Bupivacaine Hydrochloride Injection is a sterile solution of Bupivacame Hydrcchlonde in Water for Injection. Usual strengths: The equivalent of 25, 50 and 75 mg of anhydrous bupivacame hydrcchlonde in 10 ml. Storage: Store in single dose or multiple dose containers, preferably of Type 1 glass. Labelling: The label states the strength in terms of the equivalent amount of anhydrous bupivacaine hydrcchloride in a suitable dose-volume. STANDARDS Bupivacaine Hydrcchlonride Injection contains not less than 92.5 per cent and not more than 107.5 per cent of the stated amount of anhydrous bupivacaine hydrochloride. C18H28N2O,HCI. Identification: A: To a volume equivalent to 25 mg of anhydrous bupivacaine hydrochloride add 2 ml of strong ammonia solution, shake and filter. Wash the precipitate with water and dry at 60° at a pressure of 2 kPa for 16 hours. The infra-red absorption spectrum of the dried residue. Appendix 5.4, is concordant with the reference spectrum of bupivacaine. B: Dilute a suitable volume with 0.1M hydrochloric acid to produce a solution containing the equivalent of 0.05% w/v of anhydrous bupivacame hydrcchlonde. The light absorption in the range 230 to 360 nm exhibits two maxima at about 263 rim and 271 run; absorbance at about 263 nm, about 0.70 and at about 271 nm, about 0. 57, Appendix 5.5 C: To a volume equivalent to 50 mg of anhydrous bupivacaine hydrochloride add 15 ml of picric acid solution: the precipitate, after rapid washing with a small quantity of water followed by successive quantities, each of 2 ml, of methanol and ether melts at about 194°. Appendix 8.8. D: To a volume equivalent to 50 mg of anhydrous bupivacaine hydrcchlonde add 2 ml of a 10% w/v solution of disodium hydrogen phosphate and sufficient iodine solution to produce a distinct brown colour. Remove the excess iodine by adding 0.1M sodium thiosulphate; no pink colour is produced. pH: Between 4.0 and 6.5, Appendix 8.11. 2,6-Dimethylaniline: To a volume equivalent to 25 mg of anhydrous bupivacaine hydrochloride add water, if necessary, to produce 10 ml and sufficient 2M sodium hydroxide to make the solution just alkaline. Extract with three quantities, each of 5 ml, of chloroform. Dry the combined extracts over anhydrous sodium sulphate, filter, wash the filter with 5 ml of chloroform and evaporate the filtrate to dryness using a rotary evaporator. Dissolve the residue in 2 ml of methanol. Complete the test described under Bupivacaine Hydrcchlonde beginning at the words "add 1 ml of a freshly prepared 1 % w/v solution of 4dimethylammobenzaldehyde... ". Any yellow colour produced is not more intense than that obtained with a solution prepared at the same time and in the same manner using 10 ml of a solution in water containing 1 ug of 2,6-dimethylaniline in place of the injection being examined. Related substances: Carry out the method for thin-layer chromatography. Appendix 4.6, using silica gel G as the coating substance and a mixture of 100 volumes of methanol and 0.1 volume of strong amimionia solution as the mobile phase. Apply separately to the plate 10 g1 of each of the following solutions. For solution (1) evaporate almost to dryness a volume equivalent to 0.1 g of anhydrous bupivacaine hydrochloride using a rotary evaporator, add. sufficient methanol to the residue to produce 2 ml. mix well. centrifuge and use the supernatant.