Naphazoline Hydrochloride Ophthalmic Solution
»Naphazoline Hydrochloride Ophthalmic Solution is a sterile,buffered solution of Naphazoline Hydrochloride in water adjusted to a suitable tonicity.It contains not less than 90.0percent and not more than 115.0percent of the labeled amount of Naphazoline Hydrochloride (C14H14N2·HCl).It contains a suitable preservative.
Packaging and storage— Preserve in tight containers.
Identification— Place in a separator a volume of Ophthalmic Solution,equivalent to about 25mg of naphazoline hydrochloride,add 5mLof 1Nsodium hydroxide,saturate with sodium chloride,and extract with two 25-mLportions of ether.Wash the ether solution with 5mLof water,pass the ether through a small paper filter,evaporate the filtrate to about 5mL,transfer the residual solution to a 10-to 15-mLbeaker,allow to evaporate spontaneously,and dry the residue at 80for 1hour:the naphazoline so obtained melts between 115and 120when determined as directed for Class Iaunder Melting Rangeor Temperature á741ñ.
Sterility á71ñ: meets the requirements.
pHá791ñ: between 5.5and 7.0.
Assay—
Phosphate buffer— Transfer 3g of monobasic potassium phosphate to a 1-liter volumetric flask,dissolve in 1000mLof water and 3mLof triethylamine,and mix.Adjust with phosphoric acid to a pHof 3,and mix.
Mobile phase— Prepare a filtered and degassed mixture of Phosphate bufferand acetonitrile (80:20).Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).
Standard preparation— Dissolve an accurately weighed quantity of USP Naphazoline Hydrochloride RSin water,and dilute quantitatively,and stepwise if necessary,with Mobile phaseto obtain a solution having a known concentration of about 0.05mg per mL.
Assay preparation— Transfer an accurately measured volume of Ophthalmic Solution,equivalent to about 5.0mg of naphazoline hydrochloride,to a 100-mLvolumetric flask,dissolve in and dilute with Mobile phaseto volume,and mix.
Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a 285-nm detector and a 4.6-mm ×15-cm column that contains packing L11.The flow rate is about 1.5mLper minute.The column temperature is maintained at 40.Chromatograph the Standard preparation,and record the peak responses as directed under Procedure:the column efficiency is not less than 5000theoretical plates,the tailing factor is not more than 2.0,and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure— Separately inject equal volumes (about 10µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of C14H14N2·HCl in the portion of Ophthalmic Solution taken by the formula:
100C(rU/rS),
in which Cis the concentration,in mg per mL,of USP Naphazoline Hydrochloride RSin the Standard preparation,and rUand rSare the peak responses obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist
Expert Committee:(PA6)Pharmaceutical Analysis 6
USP28–NF23Page 1334
Phone Number:1-301-816-8389
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