K. Ruckmani¹, Saleem Z. Shaikh^1,, Pavne Khalil², Aamer Khatri², Javed Akmal²

A new, simple, rapid and reliable turbidimetric routine method for the determination of sodium hyaluronate in active pharmaceutical ingredient and ophthalmic solution is described by using DP5 Phototrode. The turbidity of an aqueous ophthalmic sample solution was measured using a DP5 Phototrode™ for photometric indicated titration. Near the equivalence point, a precipitate between titrant and analyte is formed, and the solution becomes turbid. The method involves measurement of the equivalence point at minimum light transmission through the sample, containing cationic quaternary ammonium compound, cetylpyridinium chloride (CPC) solution as a dispersing agent, is measured at 520 nm. The results obtained for in-house prepared formulation and other marketed ophthalmic solution are compared with those obtained by the published HPLC method. A calibration curve was obtained from 0.08 to 0.122 mg mL–1 (r > 0.9998). Within-day % RSD was 1.08 and between-day % RSD was 1.10. Specificity/ selectivity experiments revealed the absence of interference from excipients, recovery from spiked samples for sodium hyaluronate was 98.3–100.9%. The developed method was applied to the determination of sodium hyaluronate in pharmaceutical drug substance and drug product.

sodium hyaluronate, hyaluronic acid, ophthalmic solution, turbidimetric, Phototrode