[Evaluation of film forming properties of a hydroxypropylmethylcellulose phthalate (HP 55) pseudolatex]

An hydroxypropylmethyl cellulose phthalate (HP55) pseudolatex was prepared by a nanoprecipitation method. This allows nanoparticles formation when a solution of the polymer in an organic solvent (phase S1 or organic phase) is introduced in a precipitant medium (phase S2 or aqueous phase) which consists of water containing surfactant. A modification of the solvent nature of phase S1 resulted in an improvement of the yield of the preparation. Then, the obtained pseudolatex was used to prepare films which were evaluated by mechanical tests and coating of tablets containing theophylline.