The use of organic vapor sorption to determine low levels of amorphous content in processed pharmaceutical powders.
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.
Young
Paul M
PM
Advanced Drug Delivery Group, University of Sydney, Sydney, NSW, Australia.
Chiou
Herbert
H
Tee
Terrance
T
Traini
Daniela
D
Chan
Hak-Kim
HK
Thielmann
Frank
F
Burnett
Dan
D
D000420:Albuterol / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D007785:Lactose / Q000737:chemistry*; D011208:Powders; D013678:Technology, Pharmaceutical; D014835:Volatilization
D011208:Powders; D007785:Lactose; D000420:Albuterol