Synthesis of sodium alginate grafted stearate acid (NaAlg-g-St) and evaluation of the polymer as drug release controlling matrix

Sodium alginate grafted stearic acid (NaAlg-g-St) was synthesized via the reaction of stearic acid and sodium alginate (NaAlg) in the presence of diisopropylcarbodiimid (DIC) under the solvent free condition. Sustained release matrix tablets of indomethacin (IM) were developed by employing sodium alginate or the new synthesized polymer. The drug dissolution test and other physicochemical properties were evaluated for each formulation. The results of this study showed that sodium alginate grafted stearic acid, has a good effect on the sustained releasing feature of the tablets and causes the drug to be released gradually; and probably, causes less side effects and more compliance in patients. In the physicochemical tests, the usage of NaAlg or the NaAlg-g-St was not effective on the tablet’s hardness but in other tests made a significant change statistically.