Cloud point variation of amphiphilic drug promethazine hydrochloride with added surfactants

Clouding phenomenon in amphiphilic systems: A review of five decades

Phase separation in amphiphilic systems is an important phenomenon. The temperature at which an amphiphilic solution phase separates is known as Cloud Point (CP). This article reviews in detail the process of phase separation in various amphiphiles (surfactants, polymers and drugs) and effect of different classes of additives on the CP of these amphiphilic systems. Ions affect the CP of drugs in a different way: kosmotropes and hard bases decrease while chaotropes and soft bases increase the CP of nonionic and cationic surfactants. Anionic surfactants show CP in presence of quaternary salts only. Thus, depending upon the nature and concentration of additive, the CP of an amphiphilic system gets increased or decreased and, hence, properties of the system may be tuned as per the need and use. A system with CP at high concentration can be made to phase separate at lower concentration by simply introducing an appropriate additive in it. This makes the system cost effective. On the other hand, if not required, a low CP can be enhanced with the help of another type of a suitable additive.

Clouding behavior of antidepressant drug–additive system in ethylene glycol/glycerol–water mixed media and their thermodynamic parameters at cloud point

The influence of ethylene glycol (EG)/glycerol(GL)–water mixed media on clouding action of an amphiphilic drug, amitriptyline hydrochloride was studied in presence and absence of inorganic salts in selected compositions of EG–WR and GL–WR mixed media.

Interactions of phenothiazine drugs with surfactants: a detailed physicochemical overview

Phenothiazine drugs have been the subject of great interest due to their interesting aggregation properties and ability to interact with surfactants, model lipid bilayers, and biomembranes. Since these drugs show enormous pharmacological actions and deposits on the biomembranes, their pharmacological activities seem to be related to the drug-membrane interactions or to the absorbability on the membrane. Further, the mechanisms for the various biological activities of phenothiazines can be explained by exploring these drug-membrane interactions. Keeping these points in view, many researchers have investigated the interactions of these drugs with surfactants. This review describes the physicochemical aspects of the interactions between phenothiazine drugs and surfactants which have been discussed under three sections: (i) micellar and interfacial studies, (ii) spectroscopic studies, (iii) phase separation studies (CP) and (iv) miscellaneous.