Estudo da dissolução in vitro de extratos fitoterápicos.

Abstract

The break-stone (Phyllantus Niruni l.) is an herb widely used by traditional medicine with established pharmacological activity. The active principia in the extract are chemical compounds like steroids, alkaloids and phenolic compounds, such as tannins and flavonoids, among others. In this work the in vitro dissolution of tannins from granules of break-stone, coated in a conventional spouted bed by a film of gastro resistant polymer, Eudragit base was studied. Gastro-resistant coating is a technique used in the preparation of pharmaceutical forms in order to resist gastric juice action, but quickly disintegrate and absorb in intestinal juice. The primary goal of this work was to assess the effect of process variables: polymer suspension flow rate and air temperature, on the efficiency of the dissolution. The in vitro dissolution tests were conducted in two stages: acidic and alkaline, representing gastric and enteric media respectively. In all the studied conditions a partial gastro-resistance of the coating film was observed because some phenols were dissolved during the acid stage. The best operating conditions for the process of coating in spouted bed were identified in order to obtain gastro-resistant liberation of the pharmaceutical active components in the granules.