Measurement and Correlation of the Solubility for Camptothecine in Different Organic Solvents

Dissolution thermodynamics of camptothecine in chloroform, methanol, ethanol, and {chloroform + (methanol or ethanol)} mixed organic solvents were studied and correlated. The solubility of camptothecine in the above solvents was measured over the temperature range of 275.76-328.42 K at around 3 K intervals at atmospheric pressure. Experimental results showed that the solubility of camptothecine in the mixtures solvents increased with the increasing temperature. The mole fraction solubility of camptothecine reached a maximum at the mole fraction of chloroform 0.8016 in chloroform + methanol mixed solvent and 0.8031 in chloroform + ethanol mixed solvent. The experimental solubility data were well-correlated by using the modified Apelblat equation, the lambda h equation, and the ideal equation, respectively. The lambda h equation was proved to be the best-fit model for correlating the solubility of camptothecine from the analysis of the Akaike's Information Criterion (AIC).