Formulation Development and in vitro Evaluation of Drug Release Kinetics from Sustained Release Aceclofenac Matrix Tablets using Hydroxypropyl Methyl Cellulose

Abstract

The objective of the present study was to develop a once-daily sustained release matrix tablet of
Aceclofenac using hydroxypropyl methyl cellulose (Methocel K 100M CR) as release controlling factor and to
evaluate drug release parameters as per various release kinetic models. The tablets were prepared by direct
compression method. The powder blends were evaluated for angle of repose, loose bulk density, tapped bulk density,
compressibility index, total porosity and drug content etc. The tablets were subjected to thickness, weight variation
test, drug content, hardness, friability and in vitro release studies. The in vitro dissolution study was carried out for 24
hours using United States Pharmacopoeia (USP) 22 paddle-type dissolution apparatus in phosphate buffer (pH 7.4).
The powder blends showed satisfactory flow properties, compressibility index and drug content etc. All the tablet
formulations showed acceptable pharmacotechnical properties and complied with pharmacopoeial specifications. The
results of dissolution studies indicated that the formulation F-3 (40% Methocel K100M CR of total weight of tablet)
could extend the drug release up to 24 hours and the total release pattern was very close to the theoretical release
profile. By comparing the dissolution profiles with the originator brand of Arrestin SR, the formulation F-3 exhibited
drug release profile like originator brand. From this study, a decrease in release kinetics of the drug was observed by
increasing the polymer concentration. Kinetic modeling of in vitro dissolution profiles revealed the drug release
mechanism ranges from diffusion controlled or Fickian transport to anomalous type or non-Fickian transport, which
was only dependent on the type and amount of polymer used. The drug release followed both diffusion and erosion
mechanism in all cases. The drug release from the formulation (F-3) was satisfactory after 3 months storage in 400C
and 75% RH. Besides, this study explored both of the optimum concentration and effect of polymer(s) on
Aceclofenac release pattern from the tablet matrix for 24 hour period. The matrix tablet of Aceclofenac using HPMC
with molecular weight of K100M controlled the drug release effectively for 24 hours; hence the formulation can be
considered as a once daily sustained release tablet of Aceclofenac in order to improve patient compliance.