Research Article

Development and Validation of Stability-Indicating GC-FID Method for the Quantitation of Memantine Hydrochloride and Its Nonchromophoric Impurities in Bulk and Pharmaceutical Dosages

Table 2

Forced degradation results.

Stress condition% Assay of memantine% of degradantObservation and mass balancePeak purity by GC-MS

Undegraded98.8
Acid hydrolysis
(Conc. HCl, 36 h refluxed)
100.6NilNo any known and unknown degradation product formed (Mass balance: 100.6%)Mass spectrum similar to the mass spectrum of reference standard
Base hydrolysis
(5 M NaOH, 36 h refluxed)
101.1NilNo any known and unknown degradation product formed (Mass balance: 101.1%)Mass spectrum similar to the mass spectrum of reference standard
Oxidation
(30% H2O2, 24 h at RT)
76.624.024.0% of unknown minor degradation products formed (Mass balance: 100.6%)Mass spectrum similar to the mass spectrum of reference standard
Thermal
(60°C, 8 days)
99.2NilNo any known and unknown degradation product formed (Mass balance: 99.2%)Mass spectrum similar to the mass spectrum of reference standard
Photolytic as per ICH99.2NilNo any known and unknown degradation product formed (Mass balance: 99.2%)Mass spectrum similar to the mass spectrum of reference standard

Mass balance = % assay + % sum of all impurities + % sum of all degradants.