Determined by liquid chromatography.
Reference solution: A 0.005 per cent w/v solution of Piroxicam reference standard in 0.1 M methanolic HCl.
Test solution: Weigh and powder 20 tablets. Dissolve a quantity of powder containing about 50mg of Piroxicam in 100ml of 0.1M methanolic HCl. Further dilute 1.0ml of this solution to 100ml with same solvent.
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 45 volumes of methanol and 55 volumes of a buffer solution prepared by diluting a mixture of 7.72gm of anhydrous citric acid in 400ml of water and 5.3gm of sodium phosphate in 100ml of water to produce 1000ml with water.
- Flow rate: 1.2ml per minute,
- Spectropohtometer set at 254nm,
- Injection volume: 20µl
Inject the reference solution. The test is not valid unless 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 Piroxicam.
Alternative method: (By UV spectrophotometer)
Reference solution:Weigh 25mg of Piroxicam 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 methanol.
Test preparation: Weigh and powder 20 tablets. Weigh sample containing 25mg of Piroxicam in to 100ml volumetric flask. Add 10ml of methanol to dissolve the sample. Dilute this upto the mark. Filter and dilute it further 2ml to 50ml in methanol.
Scan the solution by UV Spectrophotometer. It will give absorbance maxima at about 325nm. Note down the reading and calculate the content of Piroxicam in tablet.
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) 2 100
Acceptance criteria: 95.0%-105.0%
