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.
USP Reference standards 
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11—
USP Physostigmine Salicylate RS 
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Identification—
It responds to the Identification tests under Physostigmine Salicylate.
Sterility 71:
meets the requirements.
71:
meets the requirements.
pH 791:
between 2.0 and 4.0.
791:
between 2.0 and 4.0.
Assay—
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%.
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 | Hariram Ramanathan, M.S.
Associate Scientific Liaison 1-301-816-8313 |
(SM42010) Monographs - Small Molecules 4 |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
|
| 71 |
Radhakrishna S Tirumalai, Ph.D.
Principal Scientific Liaison 1-301-816-8339 |
(GCM2010) General Chapters - Microbiology |
USP35–NF30 Page 4317