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ABSTRACT: Abstract Objective: To explore the suitable application of MCM-41 (Mobil Composition of Matter number forty-one)-type and MCM-48-type mesoporous silica in the oral water insoluble drug delivery system. Methods: Cilostazol (CLT) as a model drug was loaded into synthesized MCM-48 (Mobil Composition of Matter number forty-eight) and commercial MCM-41 by three common methods. The obtained MCM-41, MCM-48 and CLT-loaded samples were characterized by means of nitrogen adsorption, thermogravimetric analysis, ultraviolet-visible spectrophotometry, scanning electron microscopy, transmission electron microscopy, differential scanning calorimetry and powder X-ray diffractometer. Results: It was found that solvent evaporation method was preferred according to the drug loading efficiency and the maximum percent cumulative drug dissolution. MCM-48 with 3D cubic pore structure and MCM-41 with 2D long tubular structure are nearly spherical particles in 300-500 nm. Nevertheless, the silica carriers with similar large specific surface areas and concentrating pore size distributions (978.66 m(2)/g, 3.8 nm for MCM-41 and 1108.04 m(2)/g, 3.6 nm for MCM-48) exhibited different adsorption behaviors for CLT. The maximum percent cumulative drug release of the two CLT/silica solid dispersion (CLT-MCM-48 and CLT-MCM-41) was 63.41% and 85.78% within 60 min, respectively; while in the subsequent 12 h release experiment, almost 100% cumulative drug release were both obtained. In the pharmacokinetics aspect, the maximum plasma concentrations of CLT-MCM-48 reached 3.63 mg/L by 0.92 h. The AUC0-∞ values of the CLT-MCM-41 and CLT-MCM-48 were 1.14-fold and 1.73-fold, respectively, compared with the commercial preparation. Conclusion: Our findings suggest that MCM-41-type and MCM-48-type mesoporous silica have great promise as solid dispersion carriers for sustained and immediate release separately.
Drug Development and Industrial Pharmacy 04/2013; · 1.49 Impact Factor
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ABSTRACT: Abstract Background: Organic porous material is a promising carrier for enhancing the dissolution of poorly water soluble drug. The aim of the present study was to enhance dissolution and oral bioavailability of lovastatin (LV) by preparing a porous starch microsphere foam (PSM) using a novel method, meanwhile, looking into the mechanism of improving dissolution of LV. Methods: PSM was prepared by the W/O emulsion - freeze thawing method. The porous structure of PSM was characterized by scanning electron microscopy (SEM) and nitrogen adsorption/desorption analysis. The adsorption role of nanopores on the drug dissolution and physical state of LV was systematically studied by instrumental analysis, and in vitro and in vivo drug dissolution studies. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to evaluate carrier cytotoxicity. Results: The SEM images of PSM showed nanometer-sized pores. Physical state characterization indicated that porous structure effectively limited the degree of crystallinity of LV. The results of in vitro and in vivo tests testified that PSM accelerated the release of LV and enhanced its oral bioavailability in comparison with crude LV and commercial capsules. The loaded PSM powder indicated a good physical stability under storage for 12 months. MTT assay shows PSM has no toxicity for Caco-2 cell. Conclusion: The preparation was a promising method to produce small and uniform PSM with markedly enhanced dissolution rate and oral bioavailability due to the spatial confinement effect of porous structure. The present work demonstrates the significant potential for the use of PSM as a novel delivery system for poorly water soluble drugs.
Drug Development and Industrial Pharmacy 02/2013; · 1.49 Impact Factor
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ABSTRACT: The central purpose of this study was to evaluate the impact of drug particle size and crystalline state on valsartan (VAL) formulations in order to improve its dissolution and bioavailability. VAL microsuspension (mean size 22μm) and nanosuspension (30-80nm) were prepared by high speed dispersing and anti-solvent precipitation method and converted into powders through spray drying. Differential scanning calorimetry studies indicated amorphization of VAL in the spray-dried valsartan nanosuspension (SD-VAL-Nano) but recrystallization occurred after 6 months storage at room temperature. The spray-dried valsartan microsuspension (SD-VAL-Micro) conserved the crystalline form. The VAL dissolution rate and extent were markedly enhanced with both SD-VAL-Micro and SD-VAL-Nano as compared to crude VAL crystals over the pH range of 1.2 to 6.8. Pharmacokinetic studies in rats demonstrated a 2.5-fold increase in oral bioavailability in the case of SD-VAL-Nano compared with the commercial product while the SD-VAL-Micro provided a much less desirable pharmacokinetic profile. In conclusion, reducing particle size to the nano-scale appears to be a worthwhile and promising approach to obtain VAL products with optimum bioavailability. In addition, the impact of crystalline state on the bioavailability of nano-sized VAL might be not as big as that of particle size.
International journal of pharmaceutics 12/2012; · 2.96 Impact Factor
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ABSTRACT: A novel spherical nanosilica matrix (SNM) together with chitosan (CTS) encapsulated SNM (CTS-SNM) was developed in order to investigate the feasibility of using biocompatible chitosan to regulate the drug release rate from porous silica and obtain an oral sustained drug delivery system for the poorly water-soluble drug carvedilol. To achieve this goal, we synthesized a spherical nanosilica matrix (SNM) and incorporated chitosan chains on the SNM surface. A classical solvent evaporation method was adopted to load carvedilol into SNM and CTS-SNM. The physicochemical properties of the drug carriers and the drug loaded composites were systematically studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption, X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and ultraviolet-visible spectrophotometry (UV). The structural changes in CTS-SNM at different times in simulated gastrointestinal fluid as well as the relationships between the swelling effect of chitosan and the in vitro drug release behaviors were also systematically investigated. Pharmacokinetic and bioavailability aspects were also discussed. The results obtained showed that the powerful dispersing effect of SNM and the blocking action due to the swelling of chitosan were the two main factors contributing to the sustained release of this poorly water-soluble drug. The swelling effect of chitosan in an acidic environment together with the shrinking effect in a relatively alkaline environment allowed regulation of the drug release behavior in simulated gastrointestinal fluid. An in vivo study showed that the bioavailability of CAR was improved 182% compared with that of the commercial capsule when SNM was used as the drug carrier. As for CAR-CTS-SNM, the Tmax of CAR was delayed by about 3.4 hour and the bioavailability was slightly increased in comparison with the commercial capsule. We believe that SNM and the chitosan grafted silica developed in this study will help increase the use of polymers and inorganic materials in pharmaceutical applications and stimulate the design of oral drug delivery systems for the immediate or sustained release of poorly water-soluble drugs.
ACS Applied Materials & Interfaces 12/2012; · 4.53 Impact Factor
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ABSTRACT: Three dimensionally ordered macroporous (3DOM) chitosan (3D-CS) matrix with interconnected pores in the nanometer range was developed as a drug carrier for the first time. 3D-CS was prepared using a template-assisted assembly and characterized by SEM, TGA, N(2) adsorption and FT-IR. As a model drug, nimodipine (NMDP) was incorporated into the pores of 3D-CS matrix. The solid state properties of NMDP-loaded samples were characterized by SEM, XRD, DSC and FT-IR. Dissolution studies showed that release behavior of the drug was markedly affected by the particle size of the matrix. With a relatively small matrix particle size, formulations of NMDP-3D-CS-0.5 and NMDP-3D-CS-1 exhibited rapid release patterns. However, on increasing the amount of carrier, release rate of the drug decreased. The pH-dependent slow-release characteristic of 3D-CS matrix delivery system was demonstrated by investigating the release behavior of NMDP at different pH values.
Carbohydrate polymers. 11/2012; 90(4):1648-55.
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ABSTRACT: To prepare stable polyion complex (PIC) micelles, polyasparthydrazide (PAHy) modified with glycidyltrimethylammonium groups and methoxy poly(ethylene glycol) (mPEG) (mPEG-g-PAHy-GTA) was synthesized. The cytotoxicity of the polymer was evaluated by the methyl tetrazolium assay. The polymer entrapped the diammonium glycyrrhizinate (DG) and formed polyion complexes. The effect of pH value, grafting degree of mPEG, copolymer and drug concentration on the micelle formation was investigated by means of measuring entrapment efficiency and micelle size. In vitro DG release from the PIC micelles was detected by dialysis in various media of different ionic strengths. To examine the pharmacokinetic behavior of micelles in vivo, the time course of the drug in plasma was evaluated. The cytotoxicity of the polymer was very low. The results showed that entrapment efficiency can reach about 93%, and the mean particle size was almost 50 nm. The drug release rate decreased with a decrease in ionic strength of the release medium or an increase in the PEG grafting degree. Compared with DG solution, the AUC of DG micelles had a twofold increase. The smaller clearance and longer mean residence time of the DG micelles group compared with DG solution group showed that the DG loaded in PIC micelles can reduce drug elimination and prolong the drug residence time in the blood circulation. The results indicated that PIC micelles composed of mPEG-g-PAHy-GTA would be prospective as a drug carrier to the drugs which can be ionized in solution.
AAPS PharmSciTech 10/2012; · 1.43 Impact Factor
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ABSTRACT: Fibrous ordered mesoporous carbon (FOMC) was developed as a new drug delivery system for loading an insoluble drug, designed to be orally administered, and then to enhance the drug loading capacity, improve the dissolution rate, enhance the oral bioavailability and reduce the gastric damage. Celecoxib (CEL) was chosen as a model drug. The nanostructures and effect of different pore sizes (4.4-7.0 nm) on drug loading and release properties were studied. The results showed that FOMC has a high drug loading capacity (0.599 g/g, drug weight/carrier weight) and the dissolution rate of CEL from FOMC was much faster than pure crystalline CEL using buffer (pH 6.8) as a dissolution medium. Moreover, the oral bioavailability of CEL loaded into FOMC was significantly improved compared with that of CEL capsules and the gastric damage caused by CEL which was loaded in FOMC was also reduced, demonstrating the protective effect of FOMC.
European journal of pharmaceutical sciences: official journal of the European Federation for Pharmaceutical Sciences 04/2012; 45(5):639-47. · 2.61 Impact Factor
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ABSTRACT: Background: Simvastatin is classified as a Biopharmaceutics Classification System (BCS) Class-II compound with a poor aqueous solubility and an acceptable permeability through biomembranes. The strategy of increasing the in vitro dissolution has the potential to enhance the oral bioavailability when using nanosized crystalline drugs. Objective: The aim of this article was to prepare simvastatin nanocrystals to enhance its dissolution rate and bioavailability by exploiting sonoprecipitation. Methods: Injecting 0.50% (w/v) methanol solution of simvastatin into 0.20% (w/v) water solution of F68 under sonication amplitude of 400 W and processing temperature of 3°C. Results: Simvastatin nanocrystal with average diameter of 360 ± 9 nm could be obtained. X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC) confirmed the decreased crystallinity of nanoparticles stabilized by F68. The results of in vitro study demonstrated that the saturation solubility and dissolution rate of simvastatin nanocrystals were enhanced by 1 fold and 4 fold respectively, compared with crude simvastatin and the dissolution rate improved with the decrease in particle size. The C(max) and AUC((0-24 h)) values of simvastatin nanocrystal group were approximately 1.50-fold and 1.44-fold greater than that of simvastatin nanocrystal group, respectively. Additionally, the T(max) of simvastatin nanocrystal group was 1.99 h, comparing to 2.88 h of reference group. Conclusion: Sonoprecipitation method can produce small and uniform simvastatin nanocrystals with an improved saturation solubility, dissolution rate and oral bioavailability.
Drug Development and Industrial Pharmacy 01/2012; 38(10):1230-9. · 1.49 Impact Factor
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ABSTRACT: We investigate the effects of spherical mesoporous silica nanoparticles (MSNs) as an oral drug delivery system to improve the oral bioavailability of the model drug telmisartan (TEL) and examine their cellular uptake and cytotoxicity. Further, we explore the mechanisms behind the improved oral absorption of poorly soluble drugs promoted by MSNs. An investigation of intestinal epithelial cellular binding, association and uptake was carried out by laser scanning confocal microscopy, transmission electron microscopy and fluorescence activated cell sorting. The results show that the cellular uptake is highly time-, concentration- and size-dependent. The model drug permeability studies in the human colon carcinoma (Caco-2) cell lines indicated that MSNs could significantly enhance TEL permeability and reduce rate of drug efflux. After loading TEL into MSNs, its oral bioavailability was compared with that of the marketed product Micardis and TEL-loaded ordered mesoporous silica microparticles (MSMs) in beagle dogs. The relative bioavailability of TEL-loaded MSN formulation and TEL-loaded MSM formulation was 154.4 ± 28.4% and 129.1 ± 15.6%, respectively. MSNs offer the potential to achieve enhanced oral bioavailability of poorly soluble drugs via improved drug dissolution rate and enhanced drug permeability.
Molecular Pharmaceutics 01/2012; 9(3):505-13. · 4.78 Impact Factor
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ABSTRACT: In this study, uniform mesoporous carbon spheres (UMCS) with 3-D pore system and fibrous ordered mesoporous carbon (FOMC) with 2-dimensional hexagonal mesoporous structure were studied as drug carriers for oral drug delivery system. Lovastatin (LOV), which has low water solubility, was chosen as a model drug. Drug release rate and degree of drug loading of UMCS and FOMC were compared. The effects of different pore channel structures and pore sizes on LOV uptake and release were systematically investigated. Cytotoxicity of UMCS and FOMC on human colon carcinoma (Caco-2) cells were also studied. The results indicate that UMCS has a higher degree of drug loading (up to 36.26% drug weight/total weight) compared with FOMC. The dissolution rate of LOV from UMCS was found to be markedly increased compared with pure crystalline LOV, and the dissolution rate of LOV from FOMC was relatively sustained compared with UMCS, and both UMCS and FOMC exhibited a weak cytotoxicity at tested concentrations (10-800 μg/ml).
European journal of pharmaceutics and biopharmaceutics: official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V 12/2011; 80(3):535-43. · 3.15 Impact Factor
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ABSTRACT: The aim of this study was to investigate the correlation between the growth behaviour and in-vitro dissolution rate of water-insoluble drugs prepared with high-shear wet granulation.
Granules containing nimodipine, microcrystalline cellulose, low-substituted hydroxypropylcellulose and aqueous solution of hydroxypropylcellulose were prepared and the effects of independent process variables, including impeller speed and liquid-to-solid ratio were taken into consideration. The mean granule size, granule-size distribution (GSD), porosity and surface properties were monitored at different kneading times to identify the granule-growth mechanisms simultaneously. A computer-based method was applied to simulate the dissolution behaviour of polydisperse granules based on the GSD data.
The in-vitro dissolution rate of drug was high for the early stages of granulation and sharply decreased when coalescence and consolidation of granules started, approaching a flat and low level when granules were sufficiently consolidated. The simulated dissolution results were in agreement with experimental observations and were significantly affected by the GSD, porosity and surface properties of granules during the granulation process. Moreover the GSD was directly related to the granule-growth behaviour and mechanisms.
In general, it was concluded that the dissolution properties of nimodipine basically correlated with the growth behaviour of granules in a high-shear mixer. The simulation method based on GSD can be used as a convenient and rapid way to predict the dissolution properties for formulation development and granulation optimization.
The Journal of pharmacy and pharmacology. 12/2011; 63(12):1548-58.
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ABSTRACT: A facile and simplified method was developed for the synthesis of 3D cubic mesoporous SBA-16 with both a spherical morphology and controllable pore size. The addition of CTAB during the synthesis allowed not only good control over the macroscopic morphology but also a significant reduction in the synthesis time. Notably, the pore size can simultaneously be adjusted by simply controlling the heating temperature. The pharmaceutical performance of the resulting SBA-16 for the delivery of the water-insoluble drug indomethacin (IMC), a non-steroidal anti-inflammatory agent used as a model drug, was systematically studied using nitrogen adsorption, powder X-ray diffraction, differential scanning calorimetry, infrared spectrometry and in vitro dissolution investigations. It was found that IMC could be effectively loaded into mesoporous SBA-16 via the solvent deposition method. An altered physical state and a marked improvement in the dissolution rate were observed for IMC after being loaded into SBA-16 microspheres. In particular, SBA-16 microspheres with the largest pore size (9.0 nm) and highly open and accessible pore networks exhibited the fastest drug release profile. We envisage that the improved drug delivery profiles obtained using SBA-16 as described in our work will offer an interesting option for the formulation of poorly water-soluble drugs.
Journal of Colloid and Interface Science 07/2011; 363(1):410-7. · 3.07 Impact Factor
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ABSTRACT: In the present study, we exploited for the first time the potential of 3-D ordered macroporous (3DOM) silica as matrix for drug nanoparticles, in order to obtain proper control over drug particle size in the sub-micrometer range, enhance the dissolution rate, and reduce gastric damage. 3DOM silica matrix with 3-D spherical pores of 200 nm was successfully created and then loaded with IMC nanoparticles at various drug-silica ratios. A rapid release profile for IMC nanoparticle formulations was achieved in comparison with microsized IMC and a commercial capsule, which could be attributed to both increase in the specific surface area and decrease in the crystallinity of IMC, as well as the hydrophilic surface and the interconnected pore networks of 3DOM silica. Reduced gastric damage of IMC was demonstrated, and the protective effect may arise from the reduction in drug particle size as well as encapsulation effect of 3DOM silica.
European journal of pharmaceutics and biopharmaceutics: official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V 07/2011; 79(3):544-51. · 3.15 Impact Factor
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ABSTRACT: The purpose of this study was to develop spherical mesocellular foam (MCF) loaded with a poorly water-soluble drug, intended to be orally administered, able to improve the dissolution rate and enhance the drug loading capacity. Spherical MCF with a continuous 3-D pore system was synthesized using Pluronic 123 triblock polymer (P123) as a surfactant coupled with cetyltrimethyl ammonium bromide (CTAB) as a co-surfactant. A model drug, simvastatin (SV), was loaded onto spherical MCF via a procedure involving a combination of adsorption equilibrium and solvent evaporation. The drug release rate and the drug loading efficiency of spherical MCF were compared with those of fibrous SBA-15. Investigations using nitrogen adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and HPLC demonstrated the successful incorporation of SV into the MCF host. It was found that spherical MCF has a high drug loading efficiency up to 37.5%, and higher than that of fibrous SBA-15 with a pore diameter of 6.5 nm. It is worth noting that fast release rate of SV was obtained from spherical MCF compared with SBA-15 and pure crystalline SV using enzyme-free simulated intestinal fluid (SIF, pH 6.8).
International journal of pharmaceutics 05/2011; 410(1-2):118-24. · 2.96 Impact Factor
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ABSTRACT: The objective of the present study was to investigate the mechanism, kinetics, and factors affecting the polymorphic transformation of nimodipine (NMD) and indomethacin (IMC) during high shear granulation. Granules containing active pharmaceutical ingredient, microcrystalline cellulose, and low-substituted hydroxypropylcellulose were prepared with ethanolic hydroxypropylcellulose solution, and the effects of independent process variables including impeller speed and granulating temperature were taken into consideration. Two polymorphs of the model drugs and granules were characterized by X-ray powder diffraction analysis and quantitatively determined by differential scanning calorimetry. A theoretical kinetic method of ten kinetic models was applied to analyze the polymorphic transformation of model drugs. The results obtained revealed that both the transformation of modification I to modification II of NMD and the transformation of the α form to the γ form of IMC followed a two-dimensional nuclei growth mechanism. The activation energy of transformation was calculated to be 7.933 and 56.09 kJ·mol(-1) from Arrhenius plot, respectively. Both the granulating temperature and the impeller speed affected the transformation rate of the drugs and, in particular, the high shear stress significantly accelerated the transformation process. By analyzing the growth mechanisms of granules in high-shear mixer, it was concluded that the polymorphic transformation of NMD and IMC took place in accordance with granule growth in a high-shear mixer.
AAPS PharmSciTech 05/2011; 12(2):610-9. · 1.43 Impact Factor
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ABSTRACT: The aim of this study was to develop cilostazol (CLT) nanocrystals intended to improve its dissolution rate and enhance its bioavailability.
In this study, CLT nanosuspension was prepared by the anti-solvent and high-pressure homogenization method. The effects of the production parameters, such as the stabilizer concentration, pressure and number of cycles, were investigated. Characterization of the product was performed by scanning electron microscopy (SEM), Nitrogen adsorption, differential scanning calorimetry (DSC), X-ray powder diffraction analysis (XRPD), X-ray Photoelectron Spectroscopy (XPS), particle size analysis and dissolution testing. Additionally, the comparison studies of oral bioavailability in beagle dogs of three type tables were performed.
The images of SEM showed a spherical smooth CLT powder, and Nitrogen adsorption test revealed spray dried powder were porous with high BET surface area compared with that of raw CLT. DSC and XRPD results demonstrated that the combination of preferred polymorph B and C of CLT were prepared successfully, the saturation solubility of the nanosized crystalline powder is about 5 fold greater than that of raw CLT, and the dissolution rate was enhanced 4 fold than that of raw CLT. The Cmax and AUC0-48h of CLT nanosized crystalline tablets were 2.1 fold and 1.9 fold, and 3.0 fold and 2.3 fold compared with those of the nanosized tablets and commercial tablets, respectively.
The anti-solvent-high-pressure homogenization technique was employed successfully to produce cilostazol nanosuspensions. The bioavailability of CLT tablets prepared using spray dried nanosized crystalline powder after oral administration to dogs was markedly increased compared with that produced by nanosized tablets and commercial tablets, because of its greater dissolution rate owing to its transition of the crystalline state to form C and form B, reduced particle size and porous structure with increased surface area.
Journal of pharmacy & pharmaceutical sciences: a publication of the Canadian Society for Pharmaceutical Sciences, Societe canadienne des sciences pharmaceutiques 01/2011; 14(2):196-214. · 1.65 Impact Factor
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ABSTRACT: This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
International journal of pharmaceutics 12/2010; · 2.96 Impact Factor
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ABSTRACT: A biodegradable porous starch foam (BPSF) was developed for the first time as a carrier in order to improve the dissolution and enhance the oral bioavailability of lovastatin - defined as a model poorly water soluble BCS type II drug. In this paper, BPSF was prepared by the solvent exchange method and characterized by scanning electron microscopy (SEM) and nitrogen adsorption/desorption analysis in order to perform the morphological and structural characterization of BPSF. Lovastatin was loaded by immersion/solvent evaporation into the BPSF which provided a stable hydrophilic matrix with a nano-porous structure. The solid state properties of the loaded BPSF samples were characterized by SEM, Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC). In vitro and in vivo drug release studies showed that when BPSF was used as a carrier it allowed immediate release of lovastatin and enhanced the dissolution rate in comparison with crystalline lovastatin and commercial capsules. These results provide important information about the mechanism of drug adsorption and release from BPSF as a carrier. Accordingly, BPSF has a promising future as a device for the oral delivery of poorly water soluble drugs.
International journal of pharmaceutics 10/2010; 403(1-2):162-9. · 2.96 Impact Factor
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ABSTRACT: The evaluation of N-trimethyl chitosan (TMC)-coated liposomes containing Coenzyme Q(10) as potential ophthalmic drug delivery system was carried out. Firstly, transcorneal permeation studies were conducted at 34°C using a side-by-side diffusion apparatus. The transport process of the fluorescent marker, rhodamine B, across the corneal epithelium was visualized with confocal laser scanning microscopy. Secondly, the human lens epithelial cells (HLECs) were cultured without or with Coenzyme Q(10) followed by addition of H(2)O(2). The cell viability and apoptosis were evaluated. The permeability coefficient for rhodamine B with TMC-coated liposomes increased more than two times in comparison with the value obtained for solution as control, from (0.42±0.018)×10(5)cms(-1) to (1.31±0.030)×10(5)cms(-1). Confocal laser scanning microscopy revealed that a TMC coating enhanced the transepithelial transport, dependent on the TMC concentration and contacting time. Coenzyme Q(10) elevated the cell viability and reduced the oxidative damage with the decreased percentage of apoptotic cells in a positive concentration-dependent manner. The ATP content of liposome-treated cells was increased about 2-fold compared with that of H(2)O(2)-treated cells. Together, our findings demonstrate that with the enhanced permeation effect of the TMC coating, Coenzyme Q(10)-loaded TMC-coated liposomes appear to be a promising ophthalmic drug delivery carrier with an efficacy in protecting HLECs against H(2)O(2)-induced oxidative damage.
International journal of pharmaceutics 10/2010; 403(1-2):219-29. · 2.96 Impact Factor
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ABSTRACT: Spherical mesocellular foam (MCF) with a continuous 3-D pore system was synthesized using Pluronic 123 triblock polymer (P123) as a surfactant coupled with cetyltrimethyl ammonium bromide (CTAB) as a co-surfactant. The feasibility of the prepared MCF nanoparticles for oral drug delivery was studied. A model drug, telmisartan (TEL), was loaded onto MCF via a procedure involving a combination of adsorption equilibrium and solvent evaporation. The drug-release rate and the drug loading efficiency of spherical MCF were compared with those of fibrous SBA-15. Investigations using nitrogen adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), wide-angle X-ray scattering (WXRS), differential scanning calorimetry (DSC) and HPLC demonstrated the successful incorporation of TEL into the MCF host. It is found that spherical MCF has a high drug loading efficiency up to 42.9% (drug weight/total weight) and higher than that of SBA-15 with a pore diameter of 6.5 nm. It is shown that a fast release rate of TEL was obtained from MCF compared with SBA-15 and pure crystalline TEL using enzyme-free simulated gastric fluid (pH 1.2) and intestinal fluid (pH 6.8). We believe that the present study will help in the design of oral drug delivery systems for the dissolution enhancement of water-insoluble drugs.
European journal of pharmaceutics and biopharmaceutics: official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V 09/2010; 76(1):17-23. · 3.15 Impact Factor
