Abstract
In this study, the solubilizing effect of 4-sulphonic calix[ n]arenes on the poorly water soluble drug nifedipine was investigated. 4-Sulphonic calix[ n]arenes are water-soluble phenolic cyclooligomers that form complexes with neutral molecules such as nifedipine. Solubility experiments were performed at 30 °C using the Higuchi rotating bottle method. The amount of nifedipine in solution was determined by HPLC. The results showed that the size of the 4-sulphonic calix[ n]arenes, the pH of solubility medium, and the concentration of the calix[ n]arenes all significantly changed the solubility of nifedipine. 4-Sulphonic calix[8]arene improved the solubility of nifedipine the most, about 3 times the control at 0.008 M and pH 5, followed by 4-sulphonic calix[4]arene, about 1.5 times the control at 0.008 M and pH 5, while in the presence of 4-sulphonic calix[6]arene, the solubility of nifedipine was decreased. The possible mechanisms involving in the complexation between 4-sulphonic calix[4]arenes, 4-sulphonic calix[8]arene and nifedipine may be a combination of hydrogen bonding, hydrophobic bonding, and possibly electron donor–acceptor interactions. However, the degree to which these forces promote the formation of nifedipine:4-sulphonic calix[ n]arene complexes with increased solubility was limited by conformational changes in the 4-sulphonic calix[ n]arene molecules.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: European Journal of Pharmaceutics and Biopharmaceutics
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
