INTERACTION OF TEMAZEPAM WITH CERTAIN MACROMOLECULES: V- THERMODYNAMICS OF TEMAZEPAM SOLUBILIZATION

Mulley, B. A.; Aboutaleb, A. E.; Abdel Rahman, Aly A.; Ahmed, S. M.

doi:10.21608/bfsa.1988.73269

INTERACTION OF TEMAZEPAM WITH CERTAIN MACROMOLECULES: V- THERMODYNAMICS OF TEMAZEPAM SOLUBILIZATION

Document Type : Original Article

Authors

¹ School of Pharmacy, Bradford University, England

² Department of Industrial Pharmacy, Faculty of Pharmacy, Assiut University, Assiut, Egypt

10.21608/bfsa.1988.73269

Abstract

Temazepam was solubilized by series of non-ionic surfactant solutions including polysorbates, Eumulgins, Brjs, Myrjs and cetomacrogol as well as ionic ones including sodium lauryl sulphate and cetrimide at different temperatures. Among the non-ionic surfactant solutions investigated, polysorbate 80 was found to be the most efficient solubilizer at different temperatures investigated, while Myrj 59 was the least. For the ionic ones, sodium lauryl sulphate proved to be more efficient than cetrimide.
Thermodynamic parameters for the solubilization of temazepam in polysorbates and Eumulgins were calculated in order to investigate the thermal process of micellar solubilization. These parameters include the heat of solution, DH, the free energy change for the transfer of temazepam from aqueous phase to micellar phase. DG and the entropy of solubilization, DS.
For all systems DG was a negative value indicating spontaneous solubilization. The positive values of entropy, DS, suggest a decrease in the degree of ordering when temazepam dissolved in the micellar phase. This positive values of entropy also implies that temazepam molecules into micelle interior.