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JAVIER ARAGÓN FERNÁNDEZ Y COLS. AN. R. ACAD. NAC. FARM.

comprobar que la cefalexina es liberada mediante un fenómeno de
difusión de tipo Fickian a través de los poros o canales formados en
el sistema de liberación compuesto. Además, el fenómeno de relaja-
ción de las cadenas poliméricas no presenta una fuerte contribución
a la liberación de cefalexina, pero su inclusión en la ecuación per-
mite obtener un adecuado ajuste matemático.

Palabras clave: Biomateriales; Sistema de liberación; In vitro;
Difusión Fickian.

ABSTRACT

Kinetics of cefalexiane release form biomaterials formed
by HAP-200/POVIAC/CaCO3

The main objective of this work is to study the kinetics of
cefalexine release from a biomaterial compound developed recently,
to show that it can be used as a controlled release system, for
extended periods of time. Besides, different mathematical models
were adjusted to the release profiles obtained in each formulation,
with the purpose of determine the mechanism by which occurs the
release of cefalexine from a composite release system. It was shown
that the model proposed by Peppas and Sahlin was that the best fit
presented, because, takes into account the phenomenon of Fickian
diffusion and the phenomena of relaxation for polymeric chains. In
all cases the effect burst was discarded, for what can affirm that
almost all the medicine is occluded inside the formulations and not
on the surface of these. It could be that the cefalexine is released
through a phenomenon of Fickian diffusion through the pores or
channels formed in the compound delivery system. Moreover, the
phenomenon of relaxation for polymeric chains does not show a
strong contribution to the release of cefalexine, but its inclusion in
the equation, is necessary to obtain an appropriate mathematical
adjustment.

Key Words: Biomaterials; Release system; In vitro; Fickian
diffusion.

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