Preparation and Evaluation of Captopril Oral Floating Controlled Release Formulations

Aim: Dosing frequency is a major hurdle in geriatrics with frequent drug administration. In such cases, oral controlled release floating formulations are helpful which causes reduction in dosing frequency and fluctuation of drug levels in plasma. The main aim of the current research was to prepare Captopril floating controlled release formulations in order to achieve extended gastric retention in the upper GIT.

Methodology: Captopril tablets were prepared using different concentrations of poly ethylene oxide water soluble resin (PEO WSR) 303 (5% to 30%) by direct compression technique. Captopril formulations CSP1 and CSP6 were formulated using PEO WSR 303. Pre and post compression parameters were evaluated. Dissolution studies were performed for the prepared tablets using 0.1N hydrochloric acid as dissolution medium.

Results: The dissolution studies showed controlled drug release up to 12h. The formulation CSP5 prepared using 25% w/w of PEO WSR 303 showed maximum drug release of 97.97% at 12h. Almost similar drug release profile was also observed for CSP6 which was prepared using 30%w/w PEO WSR 303. These two formulations were further added with various concentrations of sodium bicarbonate (5% to 15%) and citric acid (2.5% to 10%) which enhanced floating of drug in Gastro intestinal tract (GIT). Formulation CSP8 containing 10% of sodium bicarbonate with 25% PEO WSR 303 showed less buoyancy lag time and prolonged drug release. Formulation CSP15 showed very less buoyancy lag time of 5sec. Characterization studies like Fourier Transform Infra Red spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) were also carried out.

Conclusion: The prepared Captopril floating tablets could be an alternative formulation for prolonged drug release.