Tetracaine hydrochloride is available as a preservative-free solution in a concentration of 10 mg/mL (1%) in 2-mL ampules and vials.3737; 3738 Each mL also contains sodium chloride 7.5 mg and hydrochloric acid and/or sodium hydroxide to adjust pH in water for injection.3737; 3738
Pontocaine brand of tetracaine hydrochloride 10 mg/mL also contains acetone sodium bisulfite.4
Tetracaine hydrochloride hyperbaric solutions are available in concentrations of 0.2 and 0.3% in dextrose 6%.4
pH
Tetracaine hydrochloride injection has a pH ranging from 3.2 to 6.0.3737; 3738
Osmolality
Tetracaine hydrochloride 10-mg/mL injection is isotonic.3737; 3738
Trade Name(s)
Pontocaine Hydrochloride
Tetracaine hydrochloride injection is used for prolonged spinal anesthesia.3737; 3738 The injection is isobaric having a specific gravity of 1.0060 to 1.0074 at 25°C, which is very similar to spinal fluid.3737; 3738 A hyperbaric solution of tetracaine hydrochloride may be prepared by diluting the 10-mg/mL injection in dextrose 10%.3737; 3738
Tetracaine hydrochloride powder for injection dissolved in spinal fluid is slightly hyperbaric. A hypobaric solution with a specific gravity of 1.000 at 25°C may be prepared by dissolving the tetracaine hydrochloride powder in sterile water for injection at a concentration of 0.1%. A hyperbaric solution of tetracaine hydrochloride may be prepared by dissolving the powder in dextrose 10% to yield a 10-mg/mL solution. The resulting solution is further diluted with an equal volume of cerebrospinal fluid to yield 5 mg/mL of tetracaine hydrochloride and dextrose.4
Tetracaine hydrochloride injection in intact vials or ampuls should be stored under refrigeration and protected from light.3737; 3738 The injection should not be used if crystals, cloudiness, or discoloration is present.3737; 3738
Tetracaine hydrochloride in aqueous solutions undergoes hydrolysis slowly that results in the formation of p-butylaminobenzoic acid crystals. Solutions containing crystals should not be used.4; 3737; 3738
Tetracaine hydrochloride stability in aqueous solution was evaluated. Accelerated degradation at elevated temperatures led to a determination that tetracaine hydrochloride in aqueous solution was stable for at least 12 months at 25°C with about 96% remaining. After two years, the concentration had declined to about 89%.2453 When stored under refrigeration at 4 to 6°C, no loss of tetracaine hydrochloride was detected after 365 days of storage.2705
Autoclaving
Intact vials or ampuls of tetracaine hydrochloride injection can be autoclaved at 121°C for 15 minutes to sterilize the exterior of the containers.3737; 3738 However, autoclaving may increase the occurrence of crystal formation.3737; 3738 Ampuls that have been autoclaved but are not used must be discarded and may not be returned to stock.3737; 3738
pH Effects
Tetracaine hydrochloride is unstable in both acidic and alkaline media. The pH of maximum stability was found to be 3.8.2666; 2705 Tetracaine hydrochloride mixed with alkali hydroxides or carbonates results in the precipitation of tetracaine base as an oily liquid.4
For a list of references cited in the text of this monograph, search the monograph titled References.