(lox' a peen sux' i nate).
Butanedioic acid, compd. with 2-chloro-11-(4-methyl-1-piperazinyl)dibenz[b,f][1,4]oxazepine (1:1);
2-Chloro-11-(4-methyl-1-piperazinyl)dibenz[b,f][1,4] oxazepine succinate (1:1) [27833-64-3].
Loxapine Succinate contains NLT 98.5% and NMT 101.0% of C18H18ClN3O·C4H6O4, calculated on the dried basis.
• B. Ultraviolet Absorption 197U
Sample solution: 20 µg/mL in 0.01 N hydrochloric acid
Sample: 400 mg of Loxapine Succinate
Analysis: Dissolve in 80 mL of glacial acetic acid, and titrate with 0.1 N perchloric acid VS, determining the endpoint potentiometrically. Perform a blank determination, and make any necessary correction (see Titrimetry 541).
Calculate the percentage of C18H18ClN3O·C4H6O4 in the portion of Loxapine Succinate taken:
Result = [(V B) × N × F × 100]/W
Acceptance criteria: 98.5%101.0% on the dried basis
Buffer: 3.9 g/L of ammonium acetate in water. Adjust with 20% acetic acid in water or 6 N ammonium hydroxide to a pH of 7.3.
Mobile phase: Acetonitrile and Buffer (3:7)
Diluent: Acetonitrile and Buffer (7:3)
Standard solution: 10 µg/mL of USP Loxapine Succinate RS and 1.5 µg/mL each of USP Amoxapine RS and USP Loxapine Related Compound A RS in Diluent. [NoteAmoxapine has been included in the Standard solution for peak identification purposes only. ]
Sample solution: 1 mg/mL of Loxapine Succinate in Diluent
Detector: UV 254 nm
Column: 4.6-mm × 5-cm; 2.7-µm packing L1
Column temperature: 35
Flow rate: 1.5 mL/min
Injection size: 10 µL
Run time: 2 times the retention time of loxapine succinate
Sample: Standard solution
Resolution: NLT 2.0 between loxapine succinate and loxapine related compound A
Relative standard deviation: NMT 5.0%
Samples: Standard solution and Sample solution
Calculate the percentage of any individual impurity in the portion of Loxapine Succinate taken:
Result = (rU/rS) × (CS/CU) × (1/F) × 100
Individual impurities: See Impurity Table 1.
Total impurities: NMT 0.5%
• Loss on Drying 731: Dry a sample at 105 for 4 h: it loses NMT 0.5% of its weight.
• Packaging and Storage: Preserve in tight containers.
• USP Reference Standards 11
USP Loxapine Related Compound A RS
Auxiliary Information Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 3730Pharmacopeial Forum: Volume No. 36(4) Page 924