Preparation and characterization of spray-dried tobramycin powders containing nanoparticles for pulmonary delivery

Laboratory of Pharmaceutics and Biopharmaceutics, Université Libre de Bruxelles, Belgium.
International Journal of Pharmaceutics (Impact Factor: 3.65). 09/2008; 365(1-2):162-9. DOI: 10.1016/j.ijpharm.2008.08.014
Source: PubMed


Using high-pressure homogenization and spray-drying techniques, novel formulations were developed for manufacturing dry powder for inhalation, composed of a mixture of micro- and nanoparticles in order to enhance lung deposition. Particle size analysis was performed by laser diffraction. Spray-drying was applied in order to retrieve nanoparticles in dried-powder state from tobramycin nanosuspensions. The aerolization properties of the different formulations were evaluated by a multi-stage liquid impinger. Suspensions of nanoparticles of tobramycin containing Na glycocholate at 2% (w/w) relative to tobramycin content and presenting a mean particle size about 200 nm were produced. The results from the spray-dried powders showed that the presence of nanoparticles in the formulations improved particle dispersion properties during inhalation. The fine particle fraction (percentage of particles below 5 microm) increased from 36% for the raw micronized tobramycin material to about 61% for the most effective formulation. These new nanoparticle-containing tobramycin DPI formulations, based on the use of very low level of excipient and presenting high lung deposition properties, offer very important perspectives for improving the delivery of drugs to the pulmonary tract.

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Available from: Karim Amighi, Jul 04, 2014
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    • "Powders were precisely weighed and filled in a measuring cylinder before tapping for 1000 times; the tapped density was then calculated by the Eq. (3) (Minne et al., 2008; Mollmann et al., 2006; Pilcer et al., 2009; Sarmento et al., 2006; Silva et al., 2006). Measurements were performed in triplicate. "
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    • "Various methods can be used to prepare polymer nanospheres, such as microemulsion, interfacial polymerization, miniemulsion, salting out, dialysis, super critical fluid technology surfactant-free emulsion, and solvent evaporation.13 Spray drying is a well-known, quick, one-step process frequently used in the pharmaceutical industry to produce a dry powder from a liquid form.14 "
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    • "A direct delivery of inhaled antibiotic to the airways has been suggested. In recent years, inhaled form of tobramicin have been developed specifically for CF treatment (Konstan et al., 2010; Parlati et al., 2009; Pilcer et al., 2009); moreover, a pilot study (Crowther Labiris et al., 1999) has reported that a gentamicin/lactose 1:1 DPI is able to achieve the minimum inhibitory concentration (MIC) in the sputum and a minimal blood concentrations, below toxicity levels. However, to reach the effective dose of 160 mg, 32 actuations of the device were necessary. "
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