RT Journal Article SR Electronic T1 Optimization of Autoclave Cycles and Selection of Formulation for Parenteral Products, Part II: Effect of Counter-Ion on pH and Stability of Diatrizoic Acid at Autoclave Temperatures JF PDA Journal of Pharmaceutical Science and Technology JO PDA J Pharm Sci Technol FD Parenteral Drug Association (PDA) SP 72 OP 77 VO 38 IS 2 A1 Wang, Y. J. A1 Dahl, T. C. A1 Leesman, G. D. A1 Monkhouse, D. C. YR 1984 UL http://journal.pda.org/content/38/2/72.abstract AB Effect of counter-ions on stability of a drug substance was illustrated in this study. During autoclave sterilization of diatrizoic acid solutions, anilide hydrolysis resulted information of desacetyldiatrizoic acid, a free aromatic amine. Under the same autoclave conditions, more of desacetyldiatrizoic acid was produced in the diatrizoic acid solution neutralized with sodium hydroxide than those neutralized with either meglumine or ammonia. Stability difference in the presence of each counter-ion was attributed to varying pH’s at autoclave temperatures. By using a nonisothermal approach, the kinetic parameters were determined by a nonlinear least square program. This information can be particularly useful when autoclave sterilization cycles are to be optimized.