Lomustine Capsules
Action and use
Cytotoxic alkylating agent.
Definition
Lomustine Capsules contain Lomustine.
Content of lomustine, C9H16ClN3O2
90.0 to 110.0% of the stated amount.
Identification
Carry out the following procedure in subdued light. Shake a quantity of the contents of the capsules containing 0.2 g of Lomustine with 10 mL of methanol, filter and evaporate the filtrate to dryness using a rotary evaporator on a water bath maintained at not more than 60°. The residue, after drying at 60° at a pressure not exceeding 0.7 kPa for 30 minutes, complies with the following tests.
TEST
Related substances
20 volumes of glacial acetic acid and 80 volumes of toluene.
The test is not valid unless the chromatogram obtained with solution (4) shows two clearly separated principal spots.
Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2) (0.4%) and not more than one such spot is more intense than the spot in the chromatogram obtained with solution (3) (0.2%).
50 volumes of methanol and 50 volumes of water.
When the chromatograms are recorded in the prescribed conditions, the retention time of lomustine is about 25 minutes.
In the chromatogram obtained with solution (1) the sum of the areas of any secondary peaks is not greater than the area of the principal peak in the chromatogram obtained with solution (2) (2%).
Disregard any peak with an area less than 0.05 times the area of the principal peak in the chromatogram obtained with solution (2) (0.1%).
Assay
Carry out the following procedure in subdued light. Shake a quantity of the mixed contents of 20 capsules containing 40 mg of Lomustine with 70 mL of ethanol (96%) for 20 minutes, dilute to 100 mL with the same solvent and filter. Dilute 5 mL of the filtrate to 100 mL with ethanol (96%) and measure the absorbance of the resulting solution at the maximum at 230 nm, Appendix II B. Calculate the content of C9H16ClN3O2 taking 260 as the value of A(1%, 1 cm) at the maximum at 230 nm.