A comparison of the Brazilian pharmacopeial methodologies for water determination in plant raw materials is presented for the following species: Calendula officinalis, Foeniculum vulgare, Maytenus ilicifolia e Passiflora alata. In addition, the validation of water determination by infrared drying was carried out for these species. The results obtained using the azeotropic distillation method (Brazilian Pharmacopoeia - "Determination of Water by Azeotropic Distillation") were significantly different (p<0.05) than those obtained using two different gravimetric methods (Brazilian Pharmacopoeia - "Determination of Water in Vegetable Drugs" and "Determination of loss on Drying"). However, no significant statistical difference was observed between the two gravimetric methodologies. After optimization of operating conditions, the results of water determination by infrared drying were not significantly different than those obtained using the loss on drying pharmaceutical method. Also, no statistically significant differences were observed for repeatability, intermediate precision and reproducibility of the method, demonstrating the accuracy and precision of the proposed methodology.
Vegetal drugs; determination of water; infrared drying
