| abstract |
PURPOSE:To obtain the titled injection, having a specific pH, containing an antioxidant selected from sulfites, hydrogensulfites and pyrosulfites and cysteines, useful as an antipyretic and analgesic agent, etc., and stable for a long period. CONSTITUTION:An injection which is an aqueous solution of 3-methyl-1-phenyl-2- pyrazolon-5-one, containing one or more selected from sulfites, e.g. Na2SO3, etc., hydrogensulfites and pyropsulfites as an antioxidant and cysteines, e.g. L-cysteine, etc., having a pH within the range of 2.5-6.0, particularly 3.0-4.0 thereof. The amounts of the added ingredients are preferably 0.01-5mg/ml (0.001-0.5wt./vol%) antioxidant and 0.05-5mg/ml (0.005-0.5wt./vol%) cysteines. Remarkable stabilizing effects are obtained by adding the cysteines and antioxidant in combination. |