Tetracaine Hydrochloride in Dextrose Injection
» Tetracaine Hydrochloride in Dextrose Injection is a sterile solution of Tetracaine Hydrochloride and Dextrose in Water for Injection. It contains not less than 95.0 percent and not more than 105.0 percent of the labeled amounts of tetracaine hydrochloride (C15H24N2O2·HCl) and dextrose (C6H12O6).
Packaging and storage Preserve in single-dose or multiple-dose containers, preferably of Type I glass, under refrigeration and protected from light. It may be packaged in 100-mL multiple-dose containers. Injection supplied as a component of spinal anesthesia trays may be stored at room temperature for 12 months.
Labeling Label it to indicate that the Injection is not to be used if it contains crystals, or if it is cloudy or discolored.
USP Reference standards 11
USP Endotoxin RS
A: Ultraviolet Absorption 197U: Assay preparation, compared to the Standard preparation from the Assay.
B: It responds to Identification test C under Tetracaine Hydrochloride.
C: It responds to the Identification test under Dextrose.
Bacterial endotoxins 85 It contains not more than 1.0 USP Endotoxin Unit per mg of tetracaine hydrochloride.
pH 791: between 3.5 and 6.0
Particulate matter 788: meets the requirements under small-volume injections.
Other requirements It meets the requirements under Injections 1.
Standard preparation Dissolve about 20 mg of USP Tetracaine Hydrochloride RS, accurately weighed, in water to make 100.0 mL, and mix. Pipet 5 mL of this solution into a 100-mL volumetric flask, add 5 mL of dilute hydrochloric acid (1 in 200) and 10 mL of Buffer No. 6, 10 percent, pH 6.0 (see Phosphate Buffers 81), dilute with water to volume, and mix.
Assay preparation Transfer an accurately measured volume of Injection, equivalent to about 10 mg of tetracaine hydrochloride, to a separator, dilute with water to about 50 mL, and render alkaline by the addition of 5 mL of sodium carbonate TS. Extract immediately with two 50-mL portions of ether, collecting the extracts in a separator. Wash the ether extracts with 20 mL of water, discarding the wash solution, and extract the ether solution with two 20-mL portions and one 5-mL portion of dilute hydrochloric acid (1 in 200), collecting the extracts in a 50-mL volumetric flask. Dilute with water to volume, and mix. Transfer a 5.0-mL aliquot to a 100-mL volumetric flask, add 10 mL of Buffer No. 6, 10 percent, pH 6.0 (see Phosphate Buffers and Other Solutions under AntibioticsMicrobial Assays 81), dilute with water to volume, and mix.
Procedure Concomitantly determine the absorbances of the Assay preparation and the Standard preparation at the wavelength of maximum absorbance at about 310 nm, with a suitable spectrophotometer, using water as the blank. Calculate the quantity, in mg, of tetracaine hydrochloride (C15H24N2O2·HCl) in the volume of Injection taken by the formula:
C(AU / AS)in which C is the concentration, in µg per mL, of USP Tetracaine Hydrochloride RS in the Standard preparation; and AU and AS are the absorbances of the Assay preparation and the Standard preparation, respectively.
Assay for dextrose Determine the angular rotation of the Injection in a suitable polarimeter tube (see Optical Rotation 781). Calculate the percentage (g per 100 mL) of dextrose (C6H12O6) in the portion of Injection taken by the formula:
(100/52.9)ARin which 100 is the percentage; 52.9 is the midpoint of the specific rotation range for anhydrous dextrose, in degrees; A is 100 mm divided by the length of the polarimeter tube, in mm; and R is the observed rotation, in degrees.
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USP35NF30 Page 4808Pharmacopeial Forum: Volume No. 30(5) Page 1648