SOLUBILIZATION AND STABILITY OF CLONAZEPAM BY DIFFERENT CLASSES OF SURFACTANTS

Simonelli, A. P.; Aboutaleb, A. E.; Abdel-Rahman, A. A.

doi:10.21608/bfsa.1984.89866

SOLUBILIZATION AND STABILITY OF CLONAZEPAM BY DIFFERENT CLASSES OF SURFACTANTS

Document Type : Original Article

Authors

¹ School of Pharmacy, University of Connecticut, STORRS, CT 06268, U.S.A.

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

10.21608/bfsa.1984.89866

Abstract

Clonazepam a 1,4-benzodiazepine derivative acting as tranquillizer and hypnotic is practically water insoluble. It was solubilized by three different classes of surfactant solutions at pH 5,6,7 and 8 and of ionic strength (U) of 0.2. Sodium dodecyl sulphate (SDS), cetyl trimethyl ammonium bromide (CTAB) and Brij 35 were chosen for this study, which was carried out at 25, 35 and 65°. Neither the presence of the surfactant solutions in the concentrations used nor the presence of the degradation product (s) of clonazepam interfer in the spectrophotometric assay of the drug. At all the temperatures, and pH values investigated it was found that SDS solutions is the most efficient solubilizers for clonazepam followed by CTAB and Brij 35 solution respectively.
Accelerated stability study of clonazepam was carried out in different concentrations of the last mentioned solutions at 65°. The half life (t½) of clonazepam was calculated in the prepared solutions and the longest t½ for clonazepam is in SDS solution of pH 6.
The distribution coefficient (k_m) of clonazepam in the studied solutions was calculated from solubility and compared with the partition coefficient obtained from stability data (P^@).