Formulation and Evaluation of Release-Retardant Matrix Tablets of Diclofenac Sodium
Sunita DAHIYA*^,o
* Rajiv Academy for Pharmacy, Department of Pharmaceutics, Mathura - 281 001 (UP), INDIA

^oCorresponding Author

Summary

The objective of the present study was to develop release-retardant matrix tablets of diclofenac sodium by wet granulation technique using hydroxypropylmethylcellulose, sodium carboxymethylcellulose, sodium alginate and cetostearyl alcohol. Before tablet preparation, the granules were evaluated for angle of repose, bulk density, compressibility index and drug content. All the granulations showed satisfactory flow properties, compressibility and drug content. The tablets were evaluated for thickness, diameter, diameter/height ratio, hardness, weight variation, drug content, and in vitro drug release. The dissolution data was further characterized by model-independent parameters such as time to release 25 and 90% drug (t25% and t90% respectively), dissolution efficiency at 720 min (DE720), and
mean dissolution time (MDT). The tablet formulations showed acceptable pharmacotechnical properties and complied with pharmacopeial specifications for tested parameters. All the formulations showed extended drug release up to 12 h. However, the formulation prepared with drug: hydroxypropylmethylcellulose (1:4) using ethanol as granulating agent (F10) extended the drug release up to 24 h with initial burst effect, and was further modified using hydrophobic granulating agent ethyl cellulose. F11 significantly reduced the burst release, extended the drug release up to 24 h followed by zero order kinetics (r² = 0.9872) and emerged as the most successful tablet formulation.

Key Words :
Diclofenac sodium, matrix tablet, sustained release, wet granulation, in vitro dissolution, model-dependent parameters, model-independent parameters.