» Simethicone Emulsion is a water-dispersible form of Simethicone composed of Simethicone, suitable emulsifiers, preservatives, and water. It may contain suitable viscosity-increasing agents. It contains an amount of polydimethylsiloxane ([(CH3)2SiO]n) that is not less than 85.0 percent and not more than 110.0 percent of the labeled amount of simethicone.
Packaging and storage Preserve in tight containers.
Identification The IR absorption spectrum, determined in a 0.5-mm cell, of the solution of Emulsion prepared as directed in the Assay, exhibits maxima only at the same wavelengths as that of a similar preparation of USP Polydimethylsiloxane RS. If necessary, the dilute hydrochloric acid may be omitted to improve separation. [notePrepare a procedural blank by similarly treating 25.0 mL of toluene, and use this blank to set the instrument.]
Microbial enumeration tests 61 and Tests for specified microorganisms 62 Its total aerobic microbial count does not exceed 100 cfu per g.
Heavy metals Using Simethicone Emulsion instead of Simethicone, proceed as directed for Heavy metals under Simethicone. The limit is 5 µg per g.
Foaming solution Dissolve 1 g of octoxynol 9 in 100 mL of water.
Test preparation Transfer an accurately weighed quantity of Emulsion, equivalent to 300 mg of simethicone, to a 60-mL bottle, dilute with water to 30 g, cap the bottle, and shake vigorously.
Procedure Proceed as directed for Procedure in the test for Defoaming activity under Simethicone. The defoaming activity time does not exceed 15 seconds.
Assay Transfer an accurately weighed quantity of Emulsion, equivalent to about 50 mg of simethicone, to a round, narrow-mouth, screw-capped, 120-mL bottle, add 25.0 mL of toluene, and swirl to disperse. Proceed as directed in the Assay under Simethicone, beginning with Add 50 mL of dilute hydrochloric acid. Calculate the quantity, in mg, of [(CH3)2SiO]n in each g of the Emulsion taken by the formula:
(25C/S)(AU / AS)in which C is the concentration, in mg per mL, of USP Polydimethylsiloxane RS in the Standard preparation; S is the weight, in g, of Emulsion taken; and AU and AS are the absorbances of the Assay preparation and the Standard preparation, respectively.
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USP32NF27 Page 3555Pharmacopeial Forum: Volume No. 34(3) Page 652