Formulation and evaluation of Abacavir microspheres

The objective of present study was to encapsulate the anti-retroviral drug in various polymers in order to provide the sustained release and to minimize or reduce the dose dependent side effects as well as to improve the patient compliance. Abacavir sulphate microspheres were prepared by w/o emulsification solvent evaporation method using different polymers viz. sodium alginate and gelatin. The prepared microspheres were characterized for drug entrapment efficiency, muco-adhesion test, particle size analysis, surface morphology and in-vitro drug release study. The in-vitro release studies were performed using pH 1.2 Hcl and pH 7.4 phosphate buffer and drug release is evaluated. Morphology of microspheres was characterized by using Scanning Electron Microscopy (SEM). The prepared microspheres were small, discrete, free flowing and spherical in shape. The mean diameter of microspheres was between 21.00±1.96 to 32.43±2.19 μm for different formulations. The drug loaded microspheres showed 40-65% and 45-50% of entrapment for sodium alginate and gelatin microspheres respectively. Fourier Transform- Infra Red (FT-IR) was performed to evaluate interaction between drug and polymer. The prepared microspheres exhibited prolonged drug release (10h) as the concentration of sodium alginate increased, the muco-adhesion is also increased as the sodium alginate concentration increases and the drug release rate was decreased at higher concentration of gelatin.