Chronopotentiometry and coulometric titration of n-substituted phenothiazines

Bioelectrochemistry: An Examination of Some Examples

“…For example, electrochemistry has been used to monitor the stability of ascorbic acid, 45 vitamin A, 46 L-dopa, 47 diazepoxide tranquilizers, 48 andphenothiazine major tranquilizers. 49 An interesting example of the importance of redox chemistry to drug activity is provided by the large amount of work on the neurotoxic compound, 6-hydroxydopamine (Structure 15). Because of its structural similarity to the adrenergic neurotransmitters, it is absorbed and concentrated in adrenergic nerve cells.…”

“…Correlations between electrochemical oxidation and metabolic degradation of drugs are quite clear in many cases, and the electrochemical evidence is useful in predicting metabolic routes. For example, electrochemical oxidation of the major tranquilizer chlorpromazine leads to the sulfoxide, 49 a major metabolic product. Furthermore, the electrochemical oxidation proceeds through a cation radical intermediate which is too short-lived to be observed metabolically, but is the initial product of all proposed chlorpromazine degradation schemes.…”

Thin-layer differential pulse voltammetric determination of chlorpromazine in biological fluids

“…The second step involves oxidation of CPZ** to pro duce the sulfoxide. Patriarche and coworkers used chronopotentiometry to measure the Ej/4 for chlorpromazine oxidation [17,18]. They also developed a method for the coulometric titration of chlorpromazine with electro generated cerium(I V) in which they were able to détermine 0.25-20 mg of chlorpromazine.…”

Oxidative Reactions of Hydroxylated Chlorpromazine Metabolites

“…The product is voltammetrically and spectroscopically indistinguishable from oxidized I1 quinone (VI). An intermediate is observed during oxidation, which is not present after four electrons have been passed, and which has a voltammogram consistent with Structure V. The electrolysis of I occurs in two distinct phases: a rapid, initial oxidation corresponding to the consumption of I to form V and VI and a slower phase corre- Although several reports have been published on the electrochemical oxidation of chlorpromazine in acidic media (17)(18)(19), the author is unaware of any studies near physiological pH. Figure 4 indicates that the product of the oxidation rapidly degrades to an electroinactive product, probably the sulfoxide.…”