ABSTRACT:
The current study concern with the evaluation of natural gum moi as noble sustain release rate controlling materials in microsphere formulation prepared by solvent evaporation technique using lamivudine as the model drug. Microspheres were evaluated for various parameters such as yield percentage, particle size analysis, sphericity measurement, drug entrapment efficiency, loose surface crystal study, in vitro drug release profile and release kinetics study. Effect of drug: gum ratio (1:6, 1:10 w/w with respect to drug weight) on in vitro drug release profile was investigated The rate limiting capacity of moi gum was compared with guar gum as control by keeping all the parameters constant. The gum produced microspheres have satisfactory size (24- 32µm) and acceptable morphological properties. Microspheres of moi gum exhibit sustained action beyond 10 hr in comparison to guar gum but the combination of both the gum in 1:1 ratio demonstrate an additional sustained action. Drug release from the F1, F2, F4 and F6 seems to best fit to Higuchi square root kinetics indicating the diffusion controlled release where as the F3 follows zero order kinetic and f5 shows korsemeyer-peppas model. The release mechanism was found fickian for all the formulations as polymer matrix was used as rate retarding material. It was concluded that the gum possesses substantial rate controlling properties with the combination of guar gum and could be used for sustained drug delivery.