This work reports a bioavailability study between two oral dosage forms containing 125.2 mg active phloroglucinol. Twelve healthy volunteers subjects received a sublingual administration of both dosage forms, a flash liberation tablet and a freeze-dried reference tablet (lyoc), according to a randomized and cross-over design. An accurate, sensitive and specific high performance liquid chromatographic method was developed for the determination of free phloroglucinol as well as its conjugated metabolites, that allowed as to clarify phloroglucinol pharmacokinetic behaviour in man, specially its important metabolisation, its poor systemic bioavailability after oral administration and its total urinary elimination mainly under metabolized form. Total plasmatic phloroglucinol pharmacokinetic profiles led to pertinent parameters needed for statistical bioequivalence study, i.e. T1/2 alpha, T1/2 beta, AUC, Tmax, Cmax and MRT. The mean comparative values of these parameters showed the equivalent performances of both oral dosage forms studied and the statistical tests performed (ANOVA, Westlake and two one-sided t test) concluded to their bioequivalence.