Formulation and Evaluation of Candesartan Cilexetil Fast Dissolving Tablets using Inclusion Complexes

Abstract

In the present investigation, an attempt was made to improve the dissolution rate and bioavailability by inclusion complexes using Candesartan cilexetil and s-cyclodextrin. Solid dispersions were prepared by physical mixing, co-evaporation and kneading methods using Candesartan Cilexetil and s-cyclodextrin in 1:1 ratio. The complexes were evaluated for phase solubility, drug content and drug release. The drug release study was carried out using phosphate buffer pH 6.8 as dissolution medium. The inclusion complexes prepared by solvent evaporation method showed rapid drug release when compared to physical mixing and kneading methods. The optimized complexes were further formulated as fast dissolving tablets using superdisintegrants like sodium starch glycolate (SSG) and croscarmellose sodium (CCS) in varying ratios by direct compression method. Various pre and post compression parameters were evaluated for the granules and all were found to be in specified Indian Pharmacoepial limits. Dissolution profiles showed that the formulation C6 with 15% w/w of CCS as superdisintegrant showed rapid drug release when compared to other formulations. FTIR and DSC analysis of pure drug and optimized formulation revealed no major interactions between the drug and polymers. Model independent techniques including similarity factor, dissimilarity factor and dissolution efficiency were applied for comparison of dissolution profiles. Thus it was concluded that fast dissolving tablets of Candesartan cilexetil showed enhanced dissolution rate.