Determination of clorazepate dipotassium via its acid induced degradation products

ABSTRACT

Two sensitive colorimetric methods are suggested for the determination of clorazepate dipotassium via its degradation products. The procedure is based on acid hydrolysis of clorazepate dipotassium yielding two degradation products namely, 2-amino, 5-chlorobenzophenone and glycine. The hydrolysis is carried out by heating clorazepate dipotassium in 6 N HCL at 100°C for 1 hr. The first procedure depend upon determination of the correspondding produced benzophenone degradation product [after extraction byorganic solvent] diazometrically by reacting quantitatively with nitrous acid forming a diazonium salt that subsequently react with a coupling agent as alpha naphthol to give a colored azodye having a maximum absorbance at 502 nm. Beer's law is obeyed over a concentration range of 10-70 mcg / ml of clorazepate dipotassium. The second procedure depend on determination of glycine [the second degradation product] left in the aqueous layer after extraction of the corresponding benzophenone by reacting with p. benzoquinone at pH5.6 where a pink colour is obtained which absorbs maximally at 490 nm. Beer's law is obeyed over a concentration range of 32-160 mcg/ml of clorazepate dipotassium. The proposed procedure is successfully applied for the determination of clorazepate dipotassium in Tranxene capsules with mean percentage recoveries of 99.93 +/- 0.195 and 100.08 +/- 0.29 via the corresponding benzophenone and glycine degradation products respectively. The validity of the method was ascertained by the standard addition technique. The suggested procedure is suitable for stability testing of clorazepate dipotassium in bulk powder and in pharmaceutical preparation