Conductometric study of antidepressant drug-cationic surfactant mixed micelles in aqueous solution.
Conductivity measurements have been carried out on aqueous solutions of two antidepressant drugs (nortriptyline hydrochloride and clomipramine hydrochloride) with four cationic surfactants (monomeric: cetyltrimethylammonium bromide, tetradecylammonium bromide; dimeric: 1,5-pentanediyl-alpha-omega-bis(hexadecyldimethylammonium bromide), 1,4-butanediyl-alpha,omega-bis(hexadecyldimethylammonium bromide) as well as with sodium chloride. Counterions from NaCl adsorb to the charged headgroup of the drug molecules and reduce the repulsion, hence cmc decreases. cmc values decreased with the addition of surfactants indicating mixed micelle formation. Experimental mole fraction of surfactants in micelle (X1) and their ideal values (X1 id) also support this explanation. Interaction parameter, beta, and excess free energy of micellization are negative suggesting synergism in mixed state. Activity coefficients are less than unity which means non-ideal mixing.
Kabir-ud-Din
Department of Chemistry, Aligarh Muslim University, Aligarh 202002, India. kabir7@rediffmail.com
Al-Ahmadi
Mohammed D A
MD
Naqvi
Andleeb Z
AZ
Akram
Mohd
M
D000929:Antidepressive Agents, Tricyclic / Q000737:chemistry*; D002997:Clomipramine / Q000737:chemistry*; D004553:Electric Conductivity; D008823:Micelles; D009661:Nortriptyline / Q000737:chemistry*; D019999:Pharmaceutical Solutions; D013501:Surface-Active Agents / Q000737:chemistry*; D014867:Water
D000929:Antidepressive Agents, Tricyclic; D008823:Micelles; D019999:Pharmaceutical Solutions; D013501:Surface-Active Agents; D014867:Water; D009661:Nortriptyline; D002997:Clomipramine