Caracterización del alcohol polivinílico usado en recubrimientos de base acuosa Characterization of polyvinyl alcohol apply in aqueous film coatings

this study explores the possibility to use polyvinyl alcohol (PVA) like a film forming agent in tablet coating. PVA was used in mixture with hydroxipropylmethyl cellulose (HPMC), ethyl cellulose (Aquacoat ECD®), polymethacrylate (Eudra- git® NE-30D) and pigments dispersion (Cotolene). In the experiment placebo tablets were coated with four formulations PVA, PVA-HPMC, PVA-Eudragit and PVA-Cotolene. All the film coatings showed feasibility to use PVA alone and in combination with other film forming agents. The films protect appropriately the tablets, mechanical strength depends on the degree of polymers interpenetration, it was proposed that the disintegration time of the film is controlled by lesser soluble polymer and finally, two mechanisms were proposed during the drying of the film. Palabras clave: recubrimiento de pelicula, alcohol polivinilico, etil- celulosa, hidroxipropilmetilcelulosa y Eudragit