Tablets containing metoprolol succinate and Compritol®888ATO in the ratio of 1:2 yielded the desired sustained release profile in phosphate buffer pH 6.8 when evaluated using USP type II paddle
apparatus and was selected as the optimized formulation. Robustness of optimized formulation was assessed by studying the effect of factors like varying source of metoprolol succinate and
Compritol®888ATO, compression force and hydroalcoholic dissolution medium on the release profile. No significant difference (P >0.05) in release profile was observed when metoprolol succinate
from three different sources and Compritol®888ATO from two different batches were used.
