The intra-buccal polymeric bioadhesive systems that can stay adhered to the oral soft tissues for drug programmed release, with the preventive and/or therapeutic purpose has been employed for large clinical situations. A system based on hydroxypropyl methyl cellulose/Carbopol 934'/magnesium stearate (HPMC/Cp/StMg) was developed having the sodium fluoride as active principle. This kind of system was evaluated according to its resistance to the removal by means of physical test of tensile strength. Swine buccal mucosa extracted immediately after animals' sacrifice was employed as substrate for the physical trials, to obtain 16 test bodies. Artificial saliva with or without mucin was used to involve the substrate/bioadhesive system sets during the trials. Artificial salivas viscosity was determined by means of Brookfield viscometer, showing the artificial saliva with mucin 10.0 cP, and the artificial saliva without mucin 7.5 cP. The tensile strength assays showed the following averages: for the group "artificial saliva with mucin" - 12.89 Pa, and for the group "without mucin" - 12.35 Pa. Statistical analysis showed no significant difference between the assays for both artificial salivas, and it was possible to conclude that the variable mucin did not interfered with the bioadhesion process for the polymeric devices. The device was able to release fluoride in a safe, efficient and constant way up to 8 hours.

Los sistemas bioadhesivos poliméricos intra-bucales pueden permanecer adheridos a los tejidos blandos orales para una liberación programada de fármacos, con finalidad preventiva y/o propósito terapéutico han sido empleados en diversas situaciones clínicas. Un sistema basado en Hidroxipropilmetilcelulosa/Carbopol934Ô/ estearato de magnesio (HPMC/Cp/StMg) fue desarrollado con fluorato de sodio como principio activo. Este tipo de sistema fue evaluado de acuerdo a su resistencia a la eliminación física por medio de pruebas de resistencia a la tracción. Mucosas bucales de cerdos fueron tomadas inmediatamente después del sacrificio de los animales y se utilizaron como sustrato para las pruebas físicas, obteniendo 16 cuerpos de prueba. Saliva artificial con o sin mucina fue utilizada para participar como parte del sistema sustrato/bioadesivo durante los ensayos. La viscosidad de la saliva artificial, se determinó mediante un viscosímetro Brookfield, mostrando la saliva artificial con mucina 10,0 cP y saliva artificial sin mucina 7,5 cP. Las pruebas de resistencia a la tracción mostraron los siguientes promedios: para la "saliva artificial con mucina" - 12,89 Pa, y para el grupo "sin mucina" - 12,35 Pa. El análisis estadístico no mostró diferencias significativas entre las pruebas de saliva artificial, y es posible concluir que la variable de mucina no interfiere con el proceso de bioadhesión del dispositivo polimérico. El dispositivo fue capaz de liberar fluor de forma segura, eficiente y constante durante un máximo de hasta 8 horas.

A liberação transdérmica de muitos fármacos é dificultada pelas características de barreira do estrato córneo. Promotores químicos de absorção cutânea são capazes de interagir com os constituintes do estrato córneo, induzindo aumento temporário e reversível na permeabilidade da pele. O objetivo deste trabalho foi avaliar a influência de sistemas monoleína (monoleato de glicerol)/solventes na absorção percutânea de um fármaco lipofílico (a progesterona), através do estrato córneo de camundongos sem pelo, bem como o efeito da monoleína nas características estruturais do estrato córneo, por meio de microscopia eletrônica de varredura (SEM) e microscopia de varredura confocal a laser (CLSM). As alterações morfológicas observadas no estrato córneo de camundongos sem pelo sugerem efeito da monoleína na barreira da pele. E, ainda, o aumento no fluxo In vitro da progesterona, bem como na penetração in vivo do marcador fluorescente (fluoresceína), apontam a monoleína como potencial promotor de absorção cutânea. Os resultados obtidos mostraram que os sistemas monoleína/solventes provocaram alterações na estrutura do estrato córneo, que poderiam causar o aumento da permeação da progesterona através da pele de camundongos sem pelo, otimizando, deste modo, a liberação transdérmica deste fármaco.

Transdermal delivery of most drugs is precluded by the barrier characteristics of the stratum corneum (SC). Chemical penetration enhancers are capable of interacting with SC constituents, inducing a temporary reversible increase in the skin permeability. The aim of this work was to assess the influence of glycerol monooleate (GMO)/solvents systems on percutaneous absorption across hairless mouse SC of a lipophilic drug, progesterone (PG), as well as its effect on the SC structural characteristics, by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The morphological changes observed in the hairless mouse SC suggest a GMO effect on the skin barrier. In addition, the increase in the In vitro PG flux and in vivo penetration of a fluorescent label point towards GMO as a potential absorption enhancer. The results obtained showed that GMO/solvents systems provoked changes in the SC that could be causing increased permeation of PG across hairless mouse skin, optimising in this way the transdermal delivery of this drug.