Preparation and Quality Evaluation of Salvianolic Acids and Tanshinones Dry Powder Inhalation

Salvianolic acids and tanshinones both exhibit efficacy in treating idiopathic pulmonary fibrosis (IPF), but their formulation limits their clinical use. This study aimed to prepare the salvianolic acids and tanshinones dry powder for inhalation (SPI) to achieve pulmonary delivery for the treatment of IPF. The variable quantities of salvianolic acids and tanshinones composite powder were optimized using the central composite design-response surface method. Different carriers with various drug-carrier ratios were optimized to prepare SPI. The final optimized formulation of SPI was as follows: InhaLac 230® was selected as the carrier with drug:carrier = 1:6, and the milled lactose InhaLac 400® was added at 5%. The developed SPI characterized with an angle of repose 52.46 ± 1.04°, Carr's index of 34.00 ± 0.50% and showed high lung deposition in vitro, indicating the potential of pulmonary delivery for the treatment of IPF.