Enhancement of Solubility of Nimesulide in the Presence of Polymer with Milling Technique

Poor aqueous solubility of drugs generally leads to low dissolution rates, poor therapeutic efficiency and low bioavailability. The main aim of this study was to produce physical dispersions of Nimesulide with polymers Eudragit EPO and Mannitol and then subject it for milling, to analyze the role played by different type and concentrations of polymers and the mechanism of impact and attrition milling in enhancing the solubility of the pure drug and its physical dispersions. Using ball milling technique the physical dispersions of Nimesulide with the polymers, prepared in the ratios of 1:1, 1:3, 1:5 were subjected to size reduction for two different time intervals of 30 min and 90 min, individually. Particle size, flow property and solubility of the milled dispersions were assessed and compared with the non milled dispersions and the pure drug. The milled dispersions were fabricated into tablets and the evaluation parameters like weight variation, disintegration time, hardness and dissolution studies were conducted on the prepared tablets. In order to observe the changes in the solid state at powder level and molecular level, the formulations were characterized by Fourier Transform Infra Red Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and X-Ray Diffractometer (XRD). The results obtained show that the physical dispersions prepared by milling with Mannitol helped in increasing the dissolution rate of the drug.