Clopidogrel Compounded Oral Suspension
DEFINITION
Clopidogrel Compounded Oral Suspension contains NLT 90.0% and NMT 110.0% of the labeled amount of clopidogrel (C16H16ClNO2S).
Prepare Clopidogrel Compounded Oral Suspension 5 mg/mL as follows (see Pharmaceutical Compounding—Nonsterile Preparations 795).
Clopidogrel tablet(s)a equivalent to 525 mg
Vehicle: A 1:1 mixture of Ora-Plusb and Ora-Sweetb, a sufficient quantity to make 105 mL
a   Clopidogrel 75-mg tablets, Dr. Reddy's Laboratory Limited, Bridgewater, NJ.
b   Perrigo Pharmaceuticals, Allegan, MI.
Crush the Clopidogrel tablet(s) to a fine powder using a mortar and pestle or by other mechanical means. Wet the powder with a small amount of Vehicle, and triturate to make a smooth paste. Add the Vehicle to make the contents pourable. Transfer the contents stepwise and quantitatively to a calibrated container using the remainder of the Vehicle. Add sufficient Vehicle to bring to final volume. Shake to mix well.
ASSAY
•  Procedure
Solution A:  10 mM sodium phosphate adjusted with phosphoric acid to a pH of 3.0. Pass through a nylon filter of 0.45-µm pore size, and degas.
Mobile phase:  Acetonitrile and Solution A (65:35)
Diluent:  Water adjusted with phosphoric acid to a pH of 3.0
Standard stock solution:  5 mg/mL of clopidogrel prepared from USP Clopidogrel Bisulfate RS and Diluent. Mix well, and sonicate for 3 min. Store at 2–8.
Standard solution:  Transfer 2.0 mL of the Standard stock solution to a 1-L volumetric flask, and dilute with Diluent to volume. Mix well, centrifuge a portion of the solution for 5 min at 14,000 rpm, and use the supernatant. Protect from light, and store at 2–8.
Sample solution:  Shake each bottle of Oral Suspension thoroughly. Transfer 2.0 mL of the Oral Suspension to a 1-L volumetric flask, and dilute with Diluent to volume. Mix well, centrifuge a portion of the solution for 5 min at 14,000 rpm, and use the supernatant. Protect from light, and store at 2–8.
Chromatographic system 
Mode:  LC
Detector:  UV 235 nm
Column:  2.1-mm × 25-cm; 5-µm packing L7
Temperatures 
Column:  35
Autosampler:  5
Flow rate:  0.3 mL/min
Injection volume:  20 µL
System suitability 
Sample:  Standard solution
[Note—The retention time for clopidogrel is about 7.4 min. ]
Suitability requirements 
Tailing factor:  NMT 2.0
Relative standard deviation:  NMT 2.0% for replicate injections
Analysis 
Samples:  Standard solution and Sample solution
Calculate the percentage of the labeled amount of clopidogrel (C16H16ClNO2S) in the portion of Oral Suspension taken:
Result = (rU/rS) × (CS/CU) × 100

rU== peak response of clopidogrel from the Sample solution
rS== peak response of clopidogrel from the Standard solution
CS== concentration of clopidogrel in the Standard solution (mg/mL)
CU== nominal concentration of clopidogrel in the Sample solution (mg/mL)
Acceptance criteria:  90.0%–110.0%
SPECIFIC TESTS
•  pH 791: 2.1–3.1
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Package in tight, light-resistant containers. Store at 2–8 or at controlled room temperature.
•  Labeling: Label it to indicate that it is to be well shaken before use, and to state the Beyond-Use Date.
•  Beyond-Use Date: NMT 90 days after the date on which it was compounded, when stored at 2–8 or at controlled room temperature
•  USP Reference Standards 11
USP Clopidogrel Bisulfate RS Click to View Structure
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Jeanne H. Sun, Pharm.D.
Associate Scientific Liaison
(301) 230-3361
(CMP2010) Compounding
Reference Standards RS Technical Services
1-301-816-8129
rstech@usp.org
USP38–NF33 Page 2901
Pharmacopeial Forum: Volume No. 39(5)