EFECTO DE LA HUMEDAD RESIDUAL Y DE LA FUERZA DE COMPRESION SOBRE LA FORMACION DE MATRICES DE POLIVINILACETATO EN TABLETAS DE TEOFILINA DE LIBERACION CONTROLADA.

Abstract

The effect that exert the presence of humidity and the force of compression upon the in vitro rate of release of theophyllin from tablets which contain 90% of theophyllin, 9% of POVIAC and I % of magnesium stearate is studied. For this purpose were prepared tablets in a hydraulic press and using a tabletting machine, from granulates with different content of residual moisture and using different compression forces. It is concluded that both, the presence of a certain level of residual moisture in the granulates and the progressive heating of the dies and punches after a not very high number of compression, are factors that determine hat the rate of release can become independent from the appliance of compression forces higher than a certain value . Both factors favor the formation of a more complete polymeric matrix in the tablet. Another factor that can affect the rate of release is the presence in the tablet of occluded air; the more the higher is the applied compression force.