Piroxicam Capsules
Action and use
Cyclo-oxygenase inhibitor; analgesic; anti-inflammatory.
Definition
Piroxicam Capsules contain Piroxicam.
Content of piroxicam, C15H13N3O4S
95.0 to 105.0% of the stated amount.
Identification
Tests
2-Pyridylamine
Carry out the method for thin-layer chromatography, Appendix III A, using silica gel GF254 as the coating substance and a mixture of 1 volume of diethylamine and 8 volumes of dichloromethane as the mobile phase. Apply separately to the plate 20 µL of each of the following solutions. For solution (1) shake a quantity of the contents of the capsules containing 80 mg of Piroxicam with 25 mL of dichloromethane, filter, evaporate the filtrate to dryness using a rotary evaporator and dissolve the residue in 2 mL of dichloromethane. Solution (2) contains 0.010% w/v of 2-pyridylamine in dichloromethane. After removal of the plate, allow it to dry in air and examine under ultraviolet light (254 nm). Any spot corresponding to 2-pyridylamine in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2) (0.25%).
Related substances
Carry out the method for thin-layer chromatography, Appendix III A, using silica gel GF254 as the coating substance and a mixture of 10 volumes of glacial acetic acid and 90 volumes of toluene as the mobile phase. Apply separately to the plate 7.5 µL of each of the following solutions. For solution (1) shake a quantity of the contents of the capsules containing 80 mg of Piroxicam with 25 mL of dichloromethane, filter, evaporate the filtrate to dryness using a rotary evaporator and dissolve the residue in 2 mL of dichloromethane. For solution (2) dilute 1 mL of solution (1) to 20 mL with dichloromethane. Solution (3) contains 0.20% w/v of piroxicam BPCRS in dichloromethane. For solution (4) dilute 2 mL of solution (2) to 50 mL with dichloromethane. After removal of the plate, allow it to dry in air and examine under ultraviolet light (254 nm). Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (4) (0.2%). Disregard any spot remaining on the line of application.
Dissolution
Comply with the requirements for Monographs of the British Pharmacopoeia in the dissolution test for tablets and capsules, Appendix XII B1, using as the medium 900 mL of 0.1m hydrochloric acid and rotating the basket at 100 revolutions per minute. Withdraw a 10 mL sample of the medium and measure the absorbance of the filtered sample, suitably diluted if necessary, at the maximum at 242 nm, Appendix II B. Calculate the total content of piroxicam, C15H13N3O4S, in the medium taking 352 as the value of A (1%, 1 cm) at the maximum at 242 nm.
Assay
Carry out the method for liquid chromatography, Appendix III D, using the following solutions. For solution (1) add a quantity of the mixed contents of 20 capsules containing 10 mg of Piroxicam to 150 mL of 0.01m methanolic hydrochloric acid, mix with the aid of ultrasound for 30 minutes, cool and dilute to 200 mL with the same solvent, filter through glass-fibre paper (Whatman GF/C is suitable) and use the filtrate. Solution (2) contains 0.005% w/v of piroxicam BPCRS in 0.01m methanolic hydrochloric acid.
The chromatographic procedure may be carried out using (a) a stainless steel column (30 cm × 3.9 mm) packed with octadecylsilyl silica gel for chromatography (10 µm) (µBondapak C18 is suitable), (b) as the mobile phase with a flow rate of 2 mL per minute a mixture of 60 volumes of methanol and 40 volumes of a buffer solution prepared by adding a solution containing 5.35 g of disodium hydrogen orthophosphate in 100 mL of water to a solution containing 7.72 g of citric acid in 400 mL of water and diluting to 1000 mL and (c) a detection wavelength of 242 nm.
Calculate the content C15H13N3O4S using the declared content of C15H13N3O4S in piroxicam BPCRS.