Background: The effectiveness of inhaled aerosolized antibiotics is limited by poor ventilation of infected airways. Pulmonary delivery of antibiotics emulsified within liquid perfluorocarbon [antibacterial perfluorocarbon ventilation (APV)] may solve this problem through better airway penetration and improved spatial uniformity. However, little work has been done to explore emulsion formulation and the corresponding effects on drug delivery during APV. This study investigated the effects of emulsion formulation on emulsion stability and the pharmacokinetics of antibiotic delivery via APV.
Methods: Gravity-driven phase separation was examined in vitro by measuring emulsion tobramycin concentrations at varying heights within a column of emulsion over 4 hours for varying values of fluorosurfactant concentration (Cfs = 5-48 mg/mL H2O). Serum and pulmonary tobramycin concentrations in rats were then evaluated following pulmonary tobramycin delivery via aerosol or APV utilizing sufficiently stable emulsions of varying aqueous volume percentage (Vaq = 1%-5%), aqueous tobramycin concentration (Ct = 20-100 mg/mL), and Cfs (15 and 48 mg/mL H2O).
Results: In vitro assessment showed sufficient spatial and temporal uniformity of tobramycin dispersion within emulsion for Cfs ≥15 mg/mL H2O, while lower Cfs values showed insufficient emulsification even immediately following preparation. APV with stable emulsion formulations resulted in 5-22 times greater pulmonary tobramycin concentrations at 4 hours post-delivery relative to aerosolized delivery. Concentrations increased with emulsion formulations utilizing increased Vaq (with decreased Ct) and, to a lesser extent, increased Cfs.
Conclusions: The emulsion stability necessary for effective delivery is retained at Cfs values as low as 15 mg/mL H2O. Additionally, the pulmonary retention of antibiotic delivered via APV is significantly greater than that of aerosolized delivery and can be most effectively increased by increasing Vaq and decreasing Ct. APV has been further proven as an effective means of pulmonary drug delivery with the potential to significantly improve antibiotic therapy for lung disease patients.
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http://dx.doi.org/10.1089/jamp.2015.1235 | DOI Listing |
Int J Pharm
January 2025
CIDETEC, Basque Research and Technology Alliance (BRTA), Parque Científico y Tecnológico de Gipuzkoa, Donostia-San Sebastián, Spain; Kusudama Therapeutics SA, Parque Científico y Tecnológico de Gipuzkoa, Donostia-San Sebastián, Spain; Biogipuzkoa Health Research Institute, Group of Innovation, 20014 San Sebastian, Spain.
Cystic fibrosis (CF) is characterized by abnormal mucus hydration due to a defective CF Transmembrane Regulator (CFTR) protein, leading to the production of difficult-to-clear mucus. This causes airflow obstruction, recurrent infections, and respiratory complications. Chronic lung infections are the leading cause of death for CF patients and inhaled tobramycin is the first-in-line antibiotic treatment against these infections, mainly caused by Pseudomonas aeruginosa in adult patients.
View Article and Find Full Text PDFPharmaceutics
January 2025
School of Pharmacy, Queen's University Belfast, Belfast BT9 7BL, UK.
This paper presents a comprehensive review of the current literature, clinical trials, and products approved for the delivery of antibiotics to the lungs. While there are many literature reports describing potential delivery systems, few of these have translated into marketed products. Key challenges remaining are the high doses required and, for powder formulations, the ability of the inhaler and powder combination to deliver the dose to the correct portion of the respiratory tract for maximum effect.
View Article and Find Full Text PDFNPJ Antimicrob Resist
February 2024
National Heart and Lung Institute, Imperial College London, London, UK.
Antimicrobial peptides (AMPs) are key components of innate immunity across all domains of life. Natural and synthetic AMPs are receiving renewed attention in efforts to combat the antimicrobial resistance (AMR) crisis and the loss of antibiotic efficacy. The gram-negative pathogen Pseudomonas aeruginosa is one of the most concerning infecting bacteria in AMR, particularly in people with cystic fibrosis (CF) where respiratory infections are difficult to eradicate and associated with increased morbidity and mortality.
View Article and Find Full Text PDFJ Antimicrob Chemother
December 2024
Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, CT, USA.
Background: Murine pneumonia models play a fundamental role in the preclinical development of novel compounds seeking an indication for the treatment of pneumonia. It is vital that plasma exposures in these models are not used as a surrogate for exposure in pulmonary epithelial lining fluid (ELF). Herein, human-simulated regimens (HSRs) in both plasma and ELF of meropenem, cefiderocol and tobramycin are described in the standardized COMBINE murine neutropenic pneumonia model.
View Article and Find Full Text PDFFront Immunol
December 2024
Fourth Department of Critical Care Medicine, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou University Affiliated Provincial Hospital, Fuzhou, Fujian, China.
Invasive aspergillosis (IA) significantly increases mortality in critically ill patients in the ICU and its occurrence is closely related to immunocompromise. Dissemination of IA is easily misdiagnosed and mistreated due to its ability to invade multiple systems throughout the body and lack of typical clinical manifestations. In this case, a 25-year-old previously healthy woman was hospitalized with fulminant myocarditis and treated with veno-arterial extracorporeal membrane pulmonary oxygenation (VA-ECMO) support and intravenous acyclovir, high-dose methylprednisolone, and immunoglobulin.
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