Development and validation of a UV-spectrophotometric method for determination of an ACE inhibitor in pharmaceutical formulations.

Introduction: Fosinopril sodium, an angiotensin-converting enzyme inhibitor, is a widely prescribed antihypertensive agent and one of the leading drugs approved for use in hypertension management. Despite its clinical relevance, no UV-spectrophotometric methods have been previously reported for the analysis of fosinopril sodium in simulated salivary fluid (SSF, pH 6.8) and simulated gastric fluid (SGF, pH 1.2). However, researchers favor UV-spectrophotometry due to its versatility, simplicity, and efficiency in drug analysis. Aim: The aim of this study was to develop and validate a simple, rapid, and cost-effective UV-spectrophotometric method for analyzing fosinopril sodium in both experimental and commercial dosage forms, as well as in novel drug delivery systems. Materials and methods: This study presents the development of a UV-spectrophotometric method for quantifying fosinopril sodium in enzyme-free SSF and SGF media and its validation. Results: Maximum absorbance is observed at 209 nm in SSF and 207 nm in SGF. The technique demonstrates linearity in the range of 2.5–20 μg/mL, with a limit of detection and limit of quantification of 0.0438 μg/mL and 0.133 μg/mL in SSF, and 0.0714 μg/mL and 0.216 μg/mL in SGF, respectively. Analytical recovery is 100.1% in SSF and 99.9% in SGF, with RSD values of 0.373% in SSF and 0.203% in SGF, indicating high precision and accuracy. Conclusion: These results demonstrate that the developed and validated method is suitable for the routine quantitative determination of fosinopril sodium in experimental and commercial pharmaceutical formulations.