Ch

carmethizole

Scheme 68. Consecutive loss of carbamate groups in carmethizole (NSC-602668). The reactivity of one carbamate group is greater than that of the other. (Reproduced from Ref. 46 with permission.)

A good example of consecutive reactions is the degradation of carmethizole (NSC-602668), an experimental cytotoxic agent (Scheme 68).44 The hydrolysis of hydrocortisone hemisuccinate (Fig. 11)30 and alkaline epimerization followed by hydrolysis of etoposide (Fig. 12)156 157 fit this mathematical model even though their degradation pathways are more complex.

2.2.3.1.g. Pseudo-First-Order Reversible and Consecutive Reactions

When drug D is reversibly converted to P1, which is reversibly converted to P2 by apparent first-order kinetics, Equations (2.31) and (2.32) represent the rate and integrated expressions, respectively.

hydrocortisone hemisuccinate hydrocortisone hemisuccinate

Figure 11. Time course of hydrolysis of hydrocortisone hemisuccinate (pH 6.9, 70°C). (Reproduced from Ref. 30 with permission.)

Figure 11. Time course of hydrolysis of hydrocortisone hemisuccinate (pH 6.9, 70°C). (Reproduced from Ref. 30 with permission.)

Figure 12. Time courses of epimerization and hydrolysis of etoposide (pH 10, 37°C). (Reproduced from Ref. 157 with permission.)

Was this article helpful?

0 0
Drug Addiction

Drug Addiction

If you're wanting to learn about drug addiction... Then this may be the most important letter you'll ever read You Are Going To Get A In Depth Look At One Of The Most Noteworthy Guides On Drug Addiction There Is Available On The Market Today. It Doesn't Matter If You Are Just For The First Time Looking For Answers On Drug Addiction, This Guide Will Get You On The Right Track.

Get My Free Ebook


Post a comment