Pulmonary delivery liquid systems

Some companies are focusing on the development of a new generation of liquid systems that are portable, more efficient, more gentle on the macromolecule and that can deliver the medicine in far fewer puffs than the old fashioned nebulizer. Two companies who are developing advanced pulmonary delivery liquid systems are Aradigm Corporation, Hayward, CA, and AeroGen, Inc., Sunnyvale, CA. 

Pulmonary delivery of insulin for systemic absorption in the treatment of diabetes has been studied extensively since the early days of insulin discovery almost a century ago. Colthorpe et al. and Pillai et al. demonstrated in rabbit and monkey models, respectively, that the deeper into limg the dose of insulin was delivered, the higher was the bioavailability. The work of Laube, Benedict, and Dobs showed the need to achieve deep pulmonary deposition of this molecule for efficient absorption in humans. Handheld liquid and dry powder delivery systems have been developed to generate insulin-containing aerosols with the majority of the particles in the aerodynamic size range 1-3 pm. The relative bioavailability compared with subcutaneous injection based on the insulin contained in the dosage form was 110/ [52] powder system and for the aqueous-based... 

Liquid scrubbing is also known as one of the most efficient methods for very fine-particle collection, but they are gathered in the form of a suspension that can be rather used for nasal, pulmonary, or parenteral delivery. The suspension stability is often a delicate issue because no chemical or biological degradation shall occur, nor particle decantation, which requires the use of complex mixtures, including a buffer (especially for biomolecules), preservatives (antimicrobial, antioxidant, etc.), and surfactants. Several systems have been described (37,86-88) ... 

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