Laser Modified Phenothiazines and Hydantoins: Photo-products Characterisation and Application on Animal Eyes Pseudo-tumours

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.