Abstract
The commercial production of antibiotics today uses the solvent extraction method in the extraction of antibiotics. Selection of solvent in any solvent extraction process is crucial due to technical and economic reasons. Hence, in order to get better understanding for solvent selection, the solubility of selected antibiotics such as kitasamycin, penicillin G, rifampicin and teicoplanin from aqueous buffer solution was studied using various groups of organic solvents such as alcohols, aldehydes, ketones, aliphatic hydrocarbons, kerosene and paraffin. The effects of solvent polarity, pH and type of antibiotics on solubility were explored. The polarity of solvents, in general, increases with an increase in solubility parameter and dielectric constant; and with a decrease in log P. Different groups of organic solvents exhibit different solvent polarity scales. Among them, alcohols are the most favourable solvent group for the solubilisation of antibiotics, followed by aldehydes and ketones. Meanwhile from the experimental observation, it was found that antibiotic types of kitasamycin and rifampicin displayed a very high degree of solubility especially for solvent groups of alcohol, aldehyde and ketone over the pH range.
