Mixed micelles of amphiphilic drug promethazine hydrochloride and surfactants (conventional and gemini) at 293.15 K to 308.15 K: Composition, interaction and stability of the aggregates

Micellization of an amphiphilic phenothiazine drug promethazine hydrochloride (PMT) in presence of conventional (CTAB and TTAB) as well as gemini (16-s-16 and 14-s-14, s = 4–6) cationic surfactants has been studied conductometrically at different temperatures. Critical micelle concentration values (cmc and cmcid) indicate mixed micelle formation among the two components. Micellar mole fractions of surfactants (X1, X1M and X1id) show greater contribution of surfactants. Interaction parameter, β, suggests attractive interactions in the mixed systems. The thermodynamic parameters suggest dehydration of hydrophobic part of the drug at higher temperatures.

Graphical abstractEffect of temperature on the critical micelle concentration (cmc) of pure drug (PMT) and surfactants (conventional and gemini).Figure optionsDownload full-size imageDownload high-quality image (65 K)Download as PowerPoint slideResearch highlights► Surfactants are generally used as drug carriers in pharmaceuticals. ► Presence of surfactants may alter the micellization tendency of a drug which may affect the activity of the drug. ► Therefore, it is important to have knowledge of the effect of surfactants on micelle formation of drugs and the related energetics. ► Keeping this in mind, effect of cationic surfactants on the micellization of promethazine hydrochloride is seen.