Determined by liquid chromatography.
Reference solution: Weigh 25mg of olanzapine reference standard in 50ml volumetric flask. Add 10ml of mobile phase to dissolve the standard. Dilute upto the mark with mobile phase. Dilute 5ml of this solution to 50ml in mobile phase. Filter the solution and inject.
Test preparation: Weigh and powder 20 tablets. Weigh sample containing 5mg of olanzapine in to 100ml volumetric flask. Add 10ml of mobile phase to dissolve the sample. Dilute this upto the mark. Filter and inject the sample.
Chromatography System:
- A stainless steel column 25cm X4.6mm, packed with octadecylsilane bonded to porous silica (5µm)
- Mobile Phase: A mixture of 70 volumes of buffer solution prepared by dissolving 3gm of ammonium dihydrogen orthophosphate in 900ml water, add 2ml of triethylamine and dilute to 1000ml with water. Adjust the pH to 2.5 with orthophosphoric acid and 30 volumes of methanol
- Flow rate: 1ml per minute,
- Spectropohtometer set at 260nm,
- Injection volume: 10µl
Inject the reference solution. The test is not valid unless the tailing factor is not more than 2.0, the column efficiency is not less than 2500 theoratical plates. The relative standard deviation for replicate injections is not more than 2 per cent.
Inject the reference solution and the test solution.
Calculate the content of Olanzapine.
Formula:
Area of Test STD Wt.(mg) 5 100 Potency
—————–X————–X———X—————–X————–X Average weight
Area of STD 50 50 Test Wt.(mg) 100
Alternative method: (By UV spectrophotometer)
Reference solution:Weigh 25mg of olanzapine reference standard in 50ml volumetric flask. Add 10ml of methanol and dissolve the standard. Dilute upto the mark with methanol. Dilute 1ml of this solution to 50ml in 0.1M HCl.
Test preparation: Weigh and powder 20 tablets. Weigh sample containing 10mg of olanzapine in to 100ml volumetric flask. Add 10ml of methanol to dissolve the sample. Dilute this upto the mark. Filter and dilute it further 5ml to 50ml in 0.1M HCl.
Scan the solution by UV Spectrophotometer. It will give absorbance maxima at about 260nm. Note down the reading and calculate the content of olanzapine in tablet.
Formula:
Acceptance criteria: 90.0%-110.0%
Formula:
Area of Test STD Wt.(mg) 1 100 50 Potency
—————–X————–X———X—————–X——–X———–X Average weight
Area of STD 50 50 Test Wt.(mg) 5 100
Acceptance criteria: 90.0%-110.0%
