Tetracycline and/or hydrocortisone incorporation and release by bioactive glasses compounds

The delivery of the tetracycline and hydrocortisone drugs that have been incorporated into bioactive glasses was studied in this work. The potentiality of these systems in direct pulp capping is also discussed. A bioactive glass with a composition of (SiO2)(0.80)(P2O5)(0.04)(CaO)(0.16), was prepared by sol-gel. Sols were prepared with the addition of approximately 2 wt% of tetracycline or hydrocortisone separately for the delivery studies. A third set of samples of bioglass sols containing 2 wt% of each drug were prepared with the same purpose. The amounts of drugs delivered were monitored by ultraviolet spectrophotometry in the tetracycline and hydrocortisone wavelengths. The drug release behavior was strongly dependent on the system. The glass-tetracycline samples showed a rapid drug release kinetics, while glass-hydrocortisone samples show much slow release profiles. The different drug release behaviors have been explained by faster gel formation reaction between hydrocortisone and TEOS due to a stronger interaction between these reagents. On the samples with both drugs, the release was simultaneous and for each drug, the amounts delivered followed a profile similar to the samples with only this specific drug. (C) 2009 Elsevier B.V. All rights reserved.