Novel inhaled salvianolic acid B (Sal B) showed safety and effectiveness in treating idiopathic pulmonary fibrosis (IPF), according to a study recently published in the Asian Journal of Pharmaceutical Sciences.
A formulation of Sal B and L-leucine (LL) constituted the dry powder inhaler (DPI) used in the study by Lu and colleagues. The delivery efficiency surpassed 70% in all tested concentrations, achieving a maximum fine particle fraction with 20% LL content. The product appeared to be stable after being stored in a brown dryer at room temperature for 35 days.
Read more about IPF therapies
In vitro studies using NIH-3T3 mouse embryonic cells compared the effects of nidanib and Sal B, revealing promising results in the different pathophysiological processes associated with IPF. For example, a concentration of 125 μg/mL Sal B-DPI produced a comparable inhibitory effect on collagen deposits to 0.5 μM nidanib.
Both compounds also significantly decreased the transforming growth factor β1 (TGF-β1)-induced migration of NIH-3T3 cells. Sal B-DPI further generated a decreased expression of fibrosis-related factors such as I collagen type α1, III collagen type α, intercellular adhesive molecule 1, fibronectin, inducible nitric oxide synthase, and arginase type 1 with a dose of 50 μg/mL.
Finally, although no important difference could be determined regarding interleukin 8 and lactate dehydrogenase concentrations in the bronchoalveolar lavage fluid between the control group and the Sal B-DPI group, the total protein concentration did differ at 8.08±0.76 mg/mL and 8.99±0.33 mg/mL, respectively.
Further in vivo experiments in rats reported an absolute bioavailability of Sal B-DPI of 59.67%±6.30%, exhibiting a significant increase when compared to that of the oral administration (19.15%±7.44%) as described in previous research.
“From the perspective of systemic absorption, the development of Sal B pulmonary drug delivery system is very promising,” the authors explained. “The therapeutic effect of drugs is usually directly related to the drug concentration of the target. The concentration of Sal B in lung tissue was still 2940.62±117.04 ng/g after 1 h of pulmonary administration, indicating that dry powder inhalers have certain advantages in the treatment of pulmonary diseases (such as IPF).”
Lu P, Li J, Liu C, et al. Salvianolic acid B dry powder inhaler for the treatment of idiopathic pulmonary fibrosis. Asian J Pharm Sci. Published online April 30, 2022. doi:10.1016/j.ajps.2022.04.004