Assay of mixtures of chlorpheniramine maleate, pyrilamine meleate and phenylpropanolamine hydrochloride in cold-allergy tablets by difference spectrophotometry

✍ Scribed by Henry S.I. Tan; Geraldine C. Salvador

• Book ID: 104100392
• Publisher: Elsevier Science
• Year: 1986
• Tongue: English
• Weight: 448 KB
• Volume: 188
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/s0003-2670(00)86056-0

✦ Synopsis

Mixtures ofchlorpheniramine maleate (CPM) and phenylpropanolamine hydrochloride (PPA), with and without pyrilamine maleate (PRM), are assayed by U.V. difference spectrophotometry without prior separation. The spectra for CPM and PRM in solutions at pH 1 and pH 6 show differences whereas the spectra for PPA remain the same at pH 1 and 6. For PPA, quantitation is based on the spectral change on oxidation to benzaldehyde with metaperiodate; this oxidation doesnot affect CPM and PRM. Calibration plots are linear for 6.7-99.6 rg ml-' CPM (r = 0.9992), 12.7-50.6 pg ml-' PRM (r = 0.9997) and 25-115.3 kg ml-' PPA (r = 0.9980) in the presence of one another. Average recoveries (* RSD) from simulated PPA/CPM tablets were: PPA, 98.4 + 0.4% (without PRM, n = 3), 99.8 * 0.4% (with PRM, R = 5); CPM, 99.3 + 0.6% (without PRM, n = 3), 99.2 r 0.4% (with PRM, n = 5); and PRM, 99.5 * 0.2% (in PPA/CPM/PRM tablets, n = 5).

The method was successfully applied to commercial cold-allergy tablets containing these compounds.