Simultaneous acquisition of the dissolution curves of two active ingredients in a binary pharmaceutical association, employing an on-line circulation system and chemometrics-assistance.

The association of an on-line circulation system with a chemometrics-assisted UV detection strategy is described as a useful system to continuously monitor the dissolution of a pharmaceutical preparation containing two active ingredients, and as a tool for the simultaneous determination of the dissolution curves and dissolution profiles of the latter. Multivariate curve resolution with alternating least squares (MCR-ALS) was used as the chemometric tool to quantitate the analytes, while the hydrochlorothiazide-bisoprolol fumarate (HCT-BIS) association was employed as a model for method development. The experiments were carried out with a dissolution tester configured as apparatus II (paddles), under USP 32 official conditions. The suitability of the calibration procedure for quantitating the dissolved drugs was assessed according to ICH guidelines, with regards to linearity in the working range, specificity, accuracy and precision. Figures of merit, including limits of detection and quantitation were also determined, as well as the method's robustness with regards to detection wavelength range. The system was able to consistently provide very reproducible dissolution curves of commercial tablets, which were statistically similar to those furnished by a manual sampling technique, followed by HPLC analysis. To demonstrate the usefulness of the proposed system, the dissolution profiles of different lots of HCT-BIS tablets were acquired and three of them were conveniently compared at a 31 data point level, employing the f(1) and f(2) ("difference" and "similarity") indexes. Use of multiple data points for comparison ensured reliability of the results.