Formulation, optimization and in vivo studies of oral controlled release tablets of Zidovudine

Abstract

The main aim of this research work was to develop a controlled release tablet of Zidovudine (AZT) by simplex lattice design. For this purpose three rate controlling polymers were studied i.e HPC, HPMC k100 and guar gum. Tablets  were  prepared  following  direct compression.  The  pre-­compression  and  post-­compression parameters were studied and were found to be within the limits of pharmacopoeia. The results of release profile suggested that the thick, viscous gel around the tablet contributed for controlled release. Statistical analysis was performed and found that, an appropriate amount of ternary blend of HPC, HPMC k100 and guar gum was crucial in controlling the release of AZT. Further formula optimization was done by using numerical optimization technique and the results suggested that the formula developed was reproducible. The results of in vivo studies showed that a C_max of 3.36 ± 0.84 (µcg/ml) was achieved in 4hr. The half-­life and mean residence time were found to be 6.26 ± 0.65hr and 11.30 ± 0.75 hr respectively indicating a prolonged release of Zidovudine.