but also on doxorubicin resistant cancer cell lines. mPEG-b-p(HPMAm-Lac(2)) micelles are therefore attractive delivery systems of xanthone for the treatment of cancer.
    Colloids and surfaces B: Biointerfaces 02/2012; 94:266-73. DOI:10.1016/j.colsurfb.2012.02.002 · 4.15 Impact Factor
  • W Nantitanon · S Okonogi
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    ABSTRACT: In the present study, quercetin (QT), morin (MR), and quercetin-3-O-glucopyranoside (QG) isolated from guava leaves were comparatively tested for antioxidant activity using DPPH, ABTS, and FRAP methods. QT was the most active among them. The free radical scavenging activity of QT was approximately four times higher than MR and two times higher than QG. The reducing power of QT was eight times higher than MR and two times higher than QG. A mixture of QT with MR or QG showed interesting combination effect. The synergistic antioxidant activity was obtained when QT was mixed with MR whereas the antagonistic effect was found when mixed with QG. The stability study of QT in liquid preparations indicated that the decomposition reaction rate of QT could be explained by a kinetic model assuming a first-order chemical reaction. The aqueous solution of QT was rapidly decomposed with t1/2 of approximately five days whereas QT entrapped in chitosan nanoparticles was five times longer. It was concluded that QT was the most active antioxidant from guava leaves. Entrapment of QT in chitosan nanoparticles could significantly enhance its stability.
    Drug discoveries & therapeutics 02/2012; 6(1):38-43.
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    ABSTRACT: An investigation and comparison of solubility, viscosity and rheological properties under neutral, acidic and alkaline conditions of water-soluble chitosan derivatives, viz. O-carboxymethyl chitosan, N,O-carboxymethyl chitosan, N-[(2-hydroxy-3-trimethylammonium)propyl] chitosan chloride and O-carboxymethyl-N-[(2-hydroxy-3-trimethylammonium)propyl] chitosan chloride, was undertaken. © 2012 by Maejo University, San Sai, Chiang Mai, 50290 Thailand.
    Maejo international journal of science and technology 01/2012; 6(2):315-322. · 0.37 Impact Factor

Publication Stats

635 Citations
107.89 Total Impact Points


  • 1991–2015
    • Chiang Mai University
      • • Department of Pharmaceutical Sciences
      • • Faculty of Pharmacy
      Amphoe Muang Chiang Mai, Chiang Mai, Thailand
  • 2001
    • Mahidol University
      • Faculty of Pharmacy
      Krung Thep, Bangkok, Thailand
  • 1993–1995
    • Chiba University
      • Faculty of Pharmaceutical Sciences
      Tiba, Chiba, Japan