Method of Starch Acetylation and Use of Acetylated Starch as Polymer in Pharmaceutical Formulations

Abstract

Starch is used as a key polymer in pharmaceutical industries since long back for various purposes such as binder, disintegrating agent, bulking agent, film former and many more. But as per the purpose of dosage forms it’s used get changed. Currently scientists are more focused on controlled and sustained release dosage forms. Since, native starch does not meet up the demand of controlled or sustained release, so there is need of modifying the polymer as per dosage form requirement. Modification of starch can be done by physical, chemical, enzymatic, and genetic method. Among all, the current article is focusing on chemical modification of starch, especially the acetylation. Acetylation of starch can be done using different acetylating agent such as acetic anhydride (AA), and glacial acetic acid etc. and sodium hydroxide (NaOH), pyridine and sulphuric acid etc as a catalyst. The native structure of starch can be less efficient, since its functional properties are less stable to process condition such as high temperature, shear stress and exposure to acidic media, which decreases its use in industrial application. Acetylated starches facilitate higher stability and resistance to retrogradation or crystallization, enhanced granular size, swelling power, and water absorption capacity, which provides good flow and compression properties. It reduces the pasting temperature and solubility. It makes the acetylated starch as a good candidate for customizing the overall performance of native starch, which may be used as the controlled release or sustained release polymer in pharmaceutical dosage form.