Kb ba100

The target COLI dose delivered was 0.35 mg kg⁻¹ (base form). This dose was previously used in our lab to investigate the pharmacokinetic properties of colistin following intratracheal administration of colistin sulfate solution in rats [17 (link)]. Pulmonary administrations were performed after a sedation period with isoflurane (3% air at 550 mL min⁻¹ for 10 min). For COLI solution nebulization, 100 µL of INU-COLI solution at a COLI concentration of 1.25 mg mL⁻¹ in saline was spray instilled using the PennCentury MicroSprayer™ aerosolizer (model IA–1B, Penn-Century, Philadelphia, PA, USA). For INU-COLI powder, intratracheal insufflation, around 0.3 mg of powder (0.15 mg of COLI) was delivered in one puff of 2 mL of air using a Dry Powder Insufflator–Model DP-4 (Penn-Century, Philadelphia, PA, USA). The insufflator was weighed with a 0.01 mg accuracy scale (Sartorius KB BA100) before and after insufflation to determine the exact amount of powder delivered, and the dose of colistin administered was calculated based on the animal’s weight.