Pharmaceutical Aerosols

Pharmaceutical and Cosmetic Aerosols

“…Particles between 0.5 and 5.0 pm tend to fall against the alveolar walls and mix with the alveolar fluid (162). It is generally agreed that particles larger than 20 pm fail to go beyond the terminal bronchioles, those 6 pm in diameter are removed before they reach the lower alveolar ducts, and almost all particles 2 pm and larger are removed in the lower alveolar ducts (163). There is only a 50% chance for the deposition of particles 1 pm in size.…”

Dry Powders for Pulmonary Delivery of Peptides and Proteins

“…Those larger than 6 µm fail to reach the alveolar ducts. The optimum particle size to reach and be deposited in the alveolar region seems to be 1 to 5 µm (70,71,74,75). Submicrometer-size particles are exhaled, deposited, or both by random Brownian motion in distal regions.…”

“…When insulin dry powder containing 0.036 mg/dose of citric acid was administered to rat lungs, bronchoalveolar lavage was as low as that for saline administration, suggesting that citric acid is a safe additive (36). Adding an 74 KONA No. absorption enhancer is a promising method for increasing the systemic bioavailability of inhaled peptides and proteins, but long-term safety should be examined for application to humans.…”

“…Particle size and its distribution affect particle retention in the lungs (70,74). Particles larger than 20 µm likely fail to go beyond the terminal bronchioles.…”

Video characterization of flume patterns of inhalation aerosols

“…BACKGROUND Extensive research (3) has been conducted on the relationship of the particle size of an active drug to its distribution and retention in the lungs. The conflict of theories and experimental results has been attributed to such variables as the species of animal used, nonuniform breathing rates, methods of measuring the particle-size distribution, methods of administering the agents used, and the effects of lung moisture content on the size of the inhaled particles (4)(5)(6). However, it generally is agreed that the depth of penetration increases with decreasing particle size while the whole lung retention increases with increasing particle size (7,8).…”