Cefixime for Oral Suspension
DEFINITION
Cefixime for Oral Suspension is a dry mixture of Cefixime and one or more suitable diluents, flavors, preservatives, and suspending agents. It contains the equivalent of NLT 90.0% and NMT 120.0% of the labeled amount of cefixime (C16H15N5O7S2)/mL when constituted as directed in the labeling.
IDENTIFICATION
• The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.
ASSAY
• Procedure
Solution A:
0.4 M tetrabutylammonium hydroxide solution and water (1:39). Adjust with 1.5 M phosphoric acid to a pH of 6.5.
Solution B:
13.6 mg/mL of monobasic potassium phosphate
Solution C:
14.2 mg/mL of anhydrous dibasic sodium phosphate. Adjust a volume of this solution with a sufficient volume of Solution B to a pH of 7.0.
Mobile phase:
Acetonitrile and Solution A (1:3)
System suitability solution:
1 mg/mL of USP Cefixime RS. [Note—Heat this solution at 95
in an oil bath for 45 min, cool, and use promptly. ]
in an oil bath for 45 min, cool, and use promptly. ]
Standard solution:
0.2 mg/mL of USP Cefixime RS in Solution C. [Note—Use this solution promptly. ]
Sample solution:
Constitute Cefixime for Oral Suspension as directed in the labeling. Quantitatively dilute a suitable aliquot of the suspension, freshly mixed and free from air bubbles, with Solution C to obtain a solution having a nominal concentration of 0.2 mg of cefixime/mL.
Chromatographic system
Mode:
LC
Detector:
UV 254 nm
Column:
4.6-mm × 12.5-cm; 4-µm packing L1
Temperature:
40
Flow rate:
Adjust flow rate so that the retention time of cefexime is about 10 min.
Injection size:
10 µL
System suitability
Samples:
System suitability solution and Standard solution
[Note—The relative retention times for cefixime (E)-isomer and cefixime are about 0.9 and 1.0, respectively. ]
Suitability requirements
Resolution:
NLT 2.0 between cefixime and cefixime (E)-isomer, System suitability solution
Column efficiency:
NLT 4000 theoretical plates, Standard solution. Use the following formula to calculate column efficiency:
Result = 5.545(t/Wh/2)2
Tailing factor:
NLT 0.9 and NMT 2.0 for the analyte peak, Standard solution. Use the following formula to calculate tailing factor:
Result = W0.1/2f
| W0.1 | = | = peak width at 10% peak height |
Relative standard deviation:
NMT 2.0%, Standard solution
Analysis
Samples:
Standard solution and Sample solution
Calculate the percentage of C16H15N5O7S2 in the constituted suspension prepared from the Cefixime for Oral Suspension:
Result = (rU/rS) × (CS/CU) × 100
| rU | = | = peak response of cefixime from the Sample solution |
| rS | = | = peak response of cefixime from the Standard solution |
| CS | = | = concentration of USP Cefixime RS in the Standard solution (mg/mL) |
| CU | = | = nominal concentration of cefixime in the Sample solution (mg/mL) |
Acceptance criteria:
90.0%–120.0%
PERFORMANCE TESTS
• Uniformity of Dosage Units 
905
FOR SOLIDS PACKAGED IN SINGLE-UNIT CONTAINERS:
Meets the requirements
905 FOR SOLIDS PACKAGED IN SINGLE-UNIT CONTAINERS:
Meets the requirements
• Deliverable Volume 698:
Meets the requirements
698:
Meets the requirements
SPECIFIC TESTS
• pH 791:
2.5–4.5, in the suspension constituted as directed in the labeling
791:
2.5–4.5, in the suspension constituted as directed in the labeling
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in tight containers.
• Labeling:
Label it to indicate that the cefixime contained therein is in the trihydrate form.
• USP Reference Standards 11
11
USP Cefixime RS 
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Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Ahalya Wise, M.S.
Senior Scientific Liaison 1-301-816-8161 |
(SM12010) Monographs - Small Molecules 1 |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
USP35–NF30 Page 2548
Pharmacopeial Forum: Volume No. 34(6) Page 1441