Current Issue : April - June Volume : 2015 Issue Number : 2 Articles : 3 Articles
Cytomegalovirus retinitis is disease condition of posterior part of eye. Conventional delivery systems often result in poor bioavailability and therapeutic response because high tear fluids turn over and dynamics cause rapid elimination of the drug from the eyes. So, to overcome bioavailability problems, ophthalmic in-situ gels were developed. From a manufacturing point of view, the production of such devices is less complex and thus lowers the investment and manufacturing cost. The objective of present study was to prepare pH-dependent in-situ gel system of ganciclovir and optimize the effect of formulation variables i.e. concentration of carbopol 940 and HPMC E50LV. The experimental design selected was 32 full factorial designs using these two variables. Viscosity and drug release after 7 hr were evaluated as response variables. It was observed that concentration of polymers directly affect the viscosity and drug release profile. Mathematical models were generated for each response parameters to predict their values at selected levels of formulation variables. The effect of the variables and behavior of the system was studied using response surface plots. The optimized formulation showed viscosity of 983.860 cp and in-vitro permeation of 95.15%. The results of this study revealed that the in-situ gel prepared with 0.4% w/v concentration of carbopol 940 and 1.5% w/v concentration of HPMC E50LV showed optimum transscleral permeation....
Dendrimers are known for their three dimensional, monodispersed, highly branched, macromolecular nano-scopic architecture with number of reactive end groups. Dendrimers have been reported to act as solubilizing agents to host both hydrophilic and hydrophobic drugs. The present study was performed to investigate the effect of poly (propylene) imine dendrimers (5.0G) mediated solubility enhancements of hydrophobe. The solubility of prednisolone was enhanced at pH 7.4. The drug-dendrimer complex followed 1:1 stoichiometry (AL type of curve) and was characterized for stability of complex and thermodynamic properties. Thermodynamic properties were utilized to elucidate the mechanism behind dendrimer mediated solubility enhancement. The data suggested that hydrophobic and electrostatic interactions were responsible for solubility enhancement. Conclusively, PPI dendrimers were found useful in solubility enhancement of prednisolone and their solubilization ability was clearly regulated by pH and chemical nature of the drug....
The main aim of this study was to evaluate the starch acetate as a coat for controlled release microcapsules of glimepiride. Starch acetate based microcapsules were prepared by an emulsion solvent evaporation method employing different core: coat ratios. From in-vitro release studies, it was found that glimepiride release from the microcapsules was slow and spread over a period of 24 h and depended on core: coat ratio, wall thickness and size of microcapsules. Starch acetate was found suitable as microencapsulating agent. Starch acetate coated microcapsules exhibited good controlled release characteristics and were found suitable for oral controlled release of glimepiride over 24 h....
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