Antibacterial graphene-based hydroxyapatite/chitosan coating with gentamicin for potential applications in bone tissue engineering.

Electrophoretic deposition process (EPD) was successfully used for obtaining graphene (Gr)-reinforced composite coating based on hydroxyapatite (HAP), chitosan (CS), and antibiotic gentamicin (Gent), from aqueous suspension. The deposition process was performed as a single step process at a constant voltage (5 V, deposition time 12 min) on pure titanium foils. The influence of graphene was examined through detailed physicochemical and biological characterization.

Gentamicin-Loaded Bioactive Hydroxyapatite/Chitosan Composite Coating Electrodeposited on Titanium.

Composite coating of antibiotic gentamicin (Gent), natural polymer chitosan (CS), and hydroxyapatite (HAP) was successfully assessed by applying the electrophoretic deposition (EPD) technique. EPD was performed under optimized deposition conditions (5 V, 12 min) on pure titanium plates, to obtain HAP/CS and HAP/CS/Gent composite coatings in a single step from three-component aqueous suspension, with favorable antibacterial properties. Composite coatings were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray photoelectron analysis, confirming the formation of composite HAP/CS and HAP/CS/Gent coatings on the titanium surface, which is due to intermolecular hydrogen bonds.

Evaluation of angiotensin-converting enzyme inhibitor's absorption with retention data of micellar thin-layer chromatography and suitable molecular descriptor.

Twelve angiotensin-converting enzyme (ACE) inhibitors were studied to evaluate correlation between their absorption (ABS) data available in the literature (22-96%) and hydrophobicity parameters (km and Pm/w) obtained in micellar thin-layer chromatography (MTLC) using Brij 35. The theoretical considerations showed that the geometric molecular descriptor-volume value (Vol) should be considered as an independent variable simultaneously with calculated hydrophobicity parameters in multiple linear regression analysis to obtain reliable correlation between ACE inhibitor's absorption and lipophilicity (calculated KOWWINlog P) and that captopril should be excluded from further correlations. The results of MTLC confirmed that between the two hydrophobicity parameters km and Pm/w, for absorption prediction of 11 ACE inhibitors, the micelle-water partition coefficient Pm/w provided higher correlation (R(2) = 0.

Estimation of angiotensin-converting enzyme inhibitors protein binding degree using chromatographic hydrophobicity data.

Introduction: Angiotensin-converting enzyme (ACE) inhibitors represent a significant group of drugs primarily used in the treatment of hypertension and congestive heart failure.

Objective: Selected ACE inhibitors (enalapril, quinapril, fosinopril, lisinopril, cilazapril) were studied in order to establish a fast and easy estimation method of their plasma protein binding degree based on their lipophilicity data.

Methods: Chromatographic hydrophobicity data (parameter C0) were obtained on cellulose layers under conditions of normal-phase thin-layer chromatography (NPTLC), using different binary solvent systems.

In vitro modeling of angiotensin-converting enzyme inhibitor's absorption with chromatographic retention data and selected molecular descriptors.

Set of nine angiotensin-converting enzyme inhibitors (enalapril, quinapril, fosinopril, lisinopril, cilazapril, ramipril, benazepril, perindopril and moexipril) were studied to evaluate the correlation between their intestinal absorption and salting-out thin-layer chromatography hydrophobicity parameters (RM(0) or C0) obtained by ascending technique applying four different salts, (NH4)2SO4, NH4NO3, NH4Cl and NaCl as mobile phases. The best correlations between KOWWIN logP and both hydrophobicity parameters, RM(0) and C0, (R(2)>0.850) were observed for NaCl (1.

Correlation between ultra-high performance liquid chromatography-tandem mass spectrometry and reversed-phase thin-layer chromatography hydrophobicity data for evaluation of angiotensin-converting enzyme inhibitors absorption.

In this research seven ACE inhibitors (enalapril, quinapril, fosinopril, lisinopril, cilazapril, ramipril, benazepril) were studied to evaluate the correlation between their absorption and ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS) and reversed-phase thin-layer chromatography (RP-TLC) hydrophobicity data (φ(0) or C(0) parameters, respectively). Their absorption values were in the range of 25-60%, while calculated KOWWIN logP values were from -0.94 to 6.

Lipophilicity Examination of Some ACE inhibitors andHydrochlorothiazide on Cellulose in RP Thin-Layer Chromatography.

In this assay, the evaluation of lipophilicity of four ACE-inhibitors and hydrochlorothiazide (HCTZ) with RP-TLC on cellulose layers was described using three binary solvent systems. The selected ACE inhibitors had sufficiently different structures which can indicate the method suitability for their lipophilicity evaluation as the model substances in comparison with HCTZ. In addition, the linear relationship between the RM-values and composition of mobile phases was established in the current study.

A PAMPA assay as fast predictive model of passive human skin permeability of new synthesized corticosteroid C-21 esters.

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.