Cilostazol Tablets
DEFINITION
Cilostazol Tablets contain NLT 90.0% and NMT 110.0% of the labeled amount of cilostazol (C20H27N5O2).
IDENTIFICATION
Standard solution:  100 mg/mL of USP Cilostazol RS in chloroform
Sample solution:  Transfer the equivalent of 100 mg of cilostazol from finely powdered Tablets into a glass container. Add 1 mL of chloroform, shake for 1 min, and pass through a suitable filter of 0.5-µm or finer pore size.
•  B. The retention time of the cilostazol peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.
ASSAY
•  Procedure
Mobile phase:  Acetonitrile, methanol, and water (7:3:10)
Internal standard solution:  4 mg/mL of benzophenone in methanol
Standard solution:  0.1 mg/mL of USP Cilostazol RS and 0.04 mg/mL of Internal standard solution in methanol
Sample solution:  Transfer the equivalent of 50 mg of cilostazol from powdered Tablets (NLT 20) into a suitable volumetric flask and add an appropriate quantity of Internal standard solution. Dilute with methanol to obtain a solution of 0.1 mg/mL of USP Cilostazol RS and 0.04 mg/mL of the internal standard. Pass a portion of this solution through a membrane filter of 0.5-µm or finer pore size, and use the filtrate.
Chromatographic system
Mode:  LC
Detector:  UV 254 nm
Column:  4.6-mm × 15-cm; packing L1
Flow rate:  1 mL/min
Injection size:  10 µL
System suitability
Sample:  Standard solution
Suitability requirements
Resolution:  NLT 9.0 between the cilostazol and benzophenone peaks, eluted in this order
Relative standard deviation:  NMT 1.5%
Analysis
Samples:  Standard solution and Sample solution
Calculate the percentage of the labeled amount of cilostazol (C20H27N5O2) in the portion of Tablets taken:
Result = (RU/RS) × (CS/CU) × 100
 RU = = peak response ratio of cilostazol to the internal standard from the Sample solution RS = = peak response ratio of cilostazol to the internal standard from the Standard solution CS = = concentration of USP Cilostazol RS in the Standard solution (mg/mL) CU = = nominal concentration of cilostazol in the Sample solution (mg/mL)
Acceptance criteria:  90.0%–110.0%
PERFORMANCE TESTS
Test 1
Medium:  0.30% sodium lauryl sulfate in water; 900 mL
Apparatus 2:  75 rpm
Time:  60 min
Standard solution:  0.28 mg of USP Cilostazol RS in methanol. Dilute this solution with Medium to obtain a solution with a final concentration of about 56 µg/mL.
Sample solution:  Pass NLT 20 mL of the solution under test through a suitable filter of 0.45-µm pore size, discarding the first 10 mL. Dilute with Medium to obtain a final theoretical concentration of about 56 µg/mL, considering complete dissolution of the label claim.
Wavelength:  UV 257 nm
Path length:  1 cm
Blank:  Medium
Calculate the percentage of cilostazol dissolved:
Result = (AU/AS) × (CS/L) × V × 100
 AU = = absorbance of the Sample solution AS = = absorbance of the Standard solution CS = = concentration of the Standard solution (mg/mL) L = = Tablet label claim V = = volume of Medium, 900 mL
Tolerances:  NLT 80% (Q) of the labeled amount of cilostazol is dissolved.
Test 2:  If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 2.
Medium:  0.3% sodium lauryl sulfate in water; 900 mL, deaerated
Apparatus 2:  75 rpm
Time:   30 min
Standard solution:  Prepare a solution containing 1.1 mg/mL of USP Cilostazol RS in methanol. Dilute this solution with 0.5% sodium lauryl sulfate in water to obtain a final concentration of (L/900) mg/mL, where L is the Tablet label claim in mg.
Sample solution:  Pass a portion of the solution under test through a suitable filter.
Wavelength:  UV 258 nm
Path length:  0.2 cm
Blank:  Medium
Tolerances:  NLT 75% (Q) of the labeled amount of cilostazol is dissolved.
Test 3:  If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 3.
Medium:  0.3% sodium lauryl sulfate in water; 900 mL
Apparatus 2:  75 rpm
Time:   60 min
Standard solution, Sample solution, Wavelength, Path length, and Blank:  Proceed as directed for Test 1.
Tolerances:  NLT 70% (Q) of the labeled amount of cilostazol is dissolved.
Meet the requirements
•  Packaging and Storage: Preserve in tight and light-resistant containers. Store at controlled room temperature.
•  Labeling: When more than one Dissolution test is given, the labeling states the Dissolution test used only if Test 1 is not used.
USP Cilostazol RS
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Sujatha Ramakrishna, Ph.D.
Senior Scientific Liaison
1-301-816-8349
(SM22010) Monographs - Small Molecules 2
711 Margareth R.C. Marques, Ph.D.
Senior Scientific Liaison
1-301-816-8106
(GCDF2010) General Chapters - Dosage Forms
Reference Standards RS Technical Services
1-301-816-8129
rstech@usp.org
USP35–NF30 Page 2664
Pharmacopeial Forum: Volume No. 33(3) Page 395