HPLC detection and quantification of radiolytic products of 8
b-blockers irradiated in the solid state and hypotheses on their
origins.
Pharmaceut. Res. 27, 1103-1108 (2004).
A. Engalytcheff, J.-P. Vanhelleputte, B. Tilquin
Laboratory of Chemical and Physicochemical Analysis of Drugs ,
Université Catholique de Louvain, Brussels, Belgium
Purpose : The radiolytic products of eight b-blockers were studied in
order to understand the mechanisms of irradiation of drugs in the solid
state.
Methods : The drugs were analyzed by high performance liquid
chromatography coupled to a diode array detector in order to observe
the degradation of the main compound after irradiation and in order to
study the non-volatile final products on more concentrated solutions of
irradiated drugs.
Results : The first test assessed that the main compound was not
significantly degraded after gamma irradiation for any of the eight
b-blockers. A more complete study, that consisted on separating the
non-volatile products and on quantifying them, indicated first that the
radiolytic products could reach the number of 14 and moreover that some
could exceed the 0.1% threshold at 30 kGy. Eventually, radiolytic
yields were compared with radical yields previously determined.
Conclusions : The sensitivity of the first test can be discussed. It
seems that, to study the feasibility of the radiosterilization, a
complete study of the products of degradation is needed. Moreover, no
correlation between radical and final products could be established,
which denies that the former would be the precursors of the latter.