Cw. Lin et Tm. Cham, COMPRESSION BEHAVIOR AND TENSILE-STRENGTH OF HEAT-TREATED POLYETHYLENE GLYCOLS, International journal of pharmaceutics, 118(2), 1995, pp. 169-179
The compression behavior and tensile strength of five heat-treated pol
yethylene glycol (PEG) powders of different average molecular weights
were determined. Compacts were prepared at various compression pressur
es using three different size fractions. The compression behavior of t
he compacts was analyzed according to the Kawakita, Cooper-Eaten and H
eckel methods, respectively, and their compression parameters were cal
culated. Compared to the other polymers, PEG 4000 underwent greater de
nsification during compression. The yield pressure from the slope of t
he Cooper-Eaten plot was lowest for PEG 4000. The yield pressure deter
mined via the Heckel method was found to be proportional to the molecu
lar weight of the PEG. These polymers obey a Heckel relationship at lo
wer pressures (not exceeding 80 MN/m(2)) and exhibit a behavior simila
r to those of fatty acid powders. The specific surface area of the com
pacts decreased with increasing compression pressure. The change in sp
ecific surface area of compacts compressed at pressures greater than 8
0 MN/m(2) was only very slight. This indicates that the surface of the
compacts melts at such pressures. At pressures above 26.53 MN/m(2), P
EG 10 000 compacts had superior tensile strength compared to the other
polymers.