Osteogenic effect of locally applied Pentoxyfilline gel: in vitro and in vivo evaluations

The aim of this study was to formulate Pentoxyfylline drug (PTX) as a local bioadhesive Carbopol (Cbp) based gels for the aid of bone induction around an endosseus oral implant. The local delivery of the drug will probably avoid most of the problems associated with its systemic use including; disturbances in gastrointestinal tract and the central nervous system. Two concentrations of 1% and 3% Cbp containing 1% PTX were prepared. The gels were investigated for their physicochemical properties. Cbp based gels were found to be translucent with good homogeneity, uniform distribution of the drug and absence of any lumps. The pH of the gels was within neutrality, 7.1, which is considered to be acceptable to avoid the risk of any possible irritation in the oral cavity. The Cbp gels exhibited satisfactory bioadhesive properties and a pseudo-plastic rheological behavior. Cumulative drug released from the gels showed a controlled-release for more than 24 hours with the order of 3% >1% and the drug was released by diffusion mechanism from both gels. Statistical analysis revealed non-significant difference in drug content, rheological property and release rate of the stored gels for six months compared to the fresh ones. In vivo experimental results in rabbits have shown significant difference in bone depth induction of 3% and 1% Cbp gels with the formation of strong organized bone over the control group. Local administration of Pentoxifylline could be regarded as a valid approach in the management of osseointegration.