Stability of Drugs and Dosage Forms Sumie Yoshioka

92 Chapter 2 • Chemical Stability of Drug Substances
Figure 68. pH–rate profile for hydrolysis of azathioprine at 73°C. (Reproduced from Ref. 371 with permission.)
hydrolysis of benzodiazepines such as flutazolam and haloxazolam also exhibits complicated
pH–rate profiles owing to ionization accompanied by ring opening (Fig. 70). 94
Drug substances having three ionizable groups exhibit even more complex pH–rate
profiles. As shown in Fig. 71, hydrolysis of cefotiam exhibits a complicated pH–rate profile
Figure 69. pH–rate profile for hydrolysis of oxazolam at 37°C. (Reproduced from Ref. 93 with permission.)