Lecithin inverse microemulsions for the pulmonary delivery of polar compounds utilizing dimethylether and propane as propellants
| Autor: | Charles S. Johnson, Anthony J. Hickey, Judith B. Cain, Mark L. Sommerville |
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| Rok vydání: | 2000 |
| Předmět: |
Methyl Ethers
food.ingredient Magnetic Resonance Spectroscopy Chemical Phenomena Pharmaceutical Science Lecithin chemistry.chemical_compound Propane food Drug Delivery Systems Pressure Microemulsion Dimethyl ether Solubility Lung Chromatography Chemistry Physical technology industry and agriculture General Medicine Cobalt Microspheres Solvent Hexane chemistry Aerosol Propellants Critical micelle concentration Phosphatidylcholines Solvents lipids (amino acids peptides and proteins) Emulsions Hydrate Nuclear chemistry |
| Zdroj: | Pharmaceutical development and technology. 5(2) |
| ISSN: | 1083-7450 |
| Popis: | Lecithin inverse microemulsions were investigated as a means of pulmonary drug delivery, utilizing dimethylethyleneglycol (DMEG) and hexane as models for dimethyl ether (DME) and propane, respectively. Addition of lecithin to the model propellant mixtures increased the solubility of water in a nonlinear, solvent-dependent manner. The concentration of water necessary to fully hydrate cobalt(II) decreased as the solvent composition was varied from DMEG to hexane. Water proton chemical shift increased in the presence of lecithin, with the largest increases in high hexane content samples. Equilibrium dialysis and component diffusion rate determination (by pulsed-field gradient [PFG]-NMR) indicated the quantity of water associated with the dispersed phase. Collectively, these methods demonstrated that a greater fraction of water was associated with the microemulsion-dispersed phase as the solvent was varied from DMEG to hexane. Iodine solubilization indicated microemulsion formation (operational critical micelle concentration [cmc], 10 moles water per mole lecithin) at approximately 10(-4)-10(-5) molal lecithin. NMR data (trimethylammonium proton chemical shift, water, and lecithin T1) were consistent with microemulsion formation. Water-soluble compounds dissolved in lecithin inverse microemulsions in a lecithin- and water-dependent manner. Experiments with DME/lecithin demonstrated microemulsion characteristics similar to those in the model propellant. DME/lecithin metered-dose inhalers (MDIs) produced a particle size and a fine particle fraction (36% by twin impinger method) suitable for pulmonary drug delivery. |
| Databáze: | OpenAIRE |
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