PHYSICOCHEMICAL CHARACTERIZATION OF ACID MODIFIED DIOSCOREA STARCH AND ITS EVALUATION AS DIRECTLY COMPRESSIBLE EXCIPIENT IN TABLET FORMULATION

Abstract

D. abyssinica was partially hydrolyzed in 6% HCl solution at room temperature for different lengths of time, (2, 4, 8, 16, and 32 days), dried using oven- and spray- drying techniques and subsequently investigated as directly compressible excipient in paracetamol tablet formulations. Native dioscorea starch (NDS) and oven dried acid modified dioscorea starch (AMDS) exhibited poor flow characteristics, whereas spray dried AMDS was found to be free flowing powder with 21.37 ± 1.39° angle of repose and 13.24 ± 0.76 g/sec flow rate. Both swelling power and percent solubility of the starches were found to increase with increase in temperature; AMDS showed higher percent solubility of 68.53%. Lubricant sensitivity and dilution potential of spray dried NDS and spray dried AMDS were investigated by incorporating magnesium stearate and paracetamol, respectively. In tablet formulations, spray dried AMDS and Starch 1500^® tablets were produced with acceptable tablet characteristics up to 1% and 0.5% magnesium stearate concentrations, respectively. The spray dried AMDS was able to accommodate up to 40% paracetamol with acceptable criteria.  Thus, it can be concluded that AMDS can be used as an alternative directly compressible excipient in tablet formulations.

Keywords:  Dioscorea starch, acid modification, spray drying, directly compressible excipient.