Physicochemical and release properties of carboxymethylated starches of Dioscorea from Jharkhand

Increasing demand and considerable attention to the non-conventional sources of starches leads to explore new sources. Starches of Dioscorea (Da1 and Da2) from Jharkhand, North Eastern region of India have been studied for its physicochemical properties. An attempt has been made to study the carboxymethylated derivatives of starches from two varieties of Dioscorea of this region. Different concentration of monochloroacetate was used to study the effect of degree of substitution (DS) on the physicochemical properties of starches. A considerable effect of DS was noticed on the ash content, amylose content, water-holding capacity, swelling and solubility power of carboxymethylated derivatives. Morphological studies showed the increase in the deformation of structure of the starch granule with an increase in the degree of substitution. FTIR confirmed the carboxymethylation reaction. TGA data of carboxymethylated starches revealed the stability to the temperature. Micromeritics of starch powder and granules showed the value which makes these starches to be utilized as an excipient. With the increase in DS, the % release of drug was found to be decreased. This further makes the carboxymethyl derivatives of Dioscorea a good source to be used as an excipient for sustained release formulations.