Characterization and in vitro release studies of tetracycline and rolitetracycline imobilized on anionic collagen membranes

Gilberto Goissis,Maria Helena De Sousa

doi:10.1590/s1516-14392009000100008

Gilberto Goissis, Maria Helena De Sousa

Open Access

https://doi.org/10.1590/s1516-14392009000100008

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Journal: Materials Research	Publication Date: Mar 1, 2009
Citations: 11	License type: cc-by

Affiliation: Universidade Federal de Goiás

Abstract

This work reports the covalent immobilization of tetracycline and rolitetracycline over anionic collagen membranes and the drug release studies as an effort to develop a two stage drug release based on diffusion (fast release) and on the rate of membrane biodegradation (slow release). Independent from casting conditions antibiotics incorporated by dispersion were released in the range from 80 to 100% within 7 hours in concentrations significantly higher than those described for the prevention of bacterial growth. Antibiotic release within this period was predominantly diffusion controlled. Covalent immobilization by a modified azide procedure occurred with preservation of collagen structure independently from pH of casting and reaction conditions. Its expected that anionic collagen membranes with dispersed and covalently bound rolitetracycline or tetracycline, in association with conventional therapy, may significantly reduce membrane induced infections observed post-implantation, one of the major problem associated with periodontal ligaments reconstruction by the Guided Tissue Regeneration procedure.

Highlights

Sustained drug release technology[1] is being applied from protein hormones such as insulin for the treatment of diabetes[2] to antibiotics for the prevention or minimization of bacterial infection[3,4,5]
The maintenance of collagen triple helix secondary structure was confirmed by thermal stability determined as Ts since independently the antibiotic immobilization procedure all anionic collagen membranes (ACM) were characterized by thermal transitions, which is absent in denatured collagen materials (Table 1) in the temperature range studied
Antibiotics release from ACM for releases from 60 to 70% were analyzed by means of the Higuchi equation Mt = Ktn 33 and independent from the antibiotic or membrane casting conditions showed values of n close to 0.50 (Figure 1b, Table 2). These results suggest that most of the antibiotics are released from ACM predominantly by diffusion with high release coefficient

Summary

Introduction

Sustained drug release technology[1] is being applied from protein hormones such as insulin for the treatment of diabetes[2] to antibiotics for the prevention or minimization of bacterial infection[3,4,5]. Advantages of this technology are associated with reduction in side effects, decreased systemic toxicity and higher efficiency due to high drug concentrations at the site of damage[6,7].

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