MICROENCAPSULATION OF PIROXICAM USING PH SENSITIVE POLYMERS
Esmat E. Zein, Ahmed A. Donia and Sania El-kayad*
Different techniques are utilized to reduce gastrointestinal side effects of non-steroidal anti-inflammatory drugs (NSAIDs) including microencapsulation by pH sensitive polymers. Enteric coated piroxicam microspheres were prepared to reduce its side effects. Microspheres were prepared using emulsion solvent evaporation method using Eudragit L100 and Eudragit S100 as pH sensitive polymers for enteric coating of piroxicam. Entrapment efficiency and percent yield was measured for the prepared formulations and it was found that it depends on polymer type as well as drug polymer ratio. IR analysis was used to predict any interaction between drug and the used polymers. It revealed presence of intermolecular hydrogen bonding between piroxicam and Eudragit polymers. In vitro dissolution test was carried out using three different PH media (1.2, 6.8 and 7.4) to determine release of drug at different pH values. All formulations showed burst release at PH 1.2 but Eudragit L100 polymer containing formulations showed the highest initial rapid burst release. Formula B2 was found to be the best formula as it has only 6% burst release within 2 hrs at pH 1.2.
Keywords: Eudragit L100 and Eudragit S100
[Full Text Article]