Stability-indicating method for the determination of clorazepate dipotassium-II. Via N-desmethyldiazepam and determination of its degradation products.
A spectrophotometric method for the determination of the intact clorazepate dipotassium in the presence of its degradation products is developed. It depends upon preliminary hydrolysis of clorazepate dipotassium-thus liberating its equivalent of N-desmethyldiazepam which is extracted, with benzene-methylene chloride (9:1). The extract is evaporated, the residue dissolved in methanol and its absorbance measured at about 315 nm. The procedure determines 0.4-1.6 mg of clorazepate dipotassium with an accuracy of 100.2+/-0.7%. The procedure is applied successfully for the determination of clorazepate dipotassium in bulk powder and in capsules; retaining its accuracy in the presence of up to 80% degradation. Determination of the different degradation products is also possible. Thus, N-desmethyl diazepam is determined after preliminary extraction with benzene-methylene chloride mixture, followed by TLC separation, 2-amino-5-chlorobenzophenone by directly applying the first derivative spectrophotometric technique, and glycine in the aqueous layer determined colorimetrically with ninhydrin reagent in the presence of pyridine.
El-Bardicy
M G
MG
Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
Bebawy
L I
LI
Amer
M M
MM