Background: Nifedipine is a potential therapeutic agent for the treatment of cardiovascular
disturbances, although it suffers from short half-life (t1/2, 2 hr).
Objective: To address the problem, we first prepared nifedipine loaded sustained release microsponges
and then formulated tablets for effective clinical application and patient compliance.
Method: Preparations of microsponges were carried out using different compositions of nifedipine and
polymer (1:1, 1:2 and 1:3 % molar ratio) using emulsion solvent diffusion technique.
Results: The microsponges with molar ratio 1:3 (formulation code: MF-3) found optimized as revealed
by analyzing surface morphology, better powder flow properties (angle of repose; 28.80 ± 0.9,
Hausner ratio 1.15 ± 0.2, % compressibility 15.28 ± 0.5% and higher % drug content (80 ± 1.9 %).
Different batches of tablets were then formulated incorporating MF-3 microsponges and different proportions
(10-50 %) of microcrystalline cellulose and starch as additives. Among tablet formulations,
batch composed of 48% of MF-3, 30% of MCC, 20 % of starch and 2 % of talc (TF-33), showed
92.73 ± 2.19 % drug release during 24 hr in vitro release study in comparison to other batches including
commercial formulation which was found to be released completely in 20 hr. Further, stability
analysis revealed good drug retention of loaded nifedipine as well as consistent in vitro release pattern
over a period of 90 days at 40°C and 75% RH.
Conclusion: The microsponge tablet delivery system was found to be superior concerning the therapeutic
advantage as well as manufacturing feasibility of nifedipine.