Improvement of the antitumor activity of poorly soluble sapacitabine (CS-682) by using Soluplus® as a surfactant.

Sapacitabine (CS-682 or CYC682; 1-[2-C-cyano-2-deoxy-β-D-arabino-pentfuranosyl]N4-palmitoyl cytosine), a novel antitumor 2'-deoxycytidine analogue, shows a marked reduction in the water solubility because of the fatty acid side chain on the N4 group of the cytosine moiety. Poor water solubility is one of the important reasons why sapacitabine does not exert maximum antitumor activity. Therefore, we attempted to improve the water solubility of sapacitabine using a novel surfactant, Soluplus®, which consisted of a polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer.

Effect of aminoalkyl methacrylate copolymer E/HCl on in vivo absorption of poorly water-soluble drug.

This study aimed to investigate in vivo absorption of tacrolimus formulated as a solid dispersion using Eudragit E®/HCl (E-SD). E-SD is an aminoalkyl methacrylate copolymer that can be dissolved under neutral pH conditions. E-SD was used alone as a solid dispersion carrier and/or was mixed with tacrolimus primarily dispersed with hydroxypropylmethylcellulose (HPMC).

Aminoalkyl methacrylate copolymers for improving the solubility of tacrolimus. I: Evaluation of solid dispersion formulations.

The aim of this study was to investigate the effect of Eudragit E/HCl (E-SD) on the reprecipitation of a poorly water-soluble drug, tacrolimus. To evaluate the inhibition of reprecipitation of E-SD, reprecipitation studies on tacrolimus were conducted using a dissolution test method. Solubility of tacrolimus was measured at regular intervals in a dissolution media, in which tacrolimus was dissolved in ethanol, and the test media contained additives for inhibiting precipitation.