- British Pharmacopoeia Volume III
- Formulated Preparations: Specific Monographs
Paracetamol Capsules |
Analgesic; antipyretic.
Paracetamol Capsules contain Paracetamol.
The capsules comply with the requirements stated under Capsules and with the following requirements.
95.0 to 105.0% of the stated amount.
Shake a quantity of the contents of the capsules containing 0.5 g of Paracetamol with 20 mL of acetone, filter, evaporate the filtrate and dry at 105°.The infrared absorption spectrum of the dried residue, Appendix II A, is concordant with the reference spectrum of paracetamol (RS 258).
Comply with the requirements for Monographs of the British Pharmacopoeia in the dissolution test for tablets and capsules, Appendix XII B1.
(a) Use Apparatus 2, rotating the paddle at 50 revolutions per minute.
(b) Use 900 mL of phosphate buffer pH 5.8, at a temperature of 37°, as the medium.
After 45 minutes withdraw a 20 mL sample of the medium and measure the absorbance of the filtered sample, diluted with 0.1M sodium hydroxide to give a solution expected to contain about 0.00075% w/v of Paracetamol at the maximum at 257 nm, Appendix II B, using 0.1M sodium hydroxide in the reference cell.
Calculate the total content of paracetamol, C8H9NO2, in the medium taking 715 as the value of A(1%, 1 cm) at the maximum at 257 nm.
Carry out the method for liquid chromatography, Appendix III D. Prepare the solutions immediately before use and protect from light.
(1) Disperse a quantity of the contents of the capsules containing 0.2 g of Paracetamol in 8 mL of the mobile phase with the aid of ultrasound, add sufficient mobile phase to produce 10 mL, mix well and filter.
(2) Dilute 1 volume of solution (1) to 20 volumes with the mobile phase and dilute 1 volume of the resulting solution to 20 volumes with the mobile phase.
(3) 0.002% w/v each of 4-aminophenol and paracetamol BPCRS in the mobile phase.
(4) Dilute a 0.02% w/v solution of 4′-chloroacetanilide in methanol with the mobile phase to produce a solution containing 0.00002% w/v of 4′-chloroacetanilide.
(a) Use a stainless steel column (25 cm × 4.6 mm) packed with octylsilyl silica gel for chromatography (5 µm) (Zorbax Rx C8 is suitable).
(b) Use isocratic elution and the mobile phase described below.
(c) Use a flow rate of 1.5 mL per minute.
(d) Use a column temperature of 35°.
(e) Use a detection wavelength of 245 nm.
(f) Inject 20 µL of each solution.
(g) Allow the chromatography to proceed for 12 times the retention time of the principal peak.
250 volumes of methanol containing 1.15 g of a 40% w/v solution of tetrabutylammonium hydroxide, 375 volumes of 0.05m disodium hydrogen orthophosphate and 375 volumes of 0.05m sodium dihydrogen orthophosphate.
The test is not valid unless, in the chromatogram obtained with solution (3), the resolution factor between the two principal peaks is at least 4.0.
In the chromatogram obtained with solution (1):
the area of any peak corresponding to 4-aminophenol is not greater than the area of the corresponding peak in the chromatogram obtained with solution (3) (0.1%);
the area of any peak corresponding to 4′-chloroacetanilide is not greater than the area of the principal peak in the chromatogram obtained with solution (4) (10 ppm);
the area of any other secondary peak is not greater than the area of the principal peak in the chromatogram obtained with solution (2) (0.25%).
Weigh the contents of 20 capsules. Carry out the method for liquid chromatography, Appendix III D. Prepare the solutions immediately before use and protect from light.
(1) Disperse a quantity of the contents of the capsules containing 0.5 g of Paracetamol in 80 mL of the mobile phase with the aid of ultrasound, add sufficient mobile phase to produce 100 mL, mix well, filter and dilute 1 volume of the resulting solution to 100 volumes with the mobile phase.
(2) 0.005% w/v of paracetamol BPCRS in the mobile phase.
(3) 0.002% w/v each of 4-aminophenol and paracetamol BPCRS in the mobile phase.
(a) Use a stainless steel column (25 cm × 4.6 mm) packed with octylsilyl silica gel for chromatography (5 µm) (Zorbax Rx C8 is suitable).
(b) Use isocratic elution and the mobile phase described below.
(c) Use a flow rate of 1.5 mL per minute.
(d) Use a column temperature of 35°.
(e) Use a detection wavelength of 245 nm.
(f) Inject 20 µL of each solution.
250 volumes of methanol containing 1.15 g of a 40% w/v solution of tetrabutylammonium hydroxide, 375 volumes of 0.05m disodium hydrogen orthophosphate and 375 volumes of 0.05m sodium dihydrogen orthophosphate.
The test is not valid unless in the chromatogram obtained with solution (3), the resolution factor between the two principal peaks is at least 4.0.
Calculate the content of C8H9NO2 in the capsules, using the declared content of C8H9NO2 in paracetamol BPCRS.
Paracetamol Capsules should be protected from light.