Preservatives in ophthalmic solutions have long been known to cause toxic effects on the cornea. The most frequently used preservative in eye drops, and one that has among the highest toxicity, is benzalkonium chloride (BAC)[1-3]. This quarternary ammonium has been shown to have a variety of pathological effects, including tear film instability, conjunctival squamous metaplasia, breakdown of co...

PURPOSE To investigate whether optimized photoactivated chromophore for keratitis-corneal collagen cross-linking (PACK-CXL) treatment settings allow accelerating treatment while maintaining antibacterial efficacy. METHODS Staphylococcus aureus and Pseudomonas aeruginosa strains were irradiated with ultraviolet-A light of equal fluence but different intensity settings (18 mW/cm² for 5 minutes ...

UNLABELLED This study aimed to assess the membrane modifications in Pseudomonas aeruginosa after continuous exposure to increasing doses of benzalkonium chloride (BC). Two different concentrations were used, 0.9 and 12.0mM. Proteomic investigations revealed that the range of the outer membrane proteome alterations following continuous exposure is very low, i.e. about 10% and BC concentration de...

The prediction of side-effects is a key issue in the REACH initiative on chemicals, in the production of cosmetics and in the preclinical testing of drugs. A new ex vivo test for repeated substance application is presented, that is able to identify corrosive and irritant effects on the eye by using crucial endpoints, such as cellular and morphological damage, and healing characteristics. The te...

PURPOSE To characterize the effects of benzalkonium chloride (BAK) in THP-1 differentiated cells in vitro. METHODS Macrophages were obtained after differentiation of THP-1 cells, a human monocytic leukemia cell line. Macrophages were exposed for 24 h to 33 nM (10(-5)%) benzalkonium chloride (BAK), 10 nM dinitrochlorobenzene (DNCB), 100 ng/mL lipopolysaccharide (LPS), 5 ng/mL tumor necrosis fa...

(a) bactericidal and fungicidal, (b) compatible with most chemicals used in ophthalmic preparations, (c) non-irritating and non-sensitizing. The most commonly accepted preservative is the mixture of methyl and propylhydroxybenzoates used in the " Solution for Eye-Drops" of the British Pharmaceutical Codex. These hydroxybenzoates, being relatively efficient fungicides, will keep the solutions fr...

Non-muscle-invasive urothelial carcinoma of the bladder has a high rate of recurrence, necessitating use of a variety of adjuvant treatments. A single, immediate post-operative administration of chemotherapy is an important measure for reducing the rate of recurrences, but the overall effect is not satisfactory and the treatment is a burden to the patient. Hence, there is a need for a new, more...