Objective To optimize the preparation process of Bajitian Formula (复方巴戟天) nano-suspension and evaluate its pharmacological efficacy in prophylactic treatment for mice with memory-impaired Alzheimer’s disease after performance characterization. Methods Taking Bajitian Formula as the study subject, and based on single-factor analysis, the formulation process of Bajitian Formula nano-suspension was optimized via high-pressure homogenization with stabilizer dosage, homogenization pressure, and number of homogenization cycles as influencing factors, followed by performance characterization. The paddle method was employed to identify the optimal in vitro release medium, and the in vitro release behavior of polysaccharides in the Bajitian Formula nano-suspension was investigated. Pharmacodynamic experiments were performed to evaluate the preventive effect of the nano-suspension on memory impairment in Alzheimer’s disease model mice. Results The optimized formulation process for Bajitian Formula nano-suspension was determined as follows: the mass ratio of crude herbs to soybean lecithin was 1:0.6, high-pressure homogenization pressure was 40.0 MPa (400 bar), and homogenization cycles were 7. The particle size of the nanoparticle suspension was measured as (203.46 ± 2.67) nm, with a PDI of 0.200 ± 0.002. The optimal in vitro release medium was a 10 mg/mL SDS aqueous solution, achieving a cumulative total polysaccharide release rate of (72.10 ± 1.19)% after 24 h. After 30 d of oral administration of the optimized nanoparticle suspension, compared with the model group, the latency period of escape behavior was significantly shortened in both the positive control group and the medium-and high-dose groups of Bajitian Formula nano-suspension in the spatial navigation experiment (P < 0.05, 0.01). In the spatial exploration experiment, the number of target quadrant entries was significantly increased in the positive control group, decoction group, and low-, medium-, and high-dose groups of Bajitian Formula nano-suspension. The swimming distance to target quadrants was significantly increased in the positive control group and low-, medium-, and high-dose groups of Bajitian Formula nano-suspension (P < 0.05, 0.01). In the positive control group and low-, medium-, and high-dose groups of Bajitian Formula nano-suspension, the acetylcholine (ACh) content in the hippocampus and prefrontal cortex was significantly increased. In the positive control group and medium-and high-dose groups of Bajitian Formula nano-suspension, choline acetyltransferase (ChAT) activity in the hippocampus and prefrontal cortex was significantly elevated, while acetylcholinesterase (AChE) activity in these regions was significantly reduced (P < 0.05, 0.01). Conclusion The formulation optimization process of Bajitian Formula nano-suspension is rational and feasible, with preparation properties meeting nanoscale requirements, demonstrating uniform particle dispersion and good stability. Characterized by slow and sustained release, with excellent in vitro release behavior. It exhibits significant preventive effects against memory decline induced by Alzheimer’s disease, surpassing the efficacy of optimized decoction formulations. This study provides a beneficial reference for the modernization and technical upgrading of traditional dosage forms.

Bajitian Formula  /  Alzheimer’s disease  /  decoction powder  /  nano-suspension  /  preparation process  /  memory enhancement