Methylphenidate Hydrochloride Tablets
Methylphenidate Hydrochloride Tablets contain NLT 93.0% and NMT 107.0% of the labeled amount of methylphenidate hydrochloride (C14H19NO2·HCl).
•  A. Infrared Absorption 197M
Sample:  Equivalent to 50 mg of methylphenidate hydrochloride from a portion of powdered Tablets in a 40-mL centrifuge tube. Add 10 mL of chloroform, shake, and centrifuge. Filter the clear extract through a medium-sized sintered-glass funnel into a beaker, and repeat the extraction with an additional 10-mL portion of chloroform. Evaporate the combined chloroform extracts on a steam bath to dryness. Agitate the dried residue with 2 mL of acetonitrile, and filter the mixture through a small sintered-glass funnel. Wash the crystals with an additional 2 mL of acetonitrile, and dry them with the aid of suction.
Acceptance criteria:  Meet the requirements
•  Procedure
Buffer:  Dissolve 1.6 g of anhydrous sodium acetate in 900 mL of water. Adjust with acetic acid to a pH of 4.0. Dilute with water to 1 L.
Mobile phase:  Methanol, acetonitrile, and Buffer (4:3:3)
Internal standard solution:  0.4 mg/mL of phenylephrine hydrochloride in Mobile phase
Standard stock solution:  0.2 mg/mL of USP Methylphenidate Hydrochloride RS in Mobile phase
Standard solution:  Mix 10.0 mL of the Standard stock solution with 5.0 mL of the Internal standard solution
Sample stock solution:  0.2 mg/mL of methylphenidate hydrochloride from finely powdered Tablets (NLT 20 Tablets) prepared as follows. Dissolve in Mobile phase using 70% of the final volume. Sonicate for 15 min, and cool to room temperature. Dilute with Mobile phase to volume. Pass a portion of this solution through a suitable membrane filter, discarding the first portion of the filtrate. Avoid the use of glass filters. Polypropylene filters are suitable for use.
Sample solution:  Mix 10.0 mL of the clear filtrate from the Sample stock solution with 5.0 mL of the Internal standard solution.
Chromatographic system 
Mode:  LC
Detector:  UV 210 nm
Column:  4.6-mm × 25-cm; packing L10
Flow rate:  1.5 mL/min
Injection size:  50 µL
System suitability 
Sample:  Standard solution
[Note—The relative retention times for phenylephrine hydrochloride and methylphenidate hydrochloride are 0.8 and 1.0, respectively. ]
Suitability requirements 
Resolution:  NLT 2.0 between the analyte and the internal standard peaks
Relative standard deviation:  NMT 2.0% from the peak response ratios of the analyte to the internal standard
Samples:  Standard solution and Sample solution
Calculate the percentage of methylphenidate hydrochloride (C14H19NO2·HCl ) in the portion of Tablets taken:
Result = (RU/RS) × (CS/CU) × 100
RU == peak response ratio of the analyte to the internal standard from the Sample solution
RS == peak response ratio of the analyte to the internal standard from the Standard solution
CS == concentration of USP Methylphenidate Hydrochloride RS in the Standard solution (mg/mL)
CU == nominal concentration of Methylphenidate Hydrochloride in the Sample solution (mg/mL)
Acceptance criteria:  93.0%–107.0%
•  Dissolution 711, Procedure for a Pooled Sample
Medium:  Water; 900 mL
Apparatus 1:  100 rpm
Time:  45 min
Analysis:  Determine the amount of methylphenidate hydrochloride (C14H19NO2·HCl) dissolved by using the procedure in the Assay, making any necessary volumetric adjustments.
Tolerances:  NLT 75% (Q) of the labeled amount of C14H19NO2·HCl is dissolved.
•  Uniformity of Dosage Units 905: Meet the requirements
•  Packaging and Storage: Preserve in tight containers.
•  USP Reference Standards 11
USP Methylphenidate Hydrochloride RS Click to View Structure
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Hariram Ramanathan, M.S.
Associate Scientific Liaison
(SM42010) Monographs - Small Molecules 4
711 Margareth R.C. Marques, Ph.D.
Senior Scientific Liaison
(GCDF2010) General Chapters - Dosage Forms
Reference Standards RS Technical Services
USP35–NF30 Page 3881
Pharmacopeial Forum: Volume No. 33(2) Page 246