Dyclonine Hydrochloride Gel
» Dyclonine Hydrochloride Gel contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of C18H27NO2·HCl. It may contain suitable stabilizers and antimicrobial agents.
Packaging and storage Preserve in collapsible, opaque plastic tubes or in tight, light-resistant glass containers. [noteDo not use aluminum or tin tubes. ]
USP Reference standards 11
Identification Shake a portion of Gel, equivalent to about 400 mg of dyclonine hydrochloride, with 25 mL of chloroform, and allow the layers to separate. Remove the chloroform layer, evaporate on a steam bath to dryness, and dry the residue at 105 for 1 hour: the dyclonine hydrochloride so obtained responds to the Identification tests under Dyclonine Hydrochloride.
pH 791: between 2.0 and 4.0.
Mobile phase Dissolve 0.20 g of monobasic potassium phosphate and 0.45 mL of n-heptylamine in about 350 mL of water. Adjust with phosphoric acid to a pH of 3.0, dilute with water to 400 mL, add 600 mL of acetonitrile, and mix.
Standard preparation Dissolve an accurately weighed quantity of USP Dyclonine Hydrochloride RS in 0.001 N phosphoric acid to obtain a solution having a known concentration of about 0.1 mg per mL.
Assay preparation Transfer an accurately measured portion of Gel, equivalent to about 5.0 mg of dyclonine hydrochloride, to a 50-mL volumetric flask. Add 10 mL of 0.001 N phosphoric acid, and sonicate to dissolve the gel. Dilute with 0.001 N phosphoric acid to volume, and mix.
Chromatographic system (see Chromatography 621)The liquid chromatograph is equipped with a 254-nm detector and a 4-mm × 25-cm column that contains 5-µm diameter packing L13. The flow rate is about 1.2 mL per minute. Adjust the flow rate, if necessary, so that the retention time of dyclonine hydrochloride is not less than 5 minutes. Chromatograph five replicate injections of the Standard preparation, and record the peak responses as directed for Procedure: the tailing factor is not more than 2.0 and the relative standard deviation is not more than 3.0%.
Procedure Separately inject equal volumes (about 20 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of dyclonine hydrochloride (C18H27NO2·HCl) in the portion of Gel taken by the formula:
50C(rU / rS)in which C is the concentration, in mg per mL, of USP Dyclonine Hydrochloride RS in the Standard preparation, and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
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USP35NF30 Page 2997