Purpose: The objective of the study was to develop microspheres of Losartan potassium as controlled drug delivery system by using various polymer (HPMC and Ethylcellulose), evaluating the relationship and influence of different content levels of HPMC, and Ethylcellulose, in order to achieve a zero order release of Losartan potassium.
Approach: Microspheres were prepared by solvent evaporation process. Release kinetics was evaluated by using United States Pharmacopoeia (USP) type I dissolution apparatus. The release mechanism of microspheres loaded with Losartan potassium was determined by fitting the data in Korsmeryer peppas equation. The regression coefficient values for Peppas model was found to be high, indicating adequate fitting. The 'n' value was ranged from 0.548 to 0.963 indicating Non Fickian diffusion for all the formulations. Optimization was performed by using desirability function. To validate the model, the optimized formula was subjected to in vitro characterization.
Findings: Release kinetics of Losartan potassium from these microspheres was principally regulated by HPMC K4M and Ethylcellulose. Percentage yield, entrapment efficiency and particle size of optimized formula was found to be 91.42%, 68.01% and 310μm. Formulation (F1) release at the end of 12 hours of dissolution studies was found to be 79.81%.
Conclusion: It can be concluded that Losartan potassium loaded microspheres could be successfully formulated by using HPMC 4KM and Ethylcellulose by solvent evaporation method to obtain maximum percentage yield, entrapment efficiency, desired particle size.
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