PREPARATION AND CHARACTERIZATION OF PRAGELATINIZED CASSAVA STARCH PHTHALATE AS A PH-SENSITIVE POLYMER FOR ENTERIC COATED TABLET FORMULATION

摘要

Modification of starch is a process which intended to expand utilization of starch as pharmaceutical excipients. In the present study, pragelatinized cassava starch phthalate (PCSPh) was produced by a process of pregelatinization of cassava starch and then esterification using phathlic anhydride in basic aqueous medium. The obtained PCSPh was characterized, including degree of substitution (DS), functional group, thermal properties and solubility. PCSPh was then utilized as coating material for tablet using ketoprofen as drug model. Core tablets were prepared by wet granulation process and then compressed into white round-biconvex tablets. Subsequently, core tablets were coated with coating solution, containing PCSPh 5%. The results showed that PCSPh possess DS of 0.054; carbonyl ester was detected at infrared wavenumber of 1716.70 cm-1; melting temperature at 156.52 – 164.48 oC and lower solubility in acid medium rather than in base medium. The coated tablets possessed good appearance, hardness and friability. Moreover, coated tablets were undisintegrated in acid medium for 1 hour, and the dissolution of ketoprofen from coated tablets were less than 10% in acid medium (pH 1.2). The results revealed that PCSPh was prospective to be applied as a enteric polymer excipient for enteric-coated tablets.