Effects of IB–MP
(A), DIC–MP (B), and KET–MP
(C) on the activity of ovine COXI and human COXII in the absence/presence
of porcine liver esterase (PLE). Their activities were compared to
the inhibitory effect of authentic samples of ibuprofen (IB) (A),
diclofenac (DIC) (B), and ketoprofen (KET) (C). Absorption spectrum
of each prodrug IB–MP (D), DIC–MP (E), and KET–MP
(F) in the presence of porcine liver esterase (PLE) was monitored
every 4 min for 100 min. The dashed line represents an initial absorbance
spectrum before the addition of PLE. In each spectrum, one labeled
line represents a spectrum of propyphenazone (PP), and the other labeled
line depicts the absorption of an authentic sample of IB (D), DIC
(E), and KET (F). The arrows indicate the direction of the spectral
change over time.