Probing the effect of various lipids and polymer blends on clopidogrel encapsulated floating microcarriers.

Abstract

Clopidogrel (CLOP) is an antiplatelet drug with poor solubility in intestinal fluid, which limits its bioavailability after oral administration. Current study focuses on developing site-specific floating microcarriers of CLOP using solvent diffusion evaporation method (SDEM) for retaining the drug in the stomach, thus improving the solubility of drug for better absorption. SDEM was employed to formulate floating microcarriers using lipidic excipients, namely Gelucires (GL) to impart floating properties, in combination with ethyl cellulose as release retarding polymer. Prepared particles were 169 ± 6μm to 375 ± 13μm in size, whilst encapsulation efficiency was ranged from 39.6 ± 0.60% to 96.50 ± 3.50%. Electron micrographs depicted discrete spherical microcarriers with porous structure, which amplified with increasing HLB value of GL and concentration of Eudragit E100. FTIR study confirmed absence of major drug polymer interactions while DSC and XRD studies revealed the presence of non-crystalline nature of drug in all formulations. Drug release at pH1.2 enhanced more than 2-folds with increasing HLB value with 32% cumulative drug release for GL 43/01 and 69% for GL 50/13. More interestingly, adding various proportions of Eudragit E100 to GL 43/01 based formulations resulted in increased drug release as high as 71%. In all formulations, the drug release followed diffusion dependent process. It is envisaged that this formulation strategy for CLOP is promising and could possibly be tested in future for its in vivo performance. Graphical abstract Lipid based floating microcarriers of clopidogrel.