Mycophenolate Mofetil Capsules
DEFINITION
Mycophenolate Mofetil Capsules contain NLT 90.0% and NMT 110.0% of the labeled amount of mycophenolate mofetil (C23H31NO7).
IDENTIFICATION
•  A. Ultraviolet Absorption 197U
Standard solution and Sample solution:  Use the Standard solution and Sample solution as prepared in the Dissolution test.
Acceptance criteria:  The UV absorption spectra of the Standard solution and the Sample solution exhibit maxima and minima at the same wavelength within ±3 nm.
•  B. 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
Phosphoric acid solution:  Phosphoric acid and water (3:50)
Triethylamine solution:  Transfer 3 mL of triethylamine to 1000 mL of water. Adjust with Phosphoric acid solution to a pH of 5.3.
Mobile phase:  Acetonitrile and Triethylamine solution (11:9)
Standard solution:  0.125 mg/mL of USP Mycophenolate Mofetil RS in acetonitrile
Sample solution:  Open Capsules, equivalent to 1.25 g of mycophenolate mofetil based on the label claim, and transfer the contents including Capsule shells into a 500-mL volumetric flask. Add 50 mL of water, and shake mechanically for a minimum of 15 min. Add 350 mL of acetonitrile, sonicate for 15 min, and shake mechanically for 20 min. Dilute with acetonitrile to volume. Transfer 5.0 mL of this solution to a 100-mL volumetric flask, and dilute with acetonitrile to volume. Pass through a nylon filter of 0.45-µm pore size, and discard the first 5 mL of the filtrate.
Chromatographic system 
Mode:  LC
Detector:  UV 250 nm
Column:  4.6-mm × 25-cm; 5-µm packing L7
Temperature 
Column:  45
Autosampler:  10 ± 5
Flow rate:  1.5 mL/min
Injection size:  20 µL
System suitability 
Sample:  Standard solution
Suitability requirements 
Tailing factor:  NMT 2
Relative standard deviation:  NMT 2.0%
Analysis 
Samples:  Standard solution and Sample solution
Calculate the percentage of the labeled amount of mycophenolate mofetil (C23H31NO7) in the portion of Capsules taken:
Result = (rU/rS) × (CS/CU) × 100
rU== peak response from the Sample solution
rS== peak response from the Standard solution
CS== concentration of mycophenolate mofetil in the Standard solution (mg/mL)
CU== nominal concentration of mycophenolate mofetil in the Sample solution (mg/mL)
Acceptance criteria:  90.0%–110.0%
PERFORMANCE TESTS
•  Dissolution 711
Medium:  0.1 N hydrochloric acid; 900 mL
Apparatus 2:  40 rpm, with sinkers
Time:  20 min
Standard solution:  0.278 mg/mL of USP Mycophenolate Mofetil RS in Medium
Sample solution:  Pass a portion of the solution under test through a suitable filter of 0.45-µm pore size.
Detector:  UV 250 nm
Path length:  0.1 cm
Blank:  Medium
Calculate the percentage of the labeled amount of mycophenolate mofetil (C23H31NO7) 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)
V== volume of Medium, 900 mL
L== label claim (mg/Capsule)
Tolerances:  NLT 80% (Q) of the labeled amount of mycophenolate mofetil (C23H31NO7) is dissolved.
•   Uniformity of Dosage Units 905: Meet the requirements
IMPURITIES
Change to read:
•  Limit of Degradation Products
Mobile phase, Standard solution, Sample solution, and Chromatographic system:  Proceed as directed in the Assay.
Sensitivity solution:  0.0625 µg/mL of USP Mycophenolate Mofetil RS in acetonitrile
System suitability 
Samples:  Standard solution and Sensitivity solution
Suitability requirements 
Signal-to-noise ratio:  NLT 10, Sensitivity solution
Tailing factor:  NMT 2, Standard solution
Relative standard deviation:  NMT 2.0%, Standard solution
Analysis 
[Note—The run time for the Sample solution is three times that of the retention time of the mycophenolate mofetil peak. ]
Samples:  Standard solution and Sample solution
Calculate the percentage of each impurity in the portion of Capsules taken:
Result = (rU/rS) × (CS/CU) × (1/F) × 100
rU== peak response of each individual impurity from the Sample solution
rS== peak response of mycophenolate mofetil from the Standard solution
CS== concentration of USP Mycophenolate Mofetil RS in the Standard solution (mg/mL)
CU== nominal concentration of mycophenolate mofetil in the Sample solution (mg/mL)
F== relative response factor for each individual impurity (see Table 1)
Acceptance criteria 
Individual degradation products:  See Table 1.
[Note—Disregard peaks at relative retention times of 1.45 and 2.15. Disregard any peaks less than 0.05%. ]
Table 1
Name Relative
Retention
Time
Relative
Response
Factor
Acceptance
Criteria,
NMT (%)
Mycophenolic acida 0.6 1.4 1.0(RB 1-May-2011)
Mycophenolate N-oxide analogb 0.8 1.0 0.2
Mycophenolate mofetil 1.0
Any single unspecified impurity 1.0 0.1
Total degradation products 1.5(RB 1-May-2011)
a  (E)-6-(1,3-Dihydro-4-hydroxy-6-methoxy-7-methyl-3-oxo-5-isobenzofuranyl)-4-methyl-4-hexenoic acid.
b  2-Morpholinoethyl (E)-6-(1,3-dihydro-4-hydroxy-6-methoxy-7-methyl-3-oxo-5-isobenzofuranyl)-4-methyl-4-hexenoate N-oxide.
•  Limit of Z-Mycophenolate Mofetil
[Note—Z-Mycophenolate mofetil is 2-morpholinoethyl (Z)-6-(4-hydroxy-6-methoxy-7-methyl-3-oxo-5-phthalanyl)-4-methyl-4-hexenoate. ]
Triethylamine solution:  Proceed as directed in the Assay.
Mobile phase:  Acetonitrile and Triethylamine solution (7:13)
Standard solution:  0.025 mg/mL of USP Mycophenolate Mofetil RS in acetonitrile
Sensitivity solution:  1.25 µg/mL of USP Mycophenolate Mofetil RS in acetonitrile
Sample solution:  Open Capsules, equivalent to 1.25 g of mycophenolate mofetil based on the label claim, and transfer the contents including Capsule shells into a 500-mL volumetric flask. Add 50 mL of water, and shake mechanically for a minimum of 15 min. Add 350 mL of acetonitrile, sonicate for 15 min, and shake mechanically for 20 min. Dilute with acetonitrile to volume. Pass through a nylon filter of 0.45-µm pore size, and discard the first 2 mL of the filtrate.
Chromatographic system 
Mode:  LC
Detector:  UV 215 nm
Column:  4.6-mm × 15-cm; 3.5-µm packing L7
Column temperature:  60
Flow rate:  1.5 mL/min
Injection size:  10 µL
Run time:  1.7 times the retention time of the mycophenolate mofetil peak
System suitability 
Samples:  Standard solution and Sensitivity solution
[Note—The relative retention times for mycophenolate mofetil and Z-mycophenolate mofetil are 1.0 and 1.1, respectively. ]
Suitability requirements 
Signal-to-noise ratio:  NLT 10, Sensitivity solution
Tailing factor:  NMT 2.0, Standard solution
Relative standard deviation:  NMT 5.0%, Standard solution
Analysis 
Samples:  Standard solution and Sample solution
Calculate the percentage of Z-mycophenolate mofetil in the portion of Capsules taken:
Result = (rU/rS) × (CS/CU) × 100
rU== peak response of Z-mycophenolate mofetil from the Sample solution
rS== peak response of mycophenolate mofetil from the Standard solution
CS== concentration of USP Mycophenolate Mofetil RS in the Standard solution (mg/mL)
CU== nominal concentration of mycophenolate mofetil in the Sample solution (mg/mL)
Acceptance criteria 
Z-Mycophenolate mofetil:  NMT 0.10%
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Preserve in well-closed and light-resistant containers, and store at controlled room temperature.
•  USP Reference Standards 11
USP Mycophenolate Mofetil RS Click to View Structure
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Feiwen Mao, M.S.
Senior Scientific Liaison
1-301-816-8320
(SM32010) Monographs - Small Molecules 3
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 3968
Pharmacopeial Forum: Volume No. 35(4) Page 854