Formulation and Assessment of Candesartan Immediate Release Tablet by Direct Compression Method

Abstract

The present work is aimed at developing and evaluating an immediate-release (IR) tablet of Candesartan Cilexetil using direct compression, with the objective of enhancing its dissolution rate and oral bioavailability, as the drug is poorly soluble in water. Candesartan belongs to the Biopharmaceutical Classification System (BCS) class II, showing high permeability but limited solubility, making dissolution the rate-controlling step for absorption. This limitation is particularly important in hypertension therapy, where a rapid onset of action is crucial.

The formulation approach employed a combination of natural superdisintegrant (Isapghula husk) and synthetic superdisintegrant (Sodium Starch Glycolate) in varying ratios, along with conventional excipients such as Avicel PH 102, lactose monohydrate, talc, and magnesium stearate. Preformulation studies, including melting point determination, UV spectroscopic analysis, FTIR compatibility testing, and solubility assessment, confirmed the purity and stability of the drug–excipient mixture.

Evaluation of post-compression parameters involved determination of hardness, friability, disintegration time, drug content uniformity, and in vitro release behaviour. Among all prepared batches, formulation F5 was found to be superior, as it showed the shortest disintegration time and maximum drug release. The release profile was best explained by first-order and Higuchi models, suggesting that the drug release followed a diffusion-controlled mechanism.

Overall, this investigation demonstrates that direct compression is a simple, reliable, and scalable technique for producing immediate-release Candesartan tablets, with the potential to improve patient compliance and therapeutic efficacy in the treatment of hypertension.