Sirimarn Palawooth. Dissolution improvement of artemisinin using chitosan as a solubilizer . Master's Degree(Pharmaceutics). Mahidol University. : Mahidol University, 2553-04-27.
Dissolution improvement of artemisinin using chitosan as a solubilizer
Abstract:
Artemisinin is a potent antimalarial drug, which is very slightly soluble in water
and has a dissolution problem. The objective of this study was to improve the
solubility of artemisinin. Various sources of chitosan i.e., water soluble chitosan, crab
shells and squid pens were investigated as possible solubilizers for artemisinin.
Various concentrations (0.05, 0.10, 0.15, 0.20, 0.25, 0.50 and 1.0%w/v) were tested on
the three chitosan sources. It was revealed that at 1%w/v of squid pens chitosan, the
solubility of artemisinin was twice as high as in the water solution. Crab shells gave a
low level of solubility. Squid pens chitosan contains impurities which were
neutralized by Simulated Gastric Fluid. This product is called “Squid Pens
Lyophilized Chitosan”. The study demonstrated that the presence of 3%w/v squid
pens lyophilized chitosan improves the solubility of artemisinin effectively. An in
vitro experiment was conducted in which chitosan was demonstrated to enhance the
dissolution rate of artemisinin. It can hence be anticipated that gastrointestinal
absorption of artemisinin would also be augmented. This was only partly tested on
rats so a definite evaluation of experimental results cannot be drawn. The
incompleteness of the study was probably caused by the instability of artemisinin and
the insufficient amount of plasma sample used. With respect to the results of intestinal
absorption in the rats model, it cannot be concluded that the presence of chitosan
affected absorption characteristics of artemisinin although it was demonstrated that
chitosan could considerably enhance solubility and rate of dissolution of artemisinin,
but this needs confirmation. Further investigations should be performed as the
formulation of squid pens lyophilized-artemisinin inclusion in this study resulted in
bulking powder. Appropriate pharmaceutical technology should be applied to
improve dosage form characteristics.