Abstract

IMPROVEMENT OF BIOAVAILABILITY OF A DRUG BELONGING TO BIOPHARMACEUTICAL CLASSIFICATION SYSTEM CLASS II

Moataz Farid, Alyah Al Atwi, Ebtihal Al Qahtani, Lama Allam and Lilian Saher*

ABSTRACT

Piroxicam is a non-steroidal anti-inflammatory drug belonging to biopharmaceutical classification system (BCS) class II which has high permeability and low solubility. Hence, its pharmacological effect is affected by its low water solubility. For BCS class II drugs, the dissolution rate is the rate limiting step for drug absorption. The aim of this research is to increase the solubility and dissolution rate of piroxicam to improve its absorption and bioavailability. Piroxicam was recrystallized into spherical agglomerates with different polymers (Polyethylene glycol 4000 and ß-cyclodextrin) at three different concentrations (0.05, 0.1 and 0.5 % w/v) using neutralization technique. Piroxicam agglomerates were evaluated for solubility, yield, drug content, dissolution rate and kinetic data analysis. Piroxicam agglomerates images were taken using optical as well as electron microscope. The results indicated that piroxicam spherical agglomerates containing moderate concentration level of polymer (0.1 % w/v) showed highest solubility and dissolution rate enhancement compared to pure piroxicam powder. The image taken confirmed that the produced agglomerates were spherical in shape. The anti-nociceptive effect of the best formulae of both polymers (showing the highest dissolution in simulated intestinal fluid) was assessed in mice using acetic acid induced abdominal writhing in comparison to pure drug. The selected formulae showed significantly higher bioavailability indicated by the higher analgesic activity in comparison to the pure drug and the control.

Keywords: Piroxicam, Spherical agglomerates, PEG4000, ß-cyclodextrin, Neutralization Technique.