Treatment with
antibiotics within the
periodontal pocket against
bacterial infections represents a useful and adjunctive tool to conventional
therapy for healing and teeth preservation. With this function in view, an implantable,
tetracycline delivery device for the treatment of
periodontal disease was developed. The aim of this study was to develop biodegradable,
tetracycline-loaded microparticles made of two
polymers: PLGA and
zein which were compressed into monolithic devices. In this
polymer delivery system, the encapsulation efficiency, release characteristics,
drug-
polymer interaction, and antibacterial activity of loaded
drug were investigated. The interaction of
tetracycline with the corn
protein zein was studied by nuclear magnetic resonance (NMR), Fourier transform infrared, and X-ray diffraction. The hydrophobic interaction of
tetracycline with
zein in the formulations was deduced from the NMR studies, whereas X-ray diffraction studies showed a new crystalline state of the
drug in the presence of the
protein.
Zein was not denatured by preparation of inserts. Sustained release of
tetracycline was obtained, and the proportion of
zein in the inserts had a great impact on the drug release. Finally, an effective
tetracycline release from inserts against Staphylococcus aureus was achieved over 30 days. In conclusion, the PLGA:
zein delivery system described in this study was found to be effective in controlled delivery of
tetracycline, and hence may be suitable for intra-pocket delivery of
antimicrobial agents in the treatment of
periodontitis.