Influence of particle size and hidrofobic coating on the release profile of gastrorrentive systems

GARCIA C; ARCE S; ARAGON L; ORTEGA C; SAIDMAN E; GOMEZ R

CORDOBA

Congreso; 3° REUNION INTERNACIONAL DE CIENCIAS FARMACEUTICAS 2014; 2014

Facultad de Ciencias Quimicas Universidad Nacional de Còrdoba

A modified release system with long residence time in the stomach, called gastrorretentive (floating tablets or pellets), has particular importance for drugs with local activity in the stomach, absorption window in the stomach or upper portions of the small intestine, instability to intestinal level or lowsolubility at high pH values.The aim of this work was to study the influence of the size of the granules of gastrorretentive tablets in the release profile of the active ingredient. Moreover, show the retarding effect of pH independent anionic polymer coatings in the release of active ingredient from modified release pellets.The following flow properties were evaluated for the different size of particles for the granules through sieve #10, #20 and #30: angle of repose, Carr & Hausner Index. The tablets were prepared by wet granulation and then compressed; uniformit y of weight, hardness, friability, drug content and in vitrobuoyancy were evaluated. The dissolution studies showed a modified release system after 24 hours for all formulations. The tablets exhibited a gelatinous film on the surface, and a central dry region near to 20 hours.The three coated pellets lots were evaluated for angle of repose, Carr & Hausner Index and drug content.All coated pellets and granules showed adequate rheological properties. The physical and chemical characteristics for all tablets were optimum.It was observed that for the smallest particle size, 10 mg is released from the swellable matrix after 3 hours, which corresponds to the desirable minimum effective concentration for optimal bioavailability.Better sustained drug release was observed at more layers of coated pellets, verifying the retarding effect of these coating