mesoridazine

Absorption

Well absorbed from the gastrointestinal tract.

Toxicity

Oral LD50 is 560 ± 62.5 mg/kg and 644 ± 48 mg/kg in mouse and rat, respectively. Symptoms of overdose may include emesis, muscle tremors, decreased food intake and death associated with aspiration of oral-gastric contents into the respiratory system.

Chemical properties

Pale Pink Solid

Originator

Serentil,Sandoz,US,1970

The Uses of mesoridazine

Mesoridazine is an antipsychotic.

The Uses of mesoridazine

Mesoridazine (Thioridazine EP Impurity B) is an antipsychotic.

Background

A phenothiazine antipsychotic with effects similar to chlorpromazine.

Indications

Used in the treatment of schizophrenia, organic brain disorders, alcoholism and psychoneuroses.

Definition

ChEBI: A phenothiazine substituted at position 2 (para to the S atom) by a methylsulfinyl group, and on the nitrogen by a 2-(1-methylpiperidin-2-yl)ethyl group.

Manufacturing Process

10.0 g of 3-methylmercapto phenothiazine and 17.5 cc of acetic acid anhydride are refluxed for 8 hours from an oil bath maintained at a temperature of 180°C. After concentration of the solution the residue is crystallized from ethanol. The pure 3-methylmercapto-10-acetyl phenothiazine melts at 89° to 91°C. For the purpose of oxidation 5.0 g of 3- methylmercapto-10-acetyl phenothiazine are dissolved in 50 cc of ethanol, refluxed from an oil bath maintained at 120°C and 1.6 cc of a 40% hydrogen peroxide solution are then added dropwise in the course of 30 minutes.
Heating is continued for another 5 hours and the reaction mixture is concentrated after 50 cc of water have been added. The residue is taken up in 40 cc of benzene and the benzene layer washed with 10 cc of water. After having been concentrated, the residue, crude 3-methylsulfinyl-10-acetyl phenothiazine, is dissolved in 55 cc of a 90% methanol solution for splitting off the acetyl group and, after 2.9 g of potassium carbonate have been added, it is boiled for 2 hours under reflux on an oil bath kept at a temperature of 120°C. After concentration, the residue is taken up in 50 cc of chloroform, the chloroform layer is washed with a total of 25 cc of water, dried over potassium carbonate, filtered and concentrated. After twice crystallizing the residue, each time from 50 cc of ethanol, analytically pure 3-methylsulfinyl phenothiazine (MP 193° to 195°C) is obtained.
A mixture of 10.0 g of 3-methylsulfinyl phenothiazine (MP 193° to 195°C), 6.1 g of finely powdered sodium hydroxide and 125 cc of toluene is boiled for 1 hour under reflux with a water separator on an oil bath kept at a temperature of 150°C, while the mixture is stirred. Without interrupting the boil a solution of 7.0 g of 2-(N-methyl-piperidyl-2')-1-chloroethane (BP 84°C/10 mm Hg) in 10 cc of toluene is added dropwise in the course of 1 hour, after which boiling is continued for another 3 hours. When the reaction mixture has cooled it is first washed with 25 cc of water three times and then extracted with 75 cc of a 15% aqueous tartaric acid solution. The tartaric acid extract is shaken out with 25 cc of benzene, 20 cc of concentrated caustic soda are added until the phenolphthalein reaction is alkaline, and the separated oily base is taken up in a total of 150 cc of benzene.
After having been washed with 50 cc of water the benzene layer is dried over potassium carbonate, filtered, allowed to stand over 10 g of alumina for about 1? hours for partial decolorization, filtered again and concentrated under reduced pressure. The oily base which remains as a residue is directly converted into the tartrate. A solution cooled to 0°C, of 6.50 g of the free base in 100 cc of acetic acid ethyl ester is thoroughly shaken and poured into an ice cold solution of 2.66 g of tartaric acid in 410 cc of acetic acid ethyl ester. The precipitated, analytically pure, tartrate of 3-methylsulfinyl-10-[2'-Nmethyl-piperidyl-2')-ethyl-l']-phenothiazine melts at 115° to 120°C (foam formation) and sinters above 80°C. The base is reacted with benzene sulfonic acid in a suitable solvent to give the besylate.

brand name

Serentil (Novartis).

Therapeutic Function

Tranquilizer

Pharmacokinetics

Mesoridazine, the besylate salt of a metabolite of thioridazine, is a phenothiazine tranquilizer. Pharmacological studies in laboratory animals have established that mesoridazine has a spectrum of pharmacodynamic actions typical of a major tranquilizer. In common with other tranquilizers it inhibits spontaneous motor activity in mice, prolongs thiopental and hexobarbital sleeping time in mice and produces spindles and block of arousal reaction in the EEG of rabbits. It is effective in blocking spinal reflexes in the cut and antagonizes d-amphetamine excitation and toxicity in grouped mice. It shows a moderate adrenergic blocking activity in vitro and in vivo and antagonizes 5-hydroxytryptamine in vivo. Intravenously administered, it lowers the blood pressure of anesthetized dogs. It has a weak antiacetylcholine effect in vitro.

Metabolism

Not Available