title: Influence of the valve lubricant on the aerodynamic particle size of a metered dose inhaler.
abstract: Presented in this work are the results of a study designed to investigate the impact of valve lubricant (i.e., silicone oil) on the aerodynamic particle size distribution (PSD) of a steroid suspension metered dose inhaler (MDI) containing propellant HFA-227. The objective of this study was to explore whether the valve lubricant, which is often used in MDI products to prevent valve sticking, can enter an MDI product and potentially impact the aerosol spray dynamics. The results of this work have shown that samples containing valves with high silicone levels produced a larger aerodynamic particle size (by cascade impaction) than samples with low-silicone or silicone-free valves. It is postulated that the presence of silicone in the product may increase the propensity for drug aggregation, thereby leading to an increase in the aerodynamic particle size of the emitted aerosol. These findings stress the importance of evaluating the effects of valve lubricant on the aerodynamic PSD in the early formulation development stage of an MDI.
authors.affiliation: Schering Plough Research Institute, Kenilworth, New Jersey 07033, USA. julianne.berry@spcorp.com
authors.forename: Julianne
authors.initials: J
authors.lastname: Berry
authors.forename: Lukeysha
authors.initials: L
authors.lastname: Kline
authors.forename: Venkatesh
authors.initials: V
authors.lastname: Naini
authors.forename: Saeed
authors.initials: S
authors.lastname: Chaudhry
authors.forename: John
authors.initials: J
authors.lastname: Hart
authors.forename: Joel
authors.initials: J
authors.lastname: Sequeira
mesh_terms: D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000737:chemistry; D000335:Aerosol Propellants / Q000737:chemistry; D000336:Aerosols; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry; D008153:Lubrication; D036501:Metered Dose Inhalers; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D012828:Silicones / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry; D013535:Suspensions; D013678:Technology, Pharmaceutical; D005466:Fluorocarbons
chemical_list: D000305:Adrenal Cortex Hormones; D000335:Aerosol Propellants; D000336:Aerosols; D006845:Hydrocarbons, Fluorinated; D012828:Silicones; D013501:Surface-Active Agents; D013535:Suspensions; C094049:apaflurane; D005466:Fluorocarbons