Estudo da dissolução in vitro de grânulos do extrato de quebra-pedra (Phyllanthus Niruni L.) recobertos em leito de jorro.

Abstract

The objective of this work was to study the in vitro dissolution process of breaker stone (Phyllanthus niruri L.) phitotherapic extract coated with a polymeric suspension of Eudragit L-30D-55® by spouted bed. Methacrylic acid-methylmetacrylate copolymer, also known as Eudragit, have been used as a pH sensitive coating material to protect drug substances prior to delivery to the human intestines. Gastricresistant coating is a technique used in the pharmaceutical industry as coating of solid dosage forms. Granules remained intact in acid during the dissolution in the acid stage, without changing the color and structure. As soon as the pH of the dissolution environment was changed (buffer stage), the granules disintegrated completely. The operational conditions studied in this work were coating suspension flow rate and drying air temperature over active ingredients efficiency: flavonoids content and total phenol. The dissolutions studies of the coated granules were performed in a dissolution test in a shaker (incubater chamber) at 100 rpm rotational speed and 37oC as alternative form at conventional dissolutor. The experimental runs were carried out in two stages: acid stage indicating the gastric medium and buffer stage meaning enteric medium. The release profiles indicated gastric-resistant with regard to flavonoids content and partial release total phenol content. The breaker stone granules were prepared by wet granulation technology using breaker stone dry extract and polivinilpirrolidone K-30 as a binder. The operational variables to wet granulation process were ethanol volume and granulation time. The effect of variables was analyzed about granules mechanic resistance. The granules were obtained by sieving aggitation. The mechanic resistance tests were perforned in conventional spouted bed. The results according to granulation process pointed out that increasing ethanol volume producing granules grater resistant. Nevertheless, the statistical analysis pointed out in both dissolution and granulation tests there is a necessity to enlarge of experimental design to axial points, in order to evaluate of an accurate form of the effect of independent process variable over response variables.