Desenvolvimento e avaliação de formas farmacêuticas sólidas contendo didanosina

A Sindrome da Imunodeficiencia adquirida (AIDS) e uma doenca de amplo espectro de manifestacoes, sendo razao de preocupacao para qualquer autoridade sanitaria. A terapeutica da AIDS e complexa sendo utilizados varios medicamentos, diversas vezes ao dia. Deste modo, objetivou-se o desenvolvimento de formas farmaceuticas solidas como comprimidos tamponados mastigaveis (CTM), comprimidos com revestimento gastro-resistentes (CRGR) e pellets (PEL) para a veiculacao de didanosina (ddl). Seis especialidades farmaceuticas na forma de CTM forma estudadas quanto ao perfil de dissolucao, pH do meio e capacidade neutralizante acida (CNA). Formulacoes teste de CTM foram propostas visando obter CNAs e perfis de dissolucao adequados. Tambem foram testadas formulacoes de comprimidos e de pellets para posterior revestimento com filme gastro-resistente derivado do acido metacrilico. Os ensaios de dissolucao das amostras de CTM revelaram diferencas nas caracteristicas de liberacao do farmaco. Tambem foram observadas diferencas relacionadas a CNA. As formulacoes de CTM propostas apresentaram, na maioria dos casos, adequados perfis de dissolucao e CNA. As formulacoes CRGR que receberam revestimento gastro-resistente apresentaram perfis de dissolucao de ddl adequados, entretanto os comprimidos testados intumesceram em meio acido, indicando descontinuidade do filme polimerico sobre os comprimidos. Testes para a producao de pellets veiculando ddl mostraram-se adequados quanto a morfologia e dissolucao do farmaco, o mesmo sendo observado apos o revestimento com filme gastro-resistente The Acquired Immune Deficiency Syndrome (AIDS) is a disease that manifests itself in a myriad of ways. Because of this, the condition has been subject of concern to all sanitary authorities. The treatment of AIDS is complex and many types of medicine are used, many times a day. The objective of the present study was to develop solid pharmaceutical dosage forms such as buffered chewable tablets (CTM), gastro-resistant coating tablets (CRGR) and pellets (PEL) for the loading of didanosine (ddl). Six pharmaceutical specialties in the form of CTM were studied so as to identify the profile of the dissolution, the pH of the environment, and the neutralizing acid capacity (CNA). The use of CTM tests formulations was proposed with the objective of obtaining adequate CNA and dissolution profiles. Different compositions of tablets and pellets were tested for a later addition of gastro-resistant film derived from the methacrylic acid. The experiments on the dissolution of the sample of CTM showed differences in the characteristic of the release of the substance. Differences related to the CNA were also observed. The formulations of the CTM proposed showed to have, in the most number of the cases, both adequate dissolution behavior and CNA. The formulations of the CRGR that had received the gastro-resistant coating showed adequate profile of ddl dissolution; the tested tablets, however, swelled in the acid environment, therefore indicating a lack of continuity of the polymeric film over the tablets. The tests for the production of pellets showed adequate results as to its morphology and dissolution of ddl. The same was observed after coating the pellets with gastro-resistant film.