PT  - JOURNAL ARTICLE
AU  - Ludwig, John D.
AU  - Avis, Kenneth E.
TI  - Dry Heat Inactivation of Rough Strain Lipopolysaccharide and Diphosphoryl Lipid A on the Surface of Glass
DP  - 1991 Jan 01
TA  - PDA Journal of Pharmaceutical Science and Technology
PG  - 35--40
VI  - 45
IP  - 1
4099  - http://journal.pda.org/content/45/1/35.short
4100  - http://journal.pda.org/content/45/1/35.full
SO  - PDA J Pharm Sci Technol1991 Jan 01; 45
AB  - The thermal inactivation of rough strain lipopolysaccharide (LPS) and diphosphoryl lipid A on the surface of glass capillary tubes was studied. Samples were exposed to precisely controlled dry heat conditions at study temperatures of 225° and 250°C, and were assayed using the gel-clot method of the Limulus Amebocyte Lysate test. Semilog plots of the data revealed apparently biphasic inactivation profiles with large rates of decrease in the initial slopes followed by much slower rates of decline in the terminal slopes. The destruction data were successfully fit to a second-order kinetic equation, and to a biexponential expression. D values were estimated from the initial slopes of the data plots. The rough LPS and diphosphoryl lipid A underwent a 5 log unit reduction in approximately ¼ the time required for smooth strain endotoxin (2). This suggests that the presence of the core polysaccharide and the O-specific antigen regions of the endotoxin substantially increase the heat resistance of the lipid A region, perhaps by a physical shielding effect.