Evaluation of physicochemical properties and bacterial photoinactivation of phenothiazine photosensitizers.

VARA, J.; GUALDESI, M.S.; AIASSA V; ORTIZ, C.S.

Photochemical and Photobiological Sciences

ROYAL SOC CHEMISTRY

Lugar: CAMBRIDGE; Año: 2019

1474-905X

e report herein the physicochemical properties and antimicrobial activity of a new monobrominatedderivative of Azure B and its parent compound. These dyes are used as photosensitizers for photodynamictherapy and photodynamic antimicrobial chemotherapy. Relevant pharmaceutical properties (pKa, chemicaland photochemical stability, and in vitro antimicrobial activity) were determined. A UV?visible spectrophotometrymethod was developed and validated according to the International Conference onHarmonization (ICH) guidelines for use in stability indicating studies and determination of the acid dissociationconstant of Azure B and its monobrominated derivative. The results showed that both dyes werechemically stable. In addition, bromination of the phenothiazine dye decreased its photochemical stabilityand pKa value without affecting the ionization rate at physiological pH. The analytical parameters for validationof the method were linearity (r2 > 0.9981), limit of detection (LOD) (0.2?0.9 &#