Pharmacokinetics, pharmacodynamics and toxicity of Baicalin liposome on cerebral ischemia reperfusion injury rats via intranasal administration

Baicalin (BA) is a major active component from the traditional Chinese medicine, which has been widely used to treat brain diseases. Previously, the baicalin liposome (BA-LP) was prepared to improve its low bioavailability. However, the existence of the obstacles such as the blood-brian-barrier (BBB) still make it difficult to enter brain effectively. Meanwhile, many reports have shown that drugs can be transported into brain through intranasal administration without the BBB. Therefore, we aim to explore the effect of BA-LP on middle cerebral artery occlusion (MCAO) rats via i.n. administration. The results showed that BA and BA-LP had no obvious impact on mucosa after i.n. administration. And in pharmacokinetics study after i.n. administration, the value of t 1/2 and AUC 0-t in BA-LP group were significantly higher than that of the BA group (p < 0.05), indicating BA-LP could prolong the extension time of BA in vivo and further improve the bioavailability. In the brain biodistribution, the BA-LP group showed a higher BA concentration in brain tissues. Pharmacodynamics studies showed that BA-LP through i.n. administration could significantly improve the neurological deficits, cerebral infarction and brain pathological status in rats with MCAO surgery. Obviously, the BA-LP was more effective after nasal administration than intravenous administration, suggesting the nasal administration is more advantageous route in brain concentration enrichment. In conclusion, BA-LP could be safely used in i.n. administration, which can effectively improve brain targeting effect and thus protect the MCAO rats. Furthermore, successful use of the BA-LP via nasal delivery can provide a model for other drugs with neuroprotective effect and further promote the cure rate of brain diseases.