Pilocarpine Hydrochloride
(pye'' loe kar' peen hye'' droe klor' ide).

C11H16N2O2·HCl 244.72
2(3H)-Furanone, 3-ethyldihydro-4-[(1-methyl-1H-imidazol-5-yl)methyl]-, monohydrochloride, (3S-cis)-;    
Pilocarpine monohydrochloride     [54-71-7].
DEFINITION
Pilocarpine Hydrochloride contains NLT 98.0% and NMT 102.0% of C11H16N2O2·HCl, calculated on the dried basis.
IDENTIFICATION
•  B. Identification Tests—General, Chloride 191: Meets the requirements
Sample solution:  50 mg/mL
ASSAY
•  Procedure
Buffer:  4.4 g/L of dibasic potassium phosphate in water. Adjust with phosphoric acid to a pH of 6.5 ± 0.1.
Mobile phase:  Acetonitrile, methanol, and Buffer (2:35:63)
Standard solution:  0.5 mg/mL of USP Pilocarpine Hydrochloride RS in water. [Note—Sonicate if necessary. ]
System suitability solution:  Transfer a known quantity of USP Pilocarpine Hydrochloride RS in a suitable volumetric flask, and add water, equivalent to 10% of the volume of the flask, to dissolve. [Note—Sonicate as needed. ] Add 0.1 N sodium hydroxide, equivalent to 10% of the volume of the flask, quench immediately with the same volume of 0.1 N hydrochloric acid, and mix. Dilute with water to volume. [Note—The initial concentration of USP Pilocarpine Hydrochloride RS is 0.5 mg/mL. Isopilocarpine is formed in the System suitability solution preparation. ]
Sample solution:  0.5 mg/mL of Pilocarpine Hydrochloride in water. [Note—Sonicate if necessary. ]
Chromatographic system 
Mode:  LC
Detector:  UV 215 nm
Column:  4.6-mm × 15-cm; 3-µm packing L11
Column temperature:  35
Flow rate:  1.0 mL/min
Injection size:  10 µL
System suitability 
Samples:  Standard solution and System suitability solution
Suitability requirements 
Resolution:  NLT 1.5 between isopilocarpine and pilocarpine, System suitability solution
Tailing factor:  NMT 2.0, Standard solution
Relative standard deviation:  NMT 2.0%, Standard solution
Analysis 
Samples:  Standard solution and Sample solution
Calculate the percentage of C11H16N2O2·HCl in the portion of Pilocarpine Hydrochloride taken:
Result = (rU/rS) × (CS/CU) × 100
rU== peak area from the Sample solution
rS== peak area from the Standard solution
CS== concentration of USP Pilocarpine Hydrochloride RS in the Standard solution (mg/mL)
CU== concentration of Pilocarpine Hydrochloride in the Sample solution (mg/mL)
Acceptance criteria:  98.0%–102.0% on the dried basis
IMPURITIES
Organic Impurities 
•  Procedure 1: Related Compounds
Mobile phase, Standard solution, System suitability solution, and Sample solution:  Proceed as directed in the Assay.
Sensitivity solution:  0.25 µg/mL of USP Pilocarpine Hydrochloride RS in water from the Standard solution
Chromatographic system 
Mode:  LC
Detector:  UV 215 nm
Column:  4.6-mm × 15-cm; 3-µm packing L11
Column temperature:  35
Flow rate:  1.0 mL/min
Run time:  NLT 5 times the retention time of the pilocarpine peak
Injection size:  10 µL
System suitability 
Samples:  Standard solution, System suitability solution, and Sensitivity solution
Suitability requirements 
Resolution:  NLT 1.5 between isopilocarpine and pilocarpine, System suitability solution
Signal-to-noise ratio:  NLT 10 for the pilocarpine peak, Sensitivity solution
Relative standard deviation:  NMT 2.0% for the pilocarpine peak, Standard solution
Analysis 
Samples:  Standard solution and Sample solution
Calculate the percentage of each impurity in the portion of Pilocarpine Hydrochloride taken:
Result = (rU/rS) × (CS/CU) × 100
rU== peak area of each individual impurity from the Sample solution
rS== peak area of pilocarpine from the Standard solution
CS== concentration of USP Pilocarpine Hydrochloride RS in the Standard solution (mg/mL)
CU== concentration of Pilocarpine Hydrochloride in the Sample solution (mg/mL)
Acceptance criteria 
Individual impurities:  See Impurity Table 1. [Note—Disregard any unspecified impurity peaks less than 0.05%. ]
Total impurities:  NMT 1.0%
Impurity Table 1
Name Relative
Retention
Time
Acceptance
Criteria,
NMT (%)
lsopilocarpinea 0.94 1.0
Pilocarpine 1.00
Pilocarpic acidb 1.15 0.5
Isopilocarpic acidc 1.19 0.1
Any unspecified impurity 0.1
a  (3R,4R)-3-Ethyl-4-[(1-methyl-1H-imidazol-5-yl)methyl]dihydrofuran-2(3H)-one.
b  (2S,3R)-2-Ethyl-4-hydroxy-3-[(1-methyl-1H-imidazol-5-yl)methyl]butanoic acid.
c  (2R,3R)-2-Ethyl-4-hydroxy-3-[(1-methyl-1H-imidazol-5-yl)methyl]butanoic acid.
•  Procedure 2: Other Alkaloids
Sample solution:  10 mg/mL in water
Analysis:  Divide the Sample solution into two portions. To one portion add a few drops of 6 N ammonium hydroxide, and to the other, add a few drops of potassium dichromate TS.
Acceptance criteria:  No turbidity is produced in either solution.
SPECIFIC TESTS
•  Optical Rotation, Specific Rotation 781S: +88.5 to +91.5
Sample solution:  20 mg/mL, in water
•  Loss on Drying 731: Dry a sample at 105 for 2 h: it loses NMT 3.0% of its weight.
•  Readily Carbonizable Substances Test 271
Sample solution:  50 mg/mL in sulfuric acid
Acceptance criteria:  The solution has no more color than Matching Fluid B.
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Preserve in tight, light-resistant containers. Store at room temperature.
•  USP Reference Standards 11
USP Pilocarpine 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 Feiwen Mao, M.S.
Senior Scientific Liaison
1-301-816-8320
(SM32010) Monographs - Small Molecules 3
Reference Standards RS Technical Services
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rstech@usp.org
USP35–NF30 Page 4322
Pharmacopeial Forum: Volume No. 35(6) Page 1473