Determined by liquid chromatography.
Reference solution: Weigh 25mg of Clonazepam reference standard in 50ml volumetric flask. Add 10ml of mobile phase and dissolve. Sonicate the standard & shake by mechanical means for 5 min, add 40ml of mobile phase and shake. Dilute 1ml to 50ml with mobile phase. Shake and filter.
Test solution: Weigh and powder 20 tablets. Weight sample containing 1mg Clonazepam in 100ml of volumetric flask. Add 10ml of mobile phase and sonicate and makeup to the mark with mobile phase. Filter the solution and inject.
Chromatographic system:
- A stainless steel column 15cm X4.6mm, packed with octadecylsilane bonded to porous silica (5µ)
- Mobile Phase: Buffer:Acetonitrile(50:50)
Buffer: 6.8gm KH2PO4→500ml pH-3
- Flow rate: 1.0ml per minute,
- Spectrophotometer set at 254nm,
- Injection volume: 20µl
Inject reference solution. The test is not valid unless the relative standard deviation for replicate injections for each peak is not more than 2.0 percent.
Inject reference solution and the test solution.
Calculate the content of Clonazepam in tablet.
Acceptance criteria: 90.0%-110.0%
Formula:
Area of Test STD Wt.(mg) 1 100 Potency
—————–X—————–X———-X——————-X—————-X Average weight
Area of STD 100 50 Test Wt.(mg) 100
