The permeation properties of twenty newly synthesized α-alkoxyalkanoyl and α-aryloxyalkanoyl C-21 esters of standard corticosteroids: Fluocinolone acetonide, dexamethasone, triamcinolone acetonide and hydrocortisone were established using a PAMPA assay (70% silicone oil and 30% isopropyl myristate). The data were compared with parent corticosteroids with addition of mometasone furoate and hydrocortisone acetate. All newly synthesized corticosteroid C-21 esters have effective permeability coefficients higher then -6, mostly followed with high values of retention factors and low permeation. The examined compounds were grouped through relationship between obtained retention factors and permeation parameters (groups I–III). The classification confirmed group I (membrane retentions as well as permeation lower then 30%) for all corticosteroid standards except mometasone furoate, a potent topical corticosteroid which, with high membrane retention (81%) and low permeation (7.7%) fits into group III. The largest number of new synthesized corticosteroids C-21 esters, among them all fluocinolone acetonide C-21 esters, have high membrane retentions (32.4%–86.5%) and low permeations (1.3%–27.1%), fitting in group III. The classification was related to previously obtained anti-inflammatory activity data for the fluocinolone acetonide C-21 esters series. According to the PAMPA results the new synthesized esters could be considered as potential new prodrugs with useful benefit/risk ratio.

Various dual inhibitors of COX-2 and 5-LOX enzymes have been developed so far in order to obtain more effective and safer anti-inflammatory drugs. The aim of this study was to design and synthesize new dual COX-2 and 5-LOX inhibitors, and to evaluate their enzyme inhibition potential and redox properties. Thirteen compounds (1–13) were designed taking into account structural requirements for dual COX-2 and 5-LOX inhibition and antioxidant activity, synthesized, and structurally characterized. These compounds can be classified as N-hydroxyurea derivatives (1, 2 and 3), 3,5-di-tert-butylphenol derivatives (4, 5, 6, 7 and 13), urea derivatives (8, 9 and 10) and “type B hydroxamic acids” (11 and 12). COX-1, COX-2 and 5-LOX inhibitory activities were evaluated using fluorometric inhibitor screening kits. The evaluation of the redox activity of newly synthesized compounds was performed in vitro in the human serum pool using redox status tests. The prooxidative score, the antioxidative score and the oxy-score were calculated. Seven out of thirteen synthesized compounds (1, 2, 3, 5, 6, 11 and 12) proved to be dual COX-2 and 5-LOX inhibitors. These compounds expressed good COX-2/COX-1 selectivity. Moreover, dual inhibitors 1, 3, 5, 11 and 12 showed good antioxidant properties.

Biopartitioning micellar chromatography (BMC), which is useful to mimic the drug partitioning process in biological systems, was used as a method for determination of partition coefficients micelle/water (P _m/w ) of a set of structurally diverse drugs. BMC is a chromatographic system consisting of polyoxyethylene (23) lauryl ether (Brij 35) micellar mobile phase prepared in physiological conditions and C₁₈ reversed stationary phase. The retention factors were determined for all selected and studied compounds and a correlation between P _m/w and oral drug absorption values were obtained. In order to study the similarity between the BMC system and other natural systems of biomembranes, the retention data on BMC were compared with permeability data obtained in Parallel artificial membrane permeation assays (PAMPA lipid model). Molecular descriptors that are believed to influence transcellular transport and oral drug absorption have been calculated in order to obtain a predictive and reliable model for drug permeability. Results presented in this paper indicate that a proposed descriptor for hydrophobicity P _m/w , provided, from a statistical point of view, is a better model than other hydrophobicity descriptors.

Apart from cytotoxicity, inhibitors of the COX-2 enzyme have demonstrated additional effects important for cancer treatment (such as radiosensitization of tumor cells and cell antimigratory effects); however, the relationship between the inhibition of other inflammation-related enzyme 5-LOX inhibitors and anticancer activity is still not well understood. In our study, the cytotoxicity of thirteen COX-2 and 5-LOX inhibitors previously presented by our group (1–13) was tested on three cancer cell lines (HCT 116, HT-29 and BxPC-3) and one healthy cell line (MRC-5). Compounds 3, 5, 6 and 7 showed moderate cytotoxicity, but good selectivity towards cancer cell lines. IC₅₀ values were in the range of 22.99–51.66 µM (HCT 116 cell line), 8.63–41.20 µM (BxPC-3 cell line) and 24.78–81.60 µM (HT-29 cell line; compound 7 > 100 µM). In comparison to tested, commercially available COX-2 and 5-LOX inhibitors, both cytotoxicity and selectivity were increased. The addition of compounds 6 and 7 to irradiation treatment showed the most significant decrease in cell proliferation of the HT-29 cell line (p < 0.001). The antimigratory potential of the best dual COX-2 and 5-LOX inhibitors (compounds 1, 2, 3 and 5) was tested by a wound-healing assay using the SW620 cell line. Compounds 1 and 3 were singled out as compounds with the most potent effect (relative wound closure was 3.20% (24 h), 5,08% (48 h) for compound 1 and 3.86% (24 h), 7.68% (48 h) for compound 3). Considering all these results, compound 3 stood out as the compound with the most optimal biological activity, with the best dual COX-2 and 5-LOX inhibitory activity, good selectivity towards tested cancer cell lines, significant cell antimigratory potential and a lack of toxic effects at therapeutic doses.

A simple and convenient reversed-phase high-performance liquid chromatography (RP-HPLC) method for simultaneous separation, identification, and determination of sodium metabisulfite and sodium benzoate in pharmaceutical formulation has been developed and validated. Chromatographic separation was achieved on RP column Zorbax Extend C-18 (150 × 4.6 mm i.d., 3.5 μm particles), and mixture of 0.1% phosphoric acid and acetonitrile in the ratio 62:38 (v/v) was used as a mobile phase. The flow rate was set at 1.0 mL/min with detection wavelength of 275 nm. The method was successfully validated according to International Conference on Harmonization (ICH) guidelines acceptance criteria. The method is selective, as no interferences were observed at retention times corresponding to these analytes. Results of regression analyses (r) and statistical insignificance of calibration curve intercepts (p) proved linearity of the method in defined concentration ranges for sodium metabisulfite and sodium benzoate (0.05–0.15 mg/mL). Relative standard deviations calculated for both analytes in precision testing were below the limits defined for active pharmaceutical ingredients (analysis repeatability: <2%; intermediate precision: <3%). Recovery values were between 98.16% and 101.94%. According to results of robustness testing, chromatographic parameters are not significantly influenced by small variation of acetonitrile content in mobile phase, column temperature, and flow rate. Finally, the method was applied for quantitative determination of investigated preservatives in real sample analysis.

Cortienic acid was obtained by periodic acid oxidation of fluocinolone acetonide, whereas corresponding amide was synthesized from the cortienic acid and ethyl ester of b-alanine by dicyclohexylcarbodiimide - hydroxybenzotriazole coupling procedure. Lipophilicity of the amide was evaluated by using reversed-phase thin-layer chromatography systems, consisting of ethanol and water in various ratios, and was higher in comparison to fluocinolone acetonide and cortienic acid.