Physostigmine Salicylate Ophthalmic Solution
» Physostigmine Salicylate Ophthalmic Solution is a sterile, aqueous solution of Physostigmine Salicylate. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of C15H21N3O2·C7H6O3. It may contain suitable antimicrobial agents, buffers, and stabilizers, and suitable additives to increase its viscosity.
Packaging and storage— Preserve in tight, light-resistant containers.
Identification— It responds to the Identification tests under Physostigmine Salicylate.
Sterility 71: meets the requirements.
pH 791: between 2.0 and 4.0.
0.05 M Ammonium acetate and Mobile phase Prepare as directed in the Assay under Physostigmine Salicylate Injection.
Standard preparation— Dissolve an accurately weighed quantity of USP Physostigmine Salicylate RS in acetonitrile, and dilute quantitatively, and stepwise if necessary, with acetonitrile, to obtain a solution having a known concentration of about 30 µg per mL.
Assay preparation— Transfer an accurately measured volume of Ophthalmic Solution, equivalent to about 3 mg of physostigmine salicylate, to a 100-mL volumetric flask, dilute with acetonitrile to volume, and mix.
Chromatographic system (see Chromatography 621)—The liquid chromatograph is equipped with a 254-nm detector and a 3.9-mm × 30-cm column that contains packing L1. The flow rate is about 2 mL per minute. Chromatograph the Standard preparation and record the peak responses as directed for Procedure: the column efficiency determined from the analyte peak is not less than 1200 theoretical plates, and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure— Proceed as directed for Procedure in the Assay under Physostigmine Salicylate Injection. Calculate the quantity, in mg, of C15H21N3O2·C7H6O3 in each mL of the Ophthalmic Solution taken by the formula:
0.1(C / V)(rU / rS)
in which the terms are as defined therein.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Ravi Ravichandran, Ph.D.
Senior Scientist
(MDPP05) Monograph Development-Psychiatrics and Psychoactives
Reference Standards Lili Wang, Technical Services Scientist
71 Radhakrishna S Tirumalai, Ph.D.
Senior Scientist
(MSA05) Microbiology and Sterility Assurance
USP32–NF27 Page 3301
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.