The ideal drug delivery system: a look into the future

Area of Science:

• Pharmaceutical Technology
• Environmental Science

Background:

• Chlorofluorocarbons (CFCs) are widely used as propellants in aerosol products.
• The Montreal Protocol mandates the phase-out of CFC production due to their ozone-depleting properties.

Purpose of the Study:

• To review alternative propellant technologies and devices for aerosol formulations.
• To assess the suitability of new propellants and delivery systems for various applications, including pulmonary administration.

Main Methods:

• Review of existing and emerging propellant technologies, including fluorinated alternatives, hydrocarbons, and compressed air.
• Analysis of novel spray device designs, such as bag-on-valve systems and hand-operated pumps.
• Evaluation of particle size, dose delivery, and potential for pulmonary administration.

Main Results:

• Development of alternative propellants like fluorinated compounds, hydrocarbons (butane, propane), and compressed air is underway.
• New device systems include bag-on-valve technology and manual spray pumps.
• While some systems can generate fine particles, many lack metered valves, limiting their use for pulmonary drug delivery.

Conclusions:

• The transition away from CFCs necessitates the development and validation of safe and effective alternative propellants and delivery systems.
• Current alternative technologies show promise but require further refinement, particularly in dose control and suitability for metered-dose inhalers.
• Continued research is crucial to ensure the availability of viable aerosol formulations for medical and other applications post-CFC phase-out.