Neostigmine Tablets
Action and use
Cholinesterase inhibitor.
Definition
Neostigmine Tablets contain Neostigmine Bromide.
Content of neostigmine bromide, C12H19BrN2O2
92.5 to 107.5% of the stated amount.
Identification
Assay
Weigh and powder 20 tablets. Transfer a quantity of the powder containing 0.15 g of Neostigmine Bromide to a semi-micro ammonia-distillation apparatus, add 20 mL of a 50% w/v solution of sodium hydroxide and 0.5 mL of a 2% solution of octan-2-ol in liquid paraffin. Pass a current of steam through the mixture, collect the distillate in 50 mL of 0.01m sulfuric acid VS until the total volume is about 200 mL and titrate the excess of acid with 0.02m sodium hydroxide VS using methyl red solution as indicator. Repeat the operation without the powdered tablets. The difference between the titrations represents the amount of acid required to neutralise the dimethylamine produced. Each mL of 0.01m sulfuric acid VS is equivalent to 6.064 mg of C12H19BrN2O2.
Storage
Neostigmine Tablets should be protected from light.