Abstract
Studies In The Preparation Of Diclofenac Sodium Microspheres By Emulsion Solvent Evaporation Technique Using Response Surface Analysis
The objective of this investigation was to study the factors influencing the characteristics of modified release microspheres of diclofenac sodium. A series of batches were prepared by solvent evaporation technique using ethyl cellulose as a matrixing agent. The study revealed that for obtaining discrete microspheres optimum quantity of Span 60, a surfactant, is necessary. The stirring speed, polymer to drug ratio, concentration of ethyl cellulose solution and type of solvent were found to influence the in vitro drug release from the microspheres. Sigma PlotR software was used to generate interpolated values of the percent drug dissolved in 360 min (Y360). The response surface plot showed that the effect of polymer to drug ratio is more predominant than the concentration of ethyl cellulose solution. The argument is further supported by modeling the data using regression analysis. The kinetics of drug release was studied using non-liner regression analysis in EXCELR spreadsheet. The Korsmeyer and Peppas model fitted well to the data. The drug was released by non-Fickian diffusion. The performance of the formulated product is compared with a commercial product. Comparison showed that the effect of the formulated product may last for longer time duration. The microspheres exhibited poor compressional characteristics.