Chlorhexidine Gluconate Oral Rinse
» Chlorhexidine Gluconate Oral Rinse is prepared from Chlorhexidine Gluconate Solution. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of chlorhexidine gluconate (C22H30Cl2N10·2C6H12O7).
Packaging and storage Preserve in tight containers, protected from light, at controlled room temperature.
Labeling Oral Rinse intended solely for veterinary use is so labeled. Oral Rinse intended for human use is labeled to indicate it is to be expectorated and not swallowed after rinsing.
USP Reference standards 11
USP Chlorhexidine Acetate RS
USP p-Chloroaniline RS
A: The retention time of the major peak for chlorhexidine in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.
B: To a volume of Oral Rinse, equivalent to about 10 mg of chlorhexidine gluconate, add 5 mL of a solution of cetyltrimethylammonium bromide (1 in 100), 1 mL of 10 N sodium hydroxide, and 1 mL of bromine TS: a deep red color is produced.
C: Undiluted Oral Rinse used as the test solution meets the requirements for Identification test B under Calcium Gluconate, except that a Standard solution containing about 0.6 mg of USP Potassium Gluconate RS per mL is used and 15 µL of the test solution and the Standard solution are applied to the thin-layer chromatographic plate.
pH 791: between 5.0 and 7.0.
Limit of p-chloroaniline
Solution A, Solution B, Mobile phase, Diluent, System suitability solution, and Chromatographic system Proceed as directed in the Assay under Chlorhexidine Gluconate Solution.
Standard solutions Prepare as directed for Standard solutions in the test for Limit of p-chloroaniline under Chlorhexidine Gluconate Solution.
Test solution Transfer 10.0 mL of Oral Rinse to a 25-mL volumetric flask, dilute with Diluent to volume, and mix.
Procedure Proceed as directed in the test for Limit of p-chloroaniline under Chlorhexidine Gluconate Solution. Calculate the quantity, in µg per mL, of p-chloroaniline in the Oral Rinse taken by the formula:
2.5C.The limit is 3.0 µg per mL.
Content of alcohol
Internal standard solution Dilute 25 mL of n-propyl alcohol with water to 500 mL.
Standard solution Transfer about 0.25 g of dehydrated alcohol, accurately weighed, to a 28-mL screw capped vial containing about 3 mL of water. Add 5.0 mL of Internal standard solution, and dilute with water to almost fill the vial. Cap the vial, and using a vortex mixer, mix for 15 seconds.
Test solution Transfer about 2.5 g of Oral Rinse, accurately weighed, to a 28-mL screw-capped vial. Add 5.0 mL of Internal standard solution, and dilute with water to almost fill the vial. Cap the vial, and using a vortex mixer, mix for 15 seconds.
Chromatographic system (see Chromatography 621) The gas chromatograph is equipped with a flame-ionization detector and a 0.53-mm × 30-m column, the internal wall of which is coated with a 1.5-µm film of liquid phase G27. The column is maintained at about 150 between periods of use. The injection port is equipped with a split injection port with a split ratio of 10:1. The injection port and the detector block temperatures are maintained at about 250 and 275, respectively. At the time of use the initial column temperature is maintained at about 35 until the alcohol peaks elute, then is increased at a rate of 30 per minute to a final temperature of about 225. The carrier gas is helium. Chromatograph the Standard solution, and record the peak responses as directed for Procedure: the relative retention times are 1.0 for alcohol and about 1.5 for n-propyl alcohol; the resolution, R, between alcohol and n-propyl alcohol is not less than 2; the tailing factor for the alcohol peak is not more than 3.0; and the relative standard deviation for replicate injections is not more than 2%.
Procedure Separately inject equal volumes (about 0.5 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the percentage of alcohol (C2H5OH) in the Oral Rinse taken by the formula:
(WS / WU)(RU / RS)in which WS is the weight, in g, of dehydrated alcohol taken to prepare the Standard solution; WU is the weight, in g, of Oral Rinse taken to prepare the Test solution; and RU and RS are the peak response ratios of alcohol to n-propyl alcohol obtained from the Test solution and the Standard solution, respectively: between 90.0% and 115.0% of the labeled amount of alcohol (C2H5OH) is found.
Diluent, Solution A, Solution B, Mobile phase, System suitability solution, Standard preparation, and Chromatographic system Proceed as directed in the Assay under Chlorhexidine Gluconate Solution.
Assay preparation Transfer 5.0 mL of Oral Rinse to a 100-mL volumetric flask, dilute with Diluent to volume, and mix.
Procedure Proceed as directed in the Assay under Chlorhexidine Gluconate Solution. Calculate the percentage (w/v) of chlorhexidine gluconate (C22H30Cl2N10·2C6H12O7) in the portion of Oral Rinse taken by the formula:
(897.76/625.55)(C/500)(rU / rS)in which the terms are as defined therein.
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USP35NF30 Page 2623Pharmacopeial Forum: Volume No. 34(2) Page 250