Inhaled antibiotics such as colistin and ciprofloxacin are increasingly used to treat bacterial lung in-fections in cystic fibrosis patients.In this study,we established and validated a new HPLC-MS/MS method that could simultaneously detect drug concentrations of ciprofloxacin,colistin and ivacaftor in rat plasma,human epithelial cell lysate,cell culture medium,and drug transport media.An aliquot of 200 μL drug-containing rat plasma or cell culture medium was treated with 600 μL of extraction solution(acetonitrile containing 0.1％ formic acid and 0.2％ trifluoroacetic acid (TFA)).The addition of 0.2％ TFA helped to break the drug-protein bonds.Moreover,the addition of 0.1％ formic acid to the transport medium and cell lysate samples could significantly improve the response and reproducibility.After vortexing and centrifuging,the sample components were analyzed by HPLC-MS/MS.The multiple re-action monitoring mode was used to detect the following transitions:585.5-101.1 (colistin A),578.5-101.1 (colistin B),393.2-337.2 (ivacaftor),332.2-314.2 (ciprofloxacin),602.3-101.1 (polymyxin 81 as internal standard (IS)) and 595.4-101.1 (polymyxin B2 as IS).The running time of a single sample was only 6 min,making this a time-efficient method.Linear correlations were found for colistin A at 0.029-5.82 μg/mL.colistin B at 0.016-3.14 μg/mL.ivacaftor at 0.05-10.0 μg/mL,and ciprofloxacin at 0.043-8.58 μg/mL.Accuracy,precision,and stability of the method were within the acceptable range.This method would be highly useful for research on cytotoxicity,animal pharmacokinetics,and in vitro drug delivery.

Amorphous solid dispersions (ASDs) are popular for enhancing the solubility and bioavailability of poorly water-soluble drugs. Various approaches have been employed to produce ASDs and novel techniques are emerging. This review provides an updated overview of manufacturing techniques for preparing ASDs. As physical stability is a critical quality attribute for ASD, the impact of formulation, equipment, and process variables, together with the downstream processing on physical stability of ASDs have been discussed. Selection strategies are proposed to identify suitable manufacturing methods, which may aid in the development of ASDs with satisfactory physical stability.