Pre-formulation studies and Evaluation parameters of Bioadhesive Gel Incorporated Metronidazole Loaded Microspheres

Abstract

Metronidazole is an antiprotozoal and antibacterial medication used mainly in the treatment of anaerobic bacteria. The preformulation studies were carried out in terms of tests for identification (physical appearance, melting point and IR spectra), solubility profile and quantitative estimation of drug. The absorption maxima (λ_max) of drug were determined by UV visible double beam spectrophotometer (Shimadzu-1800). Accurately weighed 10 mg of metronidazole dissolved in 10ml of phosphate buffer (pH 6.8) to prepare a stock solution of 1000 μg/ml concentration. Drug polymer interactions were studied by FTIR spectroscopy. The spectra were recorded for pure drug and drug loaded microspheres using FTIR. The solubility of metronidazole was tested in various solvents. A definite quantity (10mg) of drug was dissolved in 100ml of each investigated solvents at room temperature. Microspheres were prepared by emulsion cross linking method. Particle size was determined by using a Zetasizer nano series 90 (Malvern instruments, UK). The prepared microspheres were collected and weight. The entrapment drug concentration was determined by centrifugation of the microspheres. The microspheres were centrifuged for 20 min at 1000 rpm. The sample the scanning electron microscopy (SEM) analysis was prepared by sprinkling the microspheres on one side of the double adhesive stub. Microspheres, equivalent to 10 mg of Metronidazole, were accurately weighed and transferred to 250 ml conical flask containing 100 ml phosphate buffer (pH 6.8). The flask was kept in an incubator at 37 °C, 1 ml samples withdrawn at regular intervals and, after suitable dilution, the amount of drug released was determined using a spectrophotometer at 227.72 nm.

Keywords: Metronidazole, preformulation, Microspheres, drug released and SEM