title: The use of organic vapor sorption to determine low levels of amorphous content in processed pharmaceutical powders.
abstract: Organic dynamic vapor sorption (organic-DVS) was used to characterize amorphous content in known amorphous-crystalline mixtures of lactose and salbutamol sulfate. N-octane was chosen as an apolar probe and measurements were carried out by exposing mixtures of each sample to partial pressures 0-90% p/p(0). A linear relationship between amorphous content and n-octane partial pressure was observed for both lactose and salbutamol sulfate with R(2) values of 0.992 and 0.999, respectively. In addition, the influence of sequential mechanical processing in a ball mill on the amorphous content in crystalline lactose was investigated. Cumulative milling times resulted in an exponential increase in amorphous content (using the linear relationship obtained for lactose), with a maximum amorphous content of 14% being induced after 60 min milling. In comparison, analysis of the 60 min mill time samples after exposure to 85% relative humidity suggested 0.00% amorphous content.
authors.affiliation: Advanced Drug Delivery Group, University of Sydney, Sydney, NSW, Australia.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Young
authors.forename: Herbert
authors.initials: H
authors.lastname: Chiou
authors.forename: Terrance
authors.initials: T
authors.lastname: Tee
authors.forename: Daniela
authors.initials: D
authors.lastname: Traini
authors.forename: Hak-Kim
authors.initials: HK
authors.lastname: Chan
authors.forename: Frank
authors.initials: F
authors.lastname: Thielmann
authors.forename: Dan
authors.initials: D
authors.lastname: Burnett
mesh_terms: D000420:Albuterol / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D007785:Lactose / Q000737:chemistry*; D011208:Powders; D013678:Technology, Pharmaceutical; D014835:Volatilization
chemical_list: D011208:Powders; D007785:Lactose; D000420:Albuterol