Study treatment
Nebulised UFH was administered through a vibrating mesh nebuliser (NebZmart, Glenmark, Taiwan) with 1.25 ml of the sodium heparin (5,000 IU / 0.25 mL) being diluted with 4 ml of 0.9% saline at 6 hourly intervals in addition to standard of care, with other patients randomised to receive only standard of care as the control arm of the study. Randomisation was 1:1 without any adjustment for any clinical characteristics. Randomisation was produced by using a computerized random list generator.
The UFH used was formulated as ampules containing 5,000 IU/0.25 mL, from Cristalia Ltda, meeting all the requirements of the USP and Brazilian Pharmacopeia (BP). The heparin samples were analyzed by 1D1H-NMR spectroscopy, gel permeation and anion exchange chromatographies and had their anticoagulant potencies determined with anti-FIIa and anti-FXa activity assays, as required by both the USP and BP. The molecular mass distribution parameters of the formulations also met the requirement of USP. Besides certified as being from porcine origin, the formulations showed no contamination with heparins from other animal sources, as recommended by the BP. The 1D1H-NMR spectrum show no signal at 7.4 ppm, assuring the absence of benzyl alcohol commonly added as a preservative in multiuse vials for intravenous administration but not into formulations intended for subcutaneous use. Furthermore, the formulations used showed no contamination with oversulfated chondroitin sulfate after analyses by NMR and anion exchange chromatography.