RT Journal Article SR Electronic T1 Increasing Solubility of Enoxacin and Norfloxacin by Means of Salt Formation JF PDA Journal of Pharmaceutical Science and Technology JO PDA J Pharm Sci Technol FD Parenteral Drug Association (PDA) SP 70 OP 72 VO 40 IS 2 A1 Spurlock, Carola H. YR 1986 UL http://journal.pda.org/content/40/2/70.abstract AB 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 spectrophotometry. 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.