"Preparation, Characterization, and Evaluation of a Novel Co-Processed Excipient as a Directly Compressible Vehicle in Antihypertensive Tablet Formulation"

Abstract

Direct compression stands out as the preferred method for tablet preparation, with co-processing being extensively explored and commercially employed for creating directly compressible vehicles. This study aims to synthesize and characterize pregelatinized starch-polyvinylpyrrolidone (PGS-PVP) co-processed excipient and assess its suitability as a directly compressible vehicle for formulating tablets containing nifedipine, an anti-hypertensive drug. The PGS-PVP co-processed excipient was produced by gelatinizing potato starch in the presence of PVP and subsequently drying the resultant mass. Characterization involved determining melting point, solubility, water swelling index, pH, and micromeritic properties such as particle size, bulk density, tapped density, angle of repose, and compressibility index, followed by evaluation of its application in tablet formulations. The PGS-PVP co-processed excipient, comprising gelatinized potato starch (49 parts) and PVP (1 part), exhibited a crystalline, discrete, and free-flowing powder nature. It demonstrated insolubility in water, aqueous solutions with pH 1.2, 4.5, and 7.4, as well as various organic solvents. Remarkably, it displayed high water swelling capacity (280%). Alone and in blends with nifedipine, it showcased excellent to good flow properties. Tablets containing Nifedipine (60 mg) prepared via direct compression using PGS-PVP co-processed excipient as the directly compressible vehicle showed satisfactory quality attributes including drug content, hardness, friability, and disintegration time. All formulated tablets disintegrated rapidly within 3 minutes, achieving rapid dissolution of nifedipine, with 100 % dissolution attained within 20 minutes, meeting the official dissolution rate test specifications (IP/USP). Consequently, the PGS-PVP co-processed excipient developed in this investigation emerges as a promising vehicle for the preparation of nifedipine tablets.