Current Issue : July-September Volume : 2026 Issue Number : 3 Articles : 5 Articles
Objectives: The aim of the work was to present a method for routine determination of antiarrhythmic drugs, propafenone (PPF), its two metabolites, 5-hydroxypropafenone (5OHPPF) and N-depropylpropafenone (NDPPF), mexiletine (MEX), amiodarone (AD) and desethylamiodarone (DEAD) in serum. Methods: A simple isocratic HPLC-UV system with a manual injector was applied. The separations were performed at ambient temperature on Supelcosil LC-CN column (150 × 4.6 mm, 5 μm). Two analytical procedures (A and B) were used: (A) for AD and (B) for PPF/MEX. The mobile phase for (A) was a mixture of: CH3OH:CH3CN:H2O:0.5M KH2PO4 (200:100:194:6 v/v + 0.1 mL 85% H3PO4 per 500 mL). The slightly acidified serum sample was extracted with hexane and the analytes were detected at 240 nm. The mobile phase for (B) was a mixture of: CH3CN:H2O:0.5M KH2PO4 (185:310:5 v/v + 0.1 mL 85% H3PO4 per 500 mL). The alkalized serum sample was extracted with diisopropyl ether, then back extracted into 0.01M HCl and finally the analytes were detected at 210 nm. Results: The method was calibrated with adequate selectivity and specificity in the range of 20–4000 ng/mL for AD, DEAD and MEX, 10–4000 ng/mL for PPF and 10–500 ng/mL for 5OHPPF and NDPPF. For all analytes, precision and accuracy fulfilled EMA requirements, i.e., ≤15% (≤20% for LLOQ), ensuring the reliability of the measurements. Conclusions: The method can be suitable for laboratories equipped with basic HPLC apparatus as an economical alternative to the LC-MS/MS technique....
A simple, rapid, and cost-effective UV–Vis spectrophotometric method was developed and validated for the determination of levofloxacin in rat plasma to support the evaluation of a novel antimicrobial mesh implant containing levofloxacin, chitosan, gelatin, tinctura propolis, citric, acid and glycerin. Plasma samples were treated with 0.1 M HCl, and absorbance was measured at 290 nm. The method was validated according to FDA and ICH guidelines, including assessments of linearity, sensitivity, accuracy, precision, and specificity. The calibration curve was linear over the concentration range of 2.5–12.5 μg/mL (R2 = 0.999, p < 0.001). The limit of detection and limit of quantification were 0.21 μg/mL and 0.62 μg/mL, respectively. Intra- and inter-day precision showed low relative standard deviation values (0.2% and 0.25%), while recovery ranged from 94.8% to 96.4%, confirming acceptable accuracy. No significant interference from plasma matrix components was observed. Compared with chromatographic techniques, the proposed method provides an accessible alternative for routine bioanalysis and therapeutic monitoring. The validated assay is suitable for assessing prolonged levofloxacin release from implantable drug delivery systems in preclinical studies....
Background: Gingivitis and periodontitis are progressive inflammatory diseases affecting the tissues surrounding the teeth; gingivitis involves reversible gingival inflammation, whereas periodontitis is a more advanced condition characterized by irreversible tissue destruction, including clinical attachment and alveolar bone loss. Salusin-α and salusin-β are inflammation-related polypeptides that may reflect periodontal inflammatory burden; however, salivary data in periodontal diseases are lacking. This study aimed to evaluate the salivary salusin-α and salusin-β levels in individuals with gingivitis and periodontitis. Methods: Saliva samples were collected from a total of 80 systemically healthy non-smoker individuals classified into three groups: gingivitis (n = 27), stage III grade B periodontitis (n = 27), and healthy participant (n = 26) based on the 2017 Periodontal Classification criteria. Salusin-α and salusin-β levels in saliva were quantified using enzyme-linked immunosorbent assays (ELISA). Statistical analysis utilized one-way ANOVA, Student’s t-test, and Receiver Operating Characteristic (ROC) curve analysis. Results: Compared to the healthy group, salivary levels of salusin-α and salusin-β were found to be significantly elevated in periodontitis groups (p < 0.05), not gingivitis (p > 0.05); moreover, the increase in both markers was significantly greater in the periodontitis group than in the gingivitis group (p < 0.05). Conclusions: Our finding suggests that salusins play a role in the inflammatory processes of periodontal diseases. The increase in salusin-α and salusin-β levels in the periodontitis suggests that these parameters may serve as biomarkers....
The excessive use of phytosanitary products represents a growing concern, due to their persistence and potential environmental and toxicological impacts. Among these compounds, glyphosate, a glycine-derived chemical marketed as a broad-spectrum herbicide, is one of the most widely used pesticides worldwide. Breast milk is a complex biological matrix that can reflect environmental exposure, making it highly suitable for assessing glyphosate contamination. This study aimed to demonstrate a screening method to determine glyphosate concentrations in the breast milk of 100 postpartum women residing in Tupã, São Paulo, Brazil—90 in urban areas and 10 in rural areas—using high-performance liquid chromatography (HPLC) for rapid detection. By validation parameters, it was possible to verify, through the correlation coefficient (r), that the method is linear within the working range; the LD was 0.14 mg/L and the LQ was 0.43 mg/L. The recovery obtained by standard sample fortification was 92%. All analyzed samples presented detectable levels of glyphosate, indicating consistent exposure patterns and suggesting relevant environmental contamination routes in the region. These findings provide evidence of glyphosate presence in human milk and reinforce the importance of continuous monitoring strategies and preventive public health measures aimed at reducing exposure to agricultural contaminants....
Introduction: Plasma is the standard biological fluid used in pharmacokinetic (PK) studies and therapeutic drug monitoring (TDM) of pyrazinamide, a key antituberculosis (TB) drug. This study described the PK of pyrazinamide in saliva and investigated whether saliva could serve as an alternative matrix for pyrazinamide PK evaluations. Methods: Fifteen adult Tanzanian TB patients in the intensive treatment phase participated in a descriptive PK study. Time-matched saliva (stimulated using a Salivette® with citric acid) and plasma samples were collected at multiple intervals up to 24 h after drug intake. Pyrazinamide concentrations were measured using validated HPLC methods, exposure measures were assessed, and predictive performance for salivary concentrations was determined. Results: Salivary exposure to pyrazinamide (AUC0–24h: 230 h·mg/L; Cmax: 28.6 mg/L) was lower than plasma exposure (AUC0–24h: 377 h·mg/L; Cmax: 36.4 mg/L, p < 0.001), but Tmax was similar (median 2.0 h, p = 0.893). A saliva/plasma ratio of 0.59 was assessed, and a reciprocal conversion factor of 1.68 allowed for reasonably accurate (bias 5.8%) but imprecise (imprecision 24.3%) plasma concentration predictions from saliva. Use of a conversion factor of 1.49, based on more stable saliva/plasma concentration ratios for samples between 2 and 6 h post-dose, resulted in a bias of 0.74% and imprecision of 17.7% for predicting plasma concentrations from salivary concentrations in the 2–6 h interval. Conclusions: The exposure to pyrazinamide in saliva is relatively high. Salivary measurement of pyrazinamide can be used as a semi-quantitative predictor of pyrazinamide plasma concentrations....
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