Development and application of atr-ftir spectroscopy for mixture homogeneity in pharmaceutical application

Modified release formulation, however, the performance of dosage form not only depends on active pharmaceutical ingredient (API) distribution, but also excipient is a fundamental key on this system. The objective of this research was to apply a simple and fast method on monitoring the API-excipient homogeneity using attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy in a gastro-floating formulation. Gastro-floating formulation comprising metformin HCl, polymers, and effervescent components was blended in a cube mixer at several revolutions. At predetermined times, 50 mg of mixture was withdrawn in three different spots. ATR FTIR spectra acquisition was carried out from 4000 to 650 cm^-1 at resolution of 2 cm^-1 with 32 iterations. In order to minimize error, each sample was analyzed quadruplicates. The homogeneity was depicted by a relative standard deviation of each sampling time. Specific vibration peaks that had a good resolution and low interference each other were selected to determine the response value. Vibration peaks at 3365, 3148 and 937 cm^-1;1730 and 1051 cm^-1; and 1276 cm^-1 were assigned as metformin HCl, polymers, and sodium bicarbonate quantification peaks, respectively. The RSD of API and excipients showed a quadratic curve. Thereby, it confirmed that the blending system followed a random mixing process. The ATR-FTIR technique was successfully applied in the monitoring of API-excipient distribution in the gastrofloating formulation. The homogeneity of metformin HCl gastro-floating formulation was achieved by mixing of 15 min with 25 rpm with lowest RSD of API and excipients.