Original Articles: 2012 Vol: 4 Issue: 3
Extraction of sennosides from solutions by chitosan and utilization of the extract for oral dosage form
The extraction of sennoside (Sen) from a crude solution containing powdered senna leaf (SFP) by adsorption to chitosan (CS) was investigated. And the release profiles of Sen from the extract (CS-SFP) and from alginate-calcium gel beads (Alg-Ca) incorporating CS-SFP were examined. Sen adsorbed to CS was released into solution by electrostatic interactions. Negligible amounts of Sen were released into deionized water or ethanol, but significant amounts were released into physiological saline or phosphate buffer. Two species of Sen, SenA and SenB, were released from CS-SFP, and the amount released increased proportional to the amount of SFP used to prepare the CS-SFP. In dissolution tests, Alg-Ca incorporating Sen-SFP swelled without disintegrating, and SenA and SenB were simultaneously released from the Alg-Ca. And about 80% of the SenA contained in the Alg-Ca was released after 120 min. These results suggest that when CS-SFP is administered orally, Sen may be released immediately from the complex and if necessary, the release rate could be controlled by incorporating Sen into Alg-Ca and by modifying the gel matrix.