Tropicamide Ophthalmic Solution

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

DOWNLOAD PDF HERE

1 DEFINITION

Tropicamide Ophthalmic Solution is a sterile, aqueous solution of Tropicamide. It contains NLT 95.0% and NMT 105.0% of the labeled amount of tropicamide (C₁₇H₂₀N₂O₂). It contains a suitable antimicrobial agent, and may contain suitable substances to increase its viscosity.

2 IDENTIFICATION

Change to read:

A. SPECTROSCOPIC IDENTIFICATION TESTS (197), Infrared Spectroscopy: 197K (CN 1-MAY-2020)

Sample: Extract 10 mL of Ophthalmic Solution with 25 mL of chloroform, pass the chloroform extract through dry, folded filter paper, and evaporate the filtrate to dryness.

Acceptance criteria: The residue so obtained meets the requirements.

B. The UV absorption spectrum of the solution used for measurement of absorbance in the Assay exhibits maxima and minima at the same wavelengths as that of a similar solution of USP Tropicamide RS, concomitantly measured.

3 ASSAY

PROCEDURE

Standard solution: 30 µg/mL of USP Tropicamide RS in dilute sulfuric acid (1 in 6)

Sample solution: Transfer a volume of Ophthalmic Solution, nominally equivalent to 30 mg of tropicamide, to a 100-mL volumetric flask, and add water to volume. Transfer 10.0 mL of this solution to a separator, add 2 mL of sodium carbonate solution (1 in 10), extract with four 20-ml portions of chloroform, and combine the extracts in a second separator. Wash the combined extracts with a 25-mL portion of pH 6.5 phosphate buffer (see Reagents, Indicators, and Solutions-Buffer Solutions), and transfer to another separator. Wash the aqueous layer with 10 mL of chloroform, and add it to the extracts. Extract the chloroform solution with four 20-mL portions of dilute sulfuric acid (1 in 6), combine the acid extracts in a 100-mL volumetric flask, and add the dilute acid to volume.

Instrumental conditions

Mode: UV

Analytical wavelength: At the wavelength of maximum absorbance at about 253 nm

Cell: 1 cm

Blank: Dilute sulfuric acid (1 in 6)

Analysis

Samples: Standard solution, Sample solution, and Blank

Calculate the percentage of the labeled amount of tropicamide (C₁₇H₂₀N₂O₂) in the portion of Ophthalmic Solution taken:

Result = (A_u /A_s ) × (C_s /C_u ) × 100

A_u = absorbance of the Sample solution

A_s = absorbance of the Standard solution

C_s = concentration of USP Tropicamide RS in the Standard solution (µg/mL)

C_u = nominal concentration of tropicamide in the Sample solution (µg/mL)

Acceptance criteria: 95.0%–105.0%

4 SPECIFIC TESTS

Sterility Tests 〈71〉: Meets the requirements

pH 〈791〉: 4.0–5.8

5 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers, and avoid freezing.

USP Reference Standards 〈11〉

USP Tropicamide RS