Study on in Vitro Release and Nasal Mucosal Toxicity of Ditong Biyan Spray Gel

OBJECTIVE To study the release characteristics in vitro and nasal mucosal toxicity of Ditong Biyan Spray Gel. METHODS The cumulative dissolution rate and release rate of Ditong Biyan Spray Gel were determined by non-membrane dissolution method in vitro release test. And then the release behavior of baicalin and ephedrine hydrochloride were fitted with mathematical model. The macro-irritation and the nasal mucosal toxicity of Ditong Biyan Spray Gel were conducted by sneezing experiment and HE staining method. RESULTS There was a strong linear relationship between the cumulative dissolution rate and the cumulative release rate in the dissolution curve. Furthermore, the release of baicalin and ephedrine hydrochloride in vitro conforms to the first-order kinetic equation with sustained release characteristics. This preparation was irritating to the nasal cavity of rats, but it could recover after discontinuation of drug. No redness, congestion and other phenomena in trachea, bronchus and lungs. HE staining showed that this preparation had slight damage to the nasal mucosa of rats. After 7 days of withdrawal, there were slight vacuolar degeneration and necrosis of glandular epithelial cells in the propria mucosa of positive group, and the other groups could recover to normal. CONCLUSION Ditong Biyan Spray Gel is a sustained-release preparation combined with dissolution and diffusion. It is a safe preparation with low toxicity to nasal mucosa, and it can recovery after discontinuation.