Automated drug dissolution monitor that uses a UV-visible diode array spectrophotometer

A method for performing multicomponent analysis in drug dissolution testing without chromatographic separation is presented. Aliquots from dissolution vessels are automatically transferred to a UV-visible diode array spectrophotometer, spectra are measured, and the aliquots are returned to the testing vessels. A full-spectrum calibration method based on principal-component regression is used to simultaneously determine the concentrations of active ingredients and to account for interferences due to excipients in a tablet formulation. The system was evaluated with two commercial pharmaceutical formularies; the first contained pseudoephedrine hydrochloride and chlorpheniramine maleate, whereas the second was a mixture of phenylpropanolamine hydrochloride and chlorpheniramine maleate. The selections of standard mixtures for calibration and validation were based on a factorial design.