Role of Co-Processed Superdisintegrants in Enhancing the Dissolution Rate of Nifedipine in Sublingual Tablets

The objective of the study was to formulate and optimize sublingual tablets (SLT) of Nifedipine for the treatment of angina and hypertension. The dissolution rate of Nifedipine was improved by co-processed superdisintegrants prepared by solvent evaporation technique. FTIR studies confirmed the absence of drug-excipients interactions. Cross carmellose sodium (CCS), sodium starch glycolate (SSG) and crospovidone (CPV) and their 1: 1 ratio coprocessed combinations were used as superdisintegrants. Six formulations (F1-F6) of SLTs were prepared by direct compression method using various concentrations of individual and co-processed superdisintegrant(s). The directly compressible blends have good flow characteristics. The formulated tablets were evaluated for hardness, thickness, weight variation, friability, wetting time; in-vitro dispersion time, water absorption ratio, drug content, disintegration time and the results were within USP limits. Formulation F6 (with co-processed SSG: CPV) showed shorter wetting time 22.21 sec and disintegration time of 1 min 45 sec, hence it was selected as the optimized formulation. The drug release from the SLTs follows first order release kinetics. Optimized formulation (F6) passes the test for stability as per ICH guidelines in final pack. Hence co-processed superdisintegrants are superior to individual ones.