Preparation, Evaluation and in vitro- in vivo Correlation (IVIVC) study of Lamivudine Loaded Microspheres.

A predictive IVIVC can empower in vitro dissolution as a surrogate for in vivo bioavailability/bio theraequivalence. IVIVCs can decrease regulatory burden by decreasing the number of bio-studies required in support of a drug product. The present study concerns the establishment of an invitro- in vivo correlation of prepared sustained release Lamivudine microspheres and compared with conventional Lamivudine tablet after administering orally to New Zealand white rabbit species. The correlation was established according to Drewe and Guitard basing on (degree A) Comparison of cumulative absorption profile and cumulative invitro dissolution profile, Invitro dissolution rate constant (K) Vs AUC (good linear correlation), Mean dissolution time versus mean residence time. The plasma drug concentration was estimated with the standard curve equation and compared with the standard tablet data. In comparison to the conventional dosage form, the T _max of all the formulations were increased from 1 hr to 4 hr confirming their sustained action. All the batches exhibited plasma profile within the therapeutic window of lamivudine. All formulated microspheres show identical pharmacological effect in comparison to standard lamivudine tablet. On the basis of the above plasma data analysis the formulation A2 was selected for invitro-invivo correlation study. First degree of correlation was established by comparing the invitro and invivo parameters of the same formulation. Parameters like dissolved fraction absorbed, DT vs MRT and T85% revealed a significant in vitro-in vivo correlation, which substantiate the success of the current study.