Ester Prodrug of 5-Aminosalicylic Acid for Colon Specific Drug Delivery: Synthesis, Kinetics, Hydrolysis and Stabilities

Acrylic type polymeric systems having degradable ester bonds linked to the 5-aminosalicylic acid (5-ASA), were synthesized and evaluated for colon targeted drug delivery. The obtained prodrug was characterized by FTIR,HNMR,Melting point and Rf value.In vitro drug release study was conducted at pH 1.2,7.4 and in rat fecal matter. Drug release in rat fecal matter at pH 7.4 was found to be most satisfactory. A burst release of 41.65% was observed in the first two hours followed by a sustained release over a period of 12 hours. A maximum of 92.46% of the drug was released from the prodrug and the time taken for 50% drug release (t50) was found to be nearly 3 hours. The best linearity for the prodrug was found in Higuchi’s equation, where r value was 0.9852, indicating the release of drug from prodrug as square root of time dependent process based on Fickian diffusion.The result suggest that these systems could be useful for preparation of a controlled release formulation of 5-aminosalicylic acid to target colon.