An approach on pregelatinized cassava starch phosphate esters as hydrophilic polymer excipient for controlled release table

This study describes a new approach on pregelatinized cassava starch phosphate as hydrophilic polymer excipient for controlled released tablet. There are two classes of starch phosphate esters, substituted starch phosphate esters dan cross linked starch esters. First, pregelatinized cassava starch was phosphorylated by adding phosphorous oxychloride (POCI₃) for making cross-linked reaction (CPCS). Secondly, pregelatinized cassava starch was phosphorylated by adding sodium monohydrogen phosphate (Na₂,HPO₄) for making substituted reaction (PCSN). Both pregelatinized starch phosphates subsequently were used as hydrophilic polymer matrix tablet controlled release with various concentrations. The tablets were prepared separately by directing compression process and theophyline was used as a model of the active ingredient. The USP Basket was selected to perform the dissolution test of the tablets, which carried out separately in 0.1 N HCI (pH 1.8) and in phosphate buffer of pH 7.2 both for 3 h. The result of these studies indicated that CPCS and PCSN were suitable material for the matrix tablet controlled release at 30-50% w/w concentration of theophylline. The release profiles all of the drugs were follow zero-order kinetics. The highest polymeric concentration of CPCS (50% w/w) indicated the slowest rate of drug release. The drug release from all tablets may be controlled by combination of diffusion and erosion delivery system. The pregelatinized cassava starch phosphate CPCS was more reasonable than PCSN for controlled release tablet dosages form as hydrophilic polymer excipient.