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Tuning of the Cloud Point of Promethazine Hydrochloride with Surfactants and Polymers
Author(s) -
Sayem Alam Md.,
Naqvi Andleeb Z.
Publication year - 2007
Publication title -
journal of surfactants and detergents
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.349
H-Index - 48
eISSN - 1558-9293
pISSN - 1097-3958
DOI - 10.1007/s11743-006-1008-0
Subject(s) - chemistry , cloud point , cationic polymerization , pulmonary surfactant , phenothiazine , micelle , polymer , promethazine , ionic bonding , chemical engineering , polymer chemistry , organic chemistry , aqueous solution , ion , medicine , engineering , pharmacology , biochemistry , anesthesia
The effect of additives (surfactants and polymers) and pH on the clouding behavior of promethazine hydrochloride (PMT, a phenothiazine drug) was investigated. Cloud point (CP) decreases with increase in pH due to deprotonation of drug molecules. The same trend occurs in the presence of surfactants. However, at constant pH, and depending on their structure and nature, these additives behave differently. Anionic surfactants show peaked behavior, whereas cationic (conventional as well as geminis) and non‐ionic surfactants increase the CP, although the mechanisms differ. Cationic surfactants hinder drug association (due to interaggregate repulsion) resulting in an increase in CP, while non‐ionic surfactants form mixed micelles with the drug, increasing micelle hydration and CP. Polymers can cause both a decrease as well as an increase in CP, depending on their molecular weight. A large CP increase (with the increase in surfactant concentration) for gemini surfactants suggests they are excellent candidates for drug delivery.