The buccal mucosa, which contains non-keratinized epithelial cells lining the inner cheeks of the mouth, is a site for local and systemic delivery of medication. This region is highly vascularized and relatively immobile. Buccal delivery allows for the active ingredients to exert rapid onset of action, bypassing liver first pass-metabolism, and avoiding pH fluctuations and degradation within the gastrointestinal tract. Due to the small absorptive surface of the buccal mucosa, mucoadhesive polymers have been developed to prolong mucoadhesion and increase residence time (time at the site of action). Mucoadhesive polymers are often used to deliver medication for the treatment of local diseases and conditions of the oral mucosa such as mucositis (inflammation of the mucous membrane), ulcers, infections, and candidiasis. The prolonged intimate contact between the delivery system and the tissue require these polymers to be non-irritating and non-toxic in order to minimize adverse effects and patient discomfort. The purpose of this study is to evaluate the safety and toxicological profile of MucoLox, in comparison to Triton X-100 (positive control) and distilled water (negative control), using a 3-dimensional (3D) model of the human oral mucosa. MucoLox is a proprietary polymer gel that acts as a delivery system to improve mucoadhesion and prolong retention of medications at application sites within the oral mucosa. Triton X-100 is a nonionic surfactant, not approved for oral use, used in this study as a positive control.
Mucoadhesive polymers are delivery systems designed to overcome low mucosal retention associated with buccal delivery of medication. Due to the prolonged contact between the delivery system and mucosal tissues, irritancy and toxicity potentials of these polymers should be considered. This study was designed to compare the safety and toxicological profile of MucoLox, a mucoadhesive polymer gel, to that of Triton™ X-100 (positive control) and distilled water (negative control), using a three-dimensional (3D) model of the human oral mucosa. Results show that MucoLox is potentially as safe as distilled water following 4.5 hr of exposure (98% mean cell viability). MucoLox is less toxic than Triton X-100 as the amount of time required to reduce cell viability to 50% was 6 times longer for MucoLox than that of Triton.
Figure 1. Illustration of the EpiOral tissue model.
Figure 2. Mean percent cell viability of MucoLox and Triton X-100.
MucoLox improves mucoadhesion and prolongs retention of medications at application sites within the oral mucosa. The evaluation of the safety and toxicological profile of MucoLox is very important taking into account the prolonged intimate contact between the delivery system and the oral mucosa. An ideal mucoadhesive should facilitate healing without causing damage and irritation to surrounding tissues. MucoLox can bind to tissues 6 times longer than Triton X-100 (before 50% cell viability) which indicates that MucoLox is not toxic when compared to Triton X-100. In addition, cell viability at 98% after 4.5 hr with MucoLox exposure suggests that MucoLox is potentially as safe as distilled water. MucoLox may then be used in pharmaceutical compounding as a safe option in the treatment of diseases and conditions of the oral mucosa such as oral mucositis, candidiasis and mouth ulcers.