Uptake of Phenothiazine Tranquilizers by Lauromacrogol Micelles in Acidic Solution

• Published in: Chemical & pharmaceutical bulletin Vol. 32; no. 8; pp. 3299 - 3304
• Main Authors: TOMIDA, HISAO, KIRYU, SETSUO, YOTSUYANAGI, TOSHIHISA, IKEDA, KEN
• Format: Journal Article
• Language: English
• Published: Tokyo The Pharmaceutical Society of Japan 01.01.1984; Maruzen
• Subjects: Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Micelles. Thin films; mixed micelle; Structure effect; Non ionic surfactant; Micelle; Partition coefficient; Phenothiazine derivatives; Solubilization; Ethylene oxide polymer; Tranquillizer; Adsorption; Numerical data; Medium effect; Ionic strength; PH; Organic compounds
• ISSN: 0009-2363; 1347-5223
• DOI: 10.1248/cpb.32.3299

The uptake of the phenothiazine tranquilizers by lauromacrogol (PLE) micelles was studied in relation to ionic strength, pH and the chemical structure of the phenothiazines. The phenothiazine uptake could be described by a Langmuir type equation. The number of mol of chlorpromazine bound per mol of PLE at saturation, n, increased with increasing ionic strength, but the binding constant, K, changed in the opposite manner. The combined binding constant, nK, showed an almost constant value in the range of ionic strength up to 0.14 and then increased. There was no pH-dependency of the micellar uptake (pH 3.0-6.0) at constant ionic strength (μ=0.14), indicating that only the cationic form of the phenothiazine was involved in the interaction. The value of nK was fairly well correlated with the critical micelle concentration of the phenothiazines. The results obtained suggest that the phenothiazine cations were oriented in PLE micelles so as to form mixed micelles.