Buspirone Hydrochloride
C21H31N5O2·HCl 421.96
8-Azaspiro[4,5]decane-7,9-dione, 8-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-, monohydrochloride;
N-[4-[4-(2-Pyrimidinyl)-1-piperazinyl]butyl]-1,1-cyclopentanediacetamide monohydrochloride
[33386-08-2; 36505-84-7].
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C21H31N5O2·HCl 421.96
8-Azaspiro[4,5]decane-7,9-dione, 8-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-, monohydrochloride;
N-[4-[4-(2-Pyrimidinyl)-1-piperazinyl]butyl]-1,1-cyclopentanediacetamide monohydrochloride
[33386-08-2; 36505-84-7].DEFINITION
Buspirone Hydrochloride contains NLT 97.5% and NMT 102.5% of C21H31N5O2·HCl, calculated on the as-is basis.
IDENTIFICATION
• B.
The relative retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.
• C. Identification Tests—General, Chloride 
191
:
Meets the requirements
191:
Meets the requirements
Sample solution:
10 mg/mL in water
ASSAY
• Procedure
Buffer:
1.36 g/L of monobasic potassium phosphate in water. Adjust the solution with 10% sodium hydroxide (w/v) to a pH of 7.5, and filter.
Mobile phase:
Acetonitrile and Buffer (2:3)
Internal standard stock solution:
2.5 mg/mL of propylparaben in methanol
Internal standard solution:
0.125 mg/mL of propylparaben from the Internal standard stock solution in water
Standard stock solution:
Dissolve 50 mg of USP Buspirone Hydrochloride RS in 25 mL of 1 N hydrochloric acid in a 100-mL volumetric flask, and dilute with water to volume.
Standard solution:
To 10.0 mL of Standard stock solution in a 50.0-mL volumetric flask add 10.0 mL of Internal standard solution, and dilute with water to volume.
Sample stock solution:
Dissolve 50 mg of Buspirone Hydrochloride in 25 mL of 1 N hydrochloric acid in a 100-mL volumetric flask, and dilute with water to volume.
Sample solution:
0.1 mg/mL of Buspirone Hydrochloride from the Sample stock solution and 0.025 mg/mL of propylparaben from the Internal standard solution in water
Chromatographic system
Mode:
LC
Detector:
UV 254 nm
Column:
3.9-mm × 30-cm; packing L1
Flow rate:
2 mL/min
Injection size:
25 µL
System suitability
Sample:
Standard solution
[Note—The relative retention times for propylparaben and buspirone hydrochloride are about 0.55 and 1.0, respectively. ]
Suitability requirements
Resolution:
NLT 4 between buspirone hydrochloride and the internal standard
Relative standard deviation:
NMT 2.0%
Analysis
Samples:
Standard solution and Sample solution
Calculate the percentage of C21H31N5O2·HCl in the portion of Buspirone Hydrochloride taken:
Result = (RU/RS) × (CS/CU) × 100
| RU | = | = peak response ratio of buspirone hydrochloride to propylparaben from the Sample solution |
| RS | = | = peak response ratio of buspirone hydrochloride to propylparaben from the Standard solution |
| CS | = | = concentration of USP Buspirone Hydrochloride RS in the Standard solution (mg/mL) |
| CU | = | = concentration of Buspirone Hydrochloride in the Sample solution (mg/mL) |
Acceptance criteria:
97.5%–102.5% on the as-is basis
IMPURITIES
SPECIFIC TESTS
• Water Determination, Method I 921:
NMT 0.5%
921:
NMT 0.5%
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in tight, light-resistant containers, at controlled room temperature.
• USP Reference Standards 11
11
USP Buspirone Hydrochloride RS 
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Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Ravi Ravichandran, Ph.D.
Principal Scientific Liaison 1-301-816-8330 |
(SM42010) Monographs - Small Molecules 4 |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
USP35–NF30 Page 2408
Pharmacopeial Forum: Volume No. 36(1) Page 74