Formulation and Evaluation of ethyl cellulose microspheres containing diclofenac sodium

Abstract

Diclofenac sodium belongs to a class of drugs known as non-steroidal anti-inflammatory drugs (NSAIDs). This medication is used to relieve joint pain from arthritis. It has shorter half life (2hr). It undergoes extensive first pass metabolism. Frequent dosing is required in case of conventional dosage form. The objective of present study was to develop ethyl cellulose-based sustained release diclofenac sodium microspheres to reduce the dosing frequency to achieve targeted drug delivery system. The diclofenac sodium-loaded ethyl cellulose microspheres were formulated by emulsification technique and the physicochemical properties of the formulations were characterized. Compatibility studies were carried out using FTIR studies. The percentage drug content was studied in three different pH media (pH 1.2, pH 6.8 and pH 8.0). The entrapment efficiency of these microspheres was between 36% and 80.95%. The obtained microspheres showed good flow properties, which were evaluated in terms of angle of repose (15.27 – 20.30), bulk and tapped densities (0.34-0.39 and 0.37-0.48, respectively), Carr indices and Hausner ratio (20-45 and 1.03-1.80, respectively). Particle size and percentage drug content depended on the nature and content of polymer used. In formulation (F) first drug and ethyl cellulose were use in 1:1, 1:2 and 1:3 ratios. As the concentration of polymer increases the drug encapsulation in microsphere were increasing. Formulation F3 was found best formulation. Thus, overall study reveals that prepared microspheres of diclofenac sodium by using ethyl cellulose using binary organic mixture as solvent at different ratios to enhances the percentage drug content and flow properties.