Gelatin as a Chlorhexidine Digluconate Immobilizing Agent

Abstract

Periodontal disease is an infectious-inflammatory disease that affects the supporting tissues of the teeth.This process results in inflammation within the supporting tissues of the teeth, progressive loss of attachment and bone loss and is characterized by periodontal pocket formation and/or recession of the gingiva. Chlorhexidine is a chemical agent widely used in dentistry, in the fight against periodontal disease and a wide range of infections, mainly thanks to its potent antimicrobial activity. Despite the excellent properties, chlorhexidine is an extremely hydrophilic drug, usually obtained in the aqueous solution form, making it hard to be incorporated into polymer controlled release systems. Successive lyophilization processes were inefficient for water removal. This work aimed to use gelatin as a chlorhexidine immobilizing agent. This procedure allowed the obtaining of a powder, which will be used as a drug controlled release film. The incorporation of chlorhexidine in a hydrophilic polymer matrix is already a well-established procedure. However, aiming the future preparation of a slower release device, we proposed the incorporation of the drug into a hydrophobic polymer matrix. To achieve this next purpose, it was necessary the immobilization of chlorhexidine in gelatin, which is reported here. More specifically, three gelatin and chlorhexidine systems were prepared. The characterizations were performed to understand the effect of different amounts of chlorhexidine on the obtaining of the system as a powder by lyophilization. Besides that, the capability of these systems to generate a microbiological response against two of the more significant microorganisms involved in the development of periodontal disease, Aggregatibacter actinomycetemcomitans (A.a), and Porphyromonas gingivalis (P.g), were evaluated as well. The results showed that the incorporation was carried out successfully. Also, the aspect of the obtained powder has a direct relation to the concentration of chlorhexidine. Regarding the microbiological test, the results show that all systems are capable of producing an efficient inhibition halo.