Synthesis of starch-based drug carrier for the control/release of estrone hormone

The objective of this study was to provide new synthetic route to prepare starch as a potential carrier for controlled release of drugs. A starch was modified with bromoacetyl bromide in order to provide more reactive sites for coupling of bioactive estrone and a suitable spacer between the drug carrier and the hormone. The degree of substitution (D.S.) per anhydroglucose (AHG) unit was calculated from the bromine content and ranged from 0.11 to 2.29, depending on the ratio of bromoacetyl bromide to starch. The starch-estrone conjugate was then synthesized by reacting bromoacetylated starch with the sodium salt of estrone. The structures of bromoacetylated starch and starch-estrone conjugate were determined by means of FTIR,1H NMR,13C NMR and UV. Additionally, X-ray diffraction patterns showed the amorphous character of the bromoacetylated starches.