» Ampicillin Tablets contain an amount of Ampicillin (anhydrous form or trihydrate form) equivalent to not less than 90.0 percent and not more than 120.0 percent of the labeled amount of ampicillin (C16H19N3O4S).
Packaging and storage Preserve in tight containers, and store at controlled room temperature.
Labeling Label the Tablets to indicate whether the ampicillin therein is in the anhydrous form or is the trihydrate. Label chewable Tablets to indicate that they are to be chewed before swallowing. Tablets intended for veterinary use only are so labeled.
USP Reference standards 11
Identification Powder 1 or more Tablets, and prepare a solution containing 5 mg of ampicillin per mL in a mixture of acetone and 0.1 N hydrochloric acid (4:1): the resulting solution meets the requirements for the Identification test under Ampicillin Capsules.
Dissolution, Procedure for a Pooled Sample 711
Medium: water; 900 mL.
Apparatus 1: 100 rpm.
Time: 45 minutes.
Standard preparation Dissolve an accurately weighed quantity of USP Ampicillin RS in water to obtain a solution having a known concentration of about L/900 mg per mL, L being the labeled amount, in mg, of ampicillin per Tablet.
Procedure Proceed as directed for Procedure in the section AntibioticsHydroxylamine Assay under Automated Methods of Analysis 16, using a filtered portion of the solution under test as the Assay preparation. Calculate the quantity, in mg, of C16H19N3O4S dissolved by the formula:
0.9CP(AU / AS).
Tolerances Not less than 75% (Q) of the labeled amount of C16H19N3O4S is dissolved in 45 minutes.
Uniformity of dosage units 905: meet the requirements.
Water, Method I 921: not more than 4.0% where nonchewable Tablets contain anhydrous Ampicillin; between 9.5% and 12.0% where nonchewable Tablets contain Ampicillin trihydrate; not more than 3.0% where chewable Tablets contain anhydrous Ampicillin; not more than 5.0% where chewable Tablets contain Ampicillin trihydrate; and not more than 13.0% where Tablets are labeled for veterinary use only and contain Ampicillin trihydrate.
Standard preparation Prepare as directed for Standard Preparation under Iodometric AssayAntibiotics 425, using USP Ampicillin RS.
Assay preparation Place not fewer than 5 Tablets in a high-speed glass blender jar containing an accurately measured volume of water, and blend for 4 ± 1 minutes. Dilute an accurately measured volume of this stock solution with water to obtain an Assay preparation containing about 1.25 mg of ampicillin per mL.
Procedure Proceed as directed for Procedure under Iodometric AssayAntibiotics 425. Calculate the quantity, in mg, of ampicillin (C16H19N3O4S) in each Tablet taken by the formula:
(T/D)(F/2000)(B I)in which T is the labeled quantity, in mg, of ampicillin in each Tablet; and D is the concentration, in mg per mL, of ampicillin in the Assay preparation on the basis of the labeled quantity in each Tablet and the extent of dilution.
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USP35NF30 Page 2212Pharmacopeial Forum: Volume No. 30(1) Page 56