Hydroxypropyl Cellulose Ocular System

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

Hydroxypropyl Cellulose Ocular System contains NLT 85.0% and NMT 115.0% of the labeled amount of Hydroxypropyl Cellulose. It contains no other substance. It is sterile.

2 IDENTIFICATION

2.1 INFRARED ABSORPTION

Sample solution: A 10-mg/mL solution in methanol, based on the labeled amount of Hydroxypropyl Cellulose. Evaporate 2 drops of the solution on a silver chloride plate so that it forms a thin film.

Acceptance criteria: The infrared absorption spectrum of the film exhibits maxima only at the same wavelengths as that of a similar preparation of USP Hydroxypropyl Cellulose RS.

3 ASSAY

3.1 PROCEDURE

Standard stock solution: 0.25 mg/mL of USP Hydroxypropyl Cellulose RS prepared as follows: Weigh 25 mg of USP Hydroxypropyl Cellulose RS into a 100-mL volumetric flask. Dissolve in 80 mL of water. Mix well by agitating on a mechanical shaker until completely dissolved. Add one drop of methanol to dispel the foam and dilute with water to volume. [NOTE-Stirring overnight before diluting to volume is recommended.]

Standard solution: 0.05 mg/mL of hydroxypropyl cellulose in water, from Standard stock solution

Sample stock solution: 0.25 mg/mL of hydroxypropyl cellulose prepared using the same procedure as the Standard stock solution

Sample solution: 0.05 mg/mL of hydroxypropyl cellulose in water, from Sample stock solution

Spectrometric conditions

(See Ultraviolet-Visible Spectroscopy (857).)

Mode: UV-Vis

Analytical wavelength: 620 nm

Cell length: 1.0 cm, quartz

Analysis

Samples: Standard solution and Sample solution

Separately pipet 2 mL of the Standard solution, the Sample solution, and water, to provide a blank, into individual 50-mL centrifuge tubes. Add to each tube, 6.0 mL of a 0.5 mg/mL solution of anthrone in sulfuric acid, and mix on a vortex mixer. Let the centrifuge tubes cool for approximately 40 min and remix. Concomitantly determine the absorbances of the Standard solution and the Sample solution. [NOTE -Prepare anthrone in sulfuric acid solution just before use in low-actinic glassware, and mix well before adding to the tube. Use it within 12 h of preparation. Avoid contact between the glassware and the paper products during analysis; the cellulose in the paper will react with the sulfuric acid and alter the results.]

Calculate the percentage of hydroxypropyl cellulose in the Ocular System:

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 the Standard solution (mg/mL)

C_U = nominal concentration of hydroxypropyl cellulose in the Sample solution (mg/mL)

Acceptance criteria: 85.0%-115.0%

4 PERFORMANCE TESTS

4.1 WEIGHT VARIATION

Analysis: Determine the weight of each of a sufficient number of Systems.

Acceptance criteria: NMT 1 out of 20 Systems varies more than 25% from the average or, failing that, NMT 6 out of 60 (including the original 20) vary more than 25% (but none more than 35%) from the average weight.

5 SPECIFIC TESTS

STERILITY TESTS (71): Meets the requirements

6 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in single-dose containers, at a temperature not exceeding 30°.

USP REFERENCE STANDARDS (11)

USP Hydroxypropyl Cellulose RS