Determine by liquid chromatography.
Solvent mixture: 35 volumes of water and 65 volumes of acetonitrile.
Test solution: Weigh and powder 20 tablets. Disperse a quantity of the powder containing 30 mg of pioglitazone in 20 ml of water, with the aid of ultrasound .Add about 150ml of solvent mixture and mix with the aid of ultrasound for 15 minutes, dilute to 250.0 ml with the solvent mixture and filter.
Reference solution: A 0.0136 per cent w/v solution of pioglitazone hydrochloride reference standard in the solvent mixture.
Chromatographic system:
- A stainless steel column 25 cm x 4.6 mm, packed with octadecylsilane bonded to porous silica (5µm),
- Mobile phase; a mixture of 35 volumes of a buffer solution prepared by dissolving 1.36 g of potassium dihydrogen orthophosphate and 1.15 g of diammonium hydrogen orthophosphate in 1000 ml of water, adding 1.0 ml of triethylamine and adjusting the pH to 5.0 with O.P.A. and 65 volumes of acetonitrile,
- Flow rate ; 1.5 ml per minute,
- Spectrophotometer set at 270 nm,
- Injection volume; 20µl.
Inject the reference solution. The test is not valid unless the tailing factor is not than 2.0 and the relative standard deviation for replicate injections is not than 2.0 per cent .
Inject the reference solution and the test solution.
Calculate the content of Pioglitazone in the tablets.
Alternative Method: By UV Spectrophotometer
Test Solution: Weigh and powder 20 tablets. Weight sample equivalent to 25mg of Pioglitazone 50ml volumetric flask add 20ml methanol into it and sonicate to dissolve the test sample. Make up to mark with 0.1 M HCl. Filter and dilute 1ml of this solution to 50ml in 0.1 M HCl.
Reference Solution: Weigh 50mg of reference standard of Pioglitazone HCl in 50ml of volumetric flask. Add 20ml methanol into it and sonicate to dissolve. Make up to mark with 0.1 M HCl. Dilute 1ml of this solution to 50ml with 0.1 M HCl.
Check Absorbance of test as well as reference standard at about 270nm in UV Spectrophotometer.
Calculate the content of Pioglitazone in the tablets.
Formula:
Area of Test STD Wt. (mg) 1 100 50 Potency
—————–X————–X———–X——————X———–X———–X Average wt.
Area of STD 100 50 Test Wt. (mg) 1 100
Acceptance criteria: 90.0%-110.0%
