Background: The use of laser methods to irradiate currently used drugs in order to obtain
photo-products with antimicrobial and anti-tumour activity constitutes a new approach in fighting
antimicrobial resistance acquired by bacteria and tumours.
Methods: The interaction of UV laser radiation with phenothiazine derivatives, such as chlorpromazine,
thioridazine and promethazine, and a hydantoin derivative, SZ-2, was evaluated using analytical
techniques: UV-Vis-NIR absorption, FTIR, and laser induced florescence.
Results: The investigation of photo-products mixtures suggested the photo-generation of sulfoxide
and hydroxyl compounds when phenothiazine derivatives were irradiated and the braking of molecule
and detachment of radical attached to thio-hydantoin ring when SZ-2 was irradiated. As for
application of laser irradiated drug solutions on pseudo-tumours induced in rabbit eyes using
Schmidt-Erfurth method, it was observed a decrease of inflammations related to pseudo-tumours
and a fast recovery of corneal tissues.
Conclusion: The best effect concerning the recuperation of healthy corneal tissue quality in the
pseudo-tumour was observed for 10 mg/mL chlorpromazine irradiated 20 min with 266 nm laser
beam. This new method offers the possibility to combat antimicrobial resistance acquired by tumours
or bacteria by flexible development of new agents using laser systems and techniques.