Determine by liquid Chromatography
Test solution: Weigh and powder 20 tablets. Weigh a quantity of the powder containing 250mg of quetiapine, disperse in 100.0 ml with the mobile phase, with the aid of ultrasound and dilute to 250.0 ml with the mobile phase. Dilute 5 ml of the solution to 50 ml with the mobile phase.
Reference solution: Weigh 58 mg of quetiapine fumarate reference standard, add 30 ml of the mobile phase and dissolve with aid of ultrasound. Cool and dilute to 50.0 ml with the mobile phase. Dilute 5.0 ml of this solution to 50.0 ml with the mobile phase.
Chromatographic system:
- A stainless steel column 25 cm x 4.6mm, packed with octadecylsilane bonded to porous silica (5µ),
- Mobile phase: a mixture 40 volumes of water and 600ml of volumes of methanol. Add 0.4ml of triethylamine and adjust pH tom 6.8 with O.P.A.,
- Flow rate: 1ml per minutes,
- Spectrophotometer set at 289 nm,
- Injection volume: 20 µl.
Inject the reference solution, and the test solution. The test is not valid unless the relative standard deviation for replicate injection is not more than 2.0 per cent.
Inject the reference solution and the test solution.
Calculate the content of Quetiapine in the tablets.
Alternative Method: By UV Spectrophotometer
Test Solution: Weigh and powder 20 tablets. Weight sample equivalent to 25mg of Quetiapine 50ml volumetric flask add 20ml methanol into it and sonicate to dissolve the test sample. Make up to mark with methanol. Filter and dilute 1ml of this solution to 25ml in methanol.
Reference Solution: Weigh 25mg of reference standard of Quetiapine Fumarate in 50ml of volumetric flask. Add 20ml methanol into it and sonicate to dissolve. Make up to mark with methanol. Dilute 1ml of this solution to 25ml with methanol.
Check Absorbance of test as well as reference standard at about 293nm in UV Spectrophotometer.
Calculate the content of Quetiapine in the tablets.
Formula:
Area of Test STD Wt. (mg) 1 50 25 Potency
—————–X——————-X——X—————X——X———–X Average wt.
Area of STD 50 25 Test Wt. (mg) 1 100
Acceptance criteria: 90.0%-110.0%
