SN-38-cyclodextrin complexation and its influence on the solubility, stability, and in vitro anticancer activity against ovarian cancer.
Academic Article
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
abstract
SN-38, an active metabolite of irinotecan, is up to 1,000-fold more potent than irinotecan. But the clinical use of SN-38 is limited by its extreme hydrophobicity and instability at physiological pH. To enhance solubility and stability, SN-38 was complexed with different cyclodextrins (CDs), namely, sodium sulfobutylether -cyclodextrin (SBECD), hydroxypropyl -cyclodextrin, randomly methylated -cyclodextrin, and methyl -cyclodextrin, and their influence on SN-38 solubility, stability, and in vitro cytotoxicity was studied against ovarian cancer cell lines (A2780 and 2008). Phase solubility studies were conducted to understand the pattern of SN-38 solubilization. SN-38-CD complexes were characterized by differential scanning calorimetry (DSC), X-ray powder diffraction analysis (XRPD), and Fourier transform infrared (FTIR). Stability of SN-38-SBECD complex in pH 7.4 phosphate-buffered saline was evaluated and compared against free SN-38. Phase solubility studies revealed that SN-38 solubility increased linearly as a function of CD concentration and the linearity was characteristic of an AP-type system. Aqueous solubility of SN-38 was enhanced by about 30-1,400 times by CD complexation. DSC, XRPD, and FTIR studies confirmed the formation of inclusion complexes, and stability studies revealed that cyclodextrin complexation significantly increased the hydrolytic stability of SN-38 at physiological pH 7.4. Cytotoxicity of SN-38-SBECD complex was significantly higher than SN-38 and irinotecan in both A2780 and 2008 cell lines. Results suggest that SBECD encapsulated SN-38 deep into the cavity forming stable inclusion complex and as a result increased the solubility, stability, and cytotoxicity of SN-38. It may be concluded that preparation of inclusion complexes with SBECD is a suitable approach to overcome the solubility and stability problems of SN-38 for future clinical applications.