phenazopyridine hydrochloride2,6-Diamino-3-(phenylazo)pyridine monohydrochloride2,6-Diamino-3-phenylazopyridine hydrochloride3-(Phenylazo)-2,6-pyridinediamine hydrochloride3-Phenylazo-2,6-diaminopyridine hydrochloridePhenazopyridine HClPhenazopyridinium chloridephenazopyridine monohydrochloride