Evaluation of oral irritation of new formulations containing lysozyme, lactoferrin and poloxamer 407 as A carrier in vivo

The aim of this study was to evaluate the irritation effects on the oral mucosa of the hydrogel formulation (including lysozyme, lactoferrin and poloxamer 407 as carrier system), which has previously been shown to have antibacterial effects and biocompatibility in vitro, and to compare with 0.2% chlorhexidine gel in vivo conditions. In this study, the formulation which were prepared by combining, 1 mg/ml lysozyme, 0.5 mg/ml lactoferrin and 10% concentration of poloxamer 407 was used as experimental group. Sterile apyrogenic distilled water was used as negative control group and 0.2% chlorhexidine gel was used as reference product. The acute irritation effects of the experimental and control groups on the oral mucosa were evaluated macroscopically on the cheek mucosa of Syrian hamsters, and then the acute oral mucosa irritation scores were determined by histopathological examination. As a result of macroscopic evaluation, erythema or scar formation was not observed in any of the three groups. Histopathological examination revealed that the irritation level of lysozyme, lactoferrin and poloxamer 407 containing hydrogel was the same as that of sterile distilled water. When the irritation effects of chlorhexidine gel applications were compared with hydrogel containing lysozyme, lactoferrin and poloxamer 407, chlorhexidine gel was found to be the least irritating to the newly developed hydrogel. In this study, neither experimental group nor control groups showed severe mucosal irritation. However, it is believed that chronic oral mucosal irritation tests and delayed-type hypersensitivity tests w useful for understanding the longer-term effects of the hydrogel formulation containing lysozyme and lactoferrin.