Increasing solubility of enoxacin and norfloxacin by means of salt formation
Spurlock, C.H.
Journal of Parenteral Science and Technology a Publication of the Parenteral Drug Association 40(2): 70-72
1986
ISSN/ISBN: 0279-7976 PMID: 3459849 Document Number: 271147
A simple method for determining the comparative solubilities of various salt forms of insoluble or slightly soluble drugs is described. FDA-accepted acids, bases, and amino acids are suspended in water with equimolar amounts of a compound having an acidic or basic function. After sonication and filtration, the supernatant is assayed for active drug concentration by ultraviolet spectrophometometry. The method is applied to two slightly soluble antiinfective drugs, enoxacin and norfloxacin, increasing their solubility from less than 0.1 mg/ml to greater than 200 mg/ml in pH 7.4 phosphate buffer.