Dispersible Paracetamol Tablets

General Notices

Action and use

Analgesic; antipyretic.

Definition

Dispersible Paracetamol Tablets contain Paracetamol in a suitable dispersible basis.

The tablets comply with the requirements stated under Tablets and with the following requirements.

Content of paracetamol, C₈H₉NO₂

95.0 to 105.0% of the stated amount.

Identification

A. Disperse in water to form a uniform suspension.

B. The light absorption, Appendix II B, in the range 230 to 350 nm of the final solution obtained in the Assay exhibits a maximum only at 257 nm.

C. 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 toluene, 25 volumes of acetone and 65 volumes of chloroform as the mobile phase but allowing the solvent front to ascend 14 cm above the line of application. Apply separately to the plate 40 µL of each of solutions (1), (2) and (3). Pour the mobile phase into the unlined tank, immediately place the prepared plate in the tank and close the tank. For solution (1) add 50 mL of ethanol (96%) to a quantity of the powdered tablets containing 0.10 g of Paracetamol, shake for 10 minutes, add sufficient ethanol (96%) to produce 100 mL and filter. Solution (2) contains 0.10% w/v of paracetamol BPCRS in ethanol (96%). For solution (3) dissolve 0.25 g of 4′-chloroacetanilide and 0.10 g of paracetamol in sufficient ethanol (96%) to produce 100 mL. After removal of the plate, dry it in a current of warm air and examine under ultraviolet light (254 nm). The principal spot in the chromatogram obtained with solution (1) corresponds to that in the chromatogram obtained with solution (2).The test is not valid unless the chromatogram obtained with solution (3) shows two clearly separated principal spots, the spot corresponding to 4′-chloroacetanilide having the higher Rf value.

Tests

Disintegration

Comply with the requirements for Dispersible Tablets.

Related substances

Carry out the method for liquid chromatography, Appendix III D, using the following solutions. Prepare the solutions immediately before use and protect from light. For solution (1) disperse a quantity of powdered tablets containing to 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. For solution (2) dilute 1 volume of solution (1) to 20 volumes with mobile phase and dilute 1 volume of this solution to 20 volumes with mobile phase. Solution (3) contains 0.002% w/v each of 4-aminophenol and paracetamol BPCRS in the mobile phase.Solution (4) contains 0.00002% w/v of 4′-chloroacetanilide in the mobile phase.

The chromatographic procedure may be carried out using (a) a stainless steel column (25 cm × 4.6 mm) packed with octylsilyl silica gel for chromatography (5 µm) (Zorbax Rx C8 is suitable), (b) as the mobile phase with a flow rate of 1.5 mL per minute, with a temperature of 35°C, a mixture of 250 volumes of methanol containing 1.15 g of a 40% v/v solution of tetrabutylammonium hydroxide with 375 volumes of 0.05m disodium hydrogen orthophosphate and 375 volumes of 0.05m sodium dihydrogen orthophosphate and (c) a detection wavelength of 245 nm.

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.

Inject solution (1) and allow the chromatography to proceed for 12 times the retention time of the principal peak. 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 solution (3) (0.1%), the area of any peak corresponding to 4′-chloroacetanilide is not greater than the area of the principal peak in solution (4) (10 ppm) and no other impurity is greater than the area of the principal peak obtained with solution (2) (0.25%).

Assay

Weigh and powder 20 tablets. Add 50 mL of 0.1m sodium hydroxide slowly to a quantity of the powder containing 0.2 g of Paracetamol, dilute with 100 mL of water, shake for 15 minutes and add sufficient water to produce 250 mL. Mix, filter and dilute 10 mL of the filtrate to 100 mL with water. Add 10 mL of the resulting solution to 10 mL of 0.1m sodium hydroxide, dilute to 100 mL with water and measure the absorbance of the resulting solution at the maximum at 257 nm, Appendix II B. Calculate the content of C₈H₉NO₂ taking 715 as the value of A(1%, 1 cm) at the maximum at 257 nm.

Storage

Dispersible Paracetamol Tablets should be protected from light.