The aim of the present work is to characterize the vegetal raw material of the Calycophyllum spruceanum (Benth.) Hook. f. ex K. Schum., Rubiaceae, known as "mulateiro", and to evaluate the influence of extractive parameters for attainment of standardized aqueous extractive solutions. The physical-chemical characterization of the samples was performed using pharmacopoeic and not pharmacopoeic methodologies. A 23 factorial design was used to evaluate the influence of extraction techniques (infusion/decoction), drug: solvent ratio (2.5 and 7.5%), and extraction time (5 and 15 min) on the total tannin content of aqueous extractive solutions from C. spruceanum. The extractive solution that showed higher total tannin and dry residue content had their physical-chemical characteristics determined. The results suggest that an aqueous extractive solution from rinds of C. spruceanum barks with higher tanning yield (9.9 g%), must be standardized using decoction as extraction methodology, with 2.5% of vegetal drug for an extraction time of 15 min. The results of the physical-chemical characterization suggest that environmental factors modify the properties of this species and, therefore, they can influence the quality and security of a product derived from this medicinal plant.