Preparation of resveratrol-DPPC liposomal dry powder inhalations and its antibacterial activities / 中草药

ABSTRACT

Objective To prepare the resveratrol-DPPC liposomal dry powder inhalations (RDLDPIs), and solve the problem of lower bioavailability of resveratrol after oral administration. Methods The RDLDPIs were prepared by film-dispersion and freeze drying. The formulation was optimized by orthogonal design. The particle size, entrapment efficiency, electric potential, in vitro release, and lung deposition were characterized. The broth microdilution method was used to evaluate the antibacterial activity and determine the minimal inhibitory concentration (MIC) in vitro. Results The optimized ratio of DPPC/cholesterol, resveratrol/DPPC, and mannitol/DPPC was 31, 13, and 21 in the prescription of RDLDPIs, respectively; And hydration time was 15 min. The entrapment efficiency of RDLDPIs was (69.8 ± 1.6)%, the drug loading was (2.4 ± 0.9)%, the particle size was (191.5 ± 4.5) nm, and the zeta potential was (12.4 ± 1.5) mV. The aerodynamic particle size of the powder was (3.2 ± 0.2) μm and the in vitro pulmonary deposition ratio was 28.1% in vitro. The antibacterial activity against Staphylococcus aureus, Acinetobacter baumannii, Streptococcus pneumoniae, and Pseudomonas aeruginosa was evaluated in vitro. The crude drug group had no antibacterial activity in four species of bacteria, while RDLDPIs had antibacterial activity of Staphylococcus aureus and Acinetobacter baumannii, and MIC was 4 mg/mL and 2 mg/mL, respectively. Conclusion The prepared RDLDPIs have small size and uniform distribution with good stability and high lung deposition rate and in vitro antibacterial activity against Staphylococcus aureus and Acinetobacter baumannii, which is expected to be an substitute for traditional antibiotics for the treatment of bacterial pneumonia.