How Azide Ion/Hydrazoic Acid Passes Through Biological Membranes: An Experimental and Computational Study.

Hydrazoic acid (HN) and its deprotonated form azide ion (N) (AHA) are toxic because they inhibit the cytochrome c oxidase complex IV (CoX IV) embedded in the inner mitochondrial membrane that forms part of the enzyme complexes involved in cellular respiration. Critical to its toxicity is the inhibition of CoX IV in the central nervous system and cardiovascular system. Hydrazoic acid is an ionizable species and its affinity for membranes, and the associated permeabilities, depend on the pH values of aqueous media on both sides of the membranes.

8-Hydroxyquinolylnitrones as multifunctional ligands for the therapy of neurodegenerative diseases.

We describe the development of quinolylnitrones (QNs) as multifunctional ligands inhibiting cholinesterases (ChEs: acetylcholinesterase and butyrylcholinesterase-hBChE) and monoamine oxidases (hMAO-A/B) for the therapy of neurodegenerative diseases. We identified QN , a simple, low molecular weight nitrone, that is readily synthesized from commercially available 8-hydroxyquinoline-2-carbaldehyde. Quinolylnitrone has no typical pharmacophoric element to suggest ChE or MAO inhibition, yet unexpectedly showed potent inhibition of hBChE (IC = 1.

Applicability of RPMI 2650 and Calu-3 Cell Models for Evaluation of Nasal Formulations.

The RPMI 2650 and Calu-3 cell lines have been previously evaluated as models of the nasal and airway epithelial barrier, and they have demonstrated the potential to be used in drug permeation studies. However, limited data exist on the utilization of these two cell models for the assessment of nasal formulations. In our study, we tested these cell lines for the evaluation of in vitro permeation of intranasally administered drugs having a local and systemic effect from different solution- and suspension-based formulations to observe how the effects of formulations reflect on the measured in vitro drug permeability.

Indoles and 1-(3-(benzyloxy)benzyl)piperazines: Reversible and selective monoamine oxidase B inhibitors identified by screening an in-house compound library.

The therapeutic indications for monoamine oxidases A and B (MAO-A and MAO-B) inhibitors that have emerged from biological studies on animal and cellular models of neurological and oncological diseases have focused drug discovery projects upon identifying reversible MAO inhibitors. Screening of our in-house academic compound library identified two hit compounds that inhibit MAO-B with IC values in micromolar range. Two series of indole (23 analogues) and 3-(benzyloxy)benzyl)piperazine (16 analogues) MAO-B inhibitors were derived from hits, and screened for their structure-activity relationships.

Multitarget 2'-hydroxychalcones as potential drugs for the treatment of neurodegenerative disorders and their comorbidities.

The complex nature of neurodegenerative diseases (NDDs), such as Alzheimer's disease (AD) and Parkinson's disease (PD) calls for multidirectional treatment. Restoring neurotransmitter levels by combined inhibition of cholinesterases (ChEs) and monoamine oxidases (MAOs, MAO-A and MAO-B), in conjunction with strategies to counteract amyloid β (Aβ) aggregation, may constitute a therapeutically strong multi-target approach for the treatment of NDDs. Chalcones are a subgroup of flavonoids with a broad spectrum of biological activity.

Treatment of canine cognitive dysfunction with novel butyrylcholinesterase inhibitor.

Canine cognitive dysfunction (CCD) is common in aged dogs and has many similarities with Alzheimer's disease. Unfortunately, like Alzheimer's disease, CCD cannot be cured. In the present study, we treated dogs with CCD with our newly developed and characterized butyrylcholinesterase inhibitor (BChEi).

A Fine-Tuned Lipophilicity/Hydrophilicity Ratio Governs Antibacterial Potency and Selectivity of Bifurcated Halogen Bond-Forming NBTIs.

Herein, we report the design of a focused library of novel bacterial topoisomerase inhibitors (NBTIs) based on innovative mainly monocyclic right-hand side fragments active against DNA gyrase and Topo IV. They exhibit a very potent and wide range of antibacterial activity, even against some of the most concerning hard-to-treat pathogens for which new antibacterials are urgently needed, as reported by the WHO and CDC. NBTIs enzyme activity and whole cell potency seems to depend on the fine-tuned lipophilicity/hydrophilicity ratio that governs the permeability of those compounds through the bacterial membranes.

DC. Lipophilic Extract Patch for Skin Application: Preparation, In Vitro and In Vivo Studies.

Dodeca-2,4,8,10/-tetraenoic isobutylamide (tetraene) is the main component of DC. lipophilic extract, the bioavailability and immunomodulatory effect after oral administration in soft gel capsules in healthy volunteers of which we have already demonstrated. In the present work, we assessed the transdermal administration as an alternative route of administration of such an alkamide.

Suitability and functional characterization of two Calu-3 cell models for prediction of drug permeability across the airway epithelial barrier.

The Calu-3 cell line has been largely investigated as a physiological and pharmacological model of the airway epithelial barrier. Its suitability for prediction of drug permeability across the airway epithelia, however, has not been yet evaluated by using large enough set of model drugs. We evaluated two Calu-3 cell models (air-liquid and liquid-liquid) for drug permeability prediction based on the recent regulatory guidelines on showing suitability of in vitro permeability methods for drug permeability classification.

N-alkylpiperidine carbamates as potential anti-Alzheimer's agents.

Compounds capable of interacting with single or multiple targets involved in Alzheimer's disease (AD) pathogenesis are potential anti-Alzheimer's agents. In our aim to develop new anti-Alzheimer's agents, a series of 36 new N-alkylpiperidine carbamates was designed, synthesized and evaluated for the inhibition of cholinesterases [acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)] and monoamine oxidases [monoamine oxidase A (MAO-A and monoamine oxidase B (MAO-B)]. Four compounds are very promising: multiple AChE (IC = 7.

Biopharmaceutical classification of desloratadine - not all drugs are classified the easy way.

The biopharmaceutical classification of drugs was designed as a basis for bio-waivers - a mechanism with the double ethical benefit of delivering new drug formulations to the market with less human testing and lower cost. However, many drugs defy simple classification because in vitro permeability and stability assessment can be challenging as shown in this study for desloratadine. Literature shows that desloratadine is highly soluble, while data on luminal stability and permeability are circumstantial.

Stereoselective Activity of 1-Propargyl-4-styrylpiperidine-like Analogues That Can Discriminate between Monoamine Oxidase Isoforms A and B.

The resurgence of interest in monoamine oxidases (MAOs) has been fueled by recent correlations of this enzymatic activity with cardiovascular, neurological, and oncological disorders. This has promoted increased research into selective MAO-A and MAO-B inhibitors. Here, we shed light on how selective inhibition of MAO-A and MAO-B can be achieved by geometric isomers of and -1-propargyl-4-styrylpiperidines.

Suitability of RPMI 2650 cell models for nasal drug permeability prediction.

The RPMI 2650 cell line has been a subject of evaluation as a physiological and pharmacological model of the nasal epithelial barrier. However, its suitability for drug permeability assays has not yet been established on a sufficiently large set of model drugs. We investigated two RPMI 2650 cell models (air-liquid and liquid-liquid) for nasal drug permeability determination by adopting the most recent regulatory guidelines on showing suitability of in vitro permeability methods for drug permeability classification.

A review of methods for solubility determination in biopharmaceutical drug characterization.

The significance of thermodynamic solubility in biopharmaceutical compound or drug characterization as well as the importance of having methods that accurately establish it have been extensively addressed. Nonetheless, its precise determination continues to remain a challenging task to accomplish. Even more so when the number of compounds to evaluate is high and the available amount of each compound is low, both of which are inevitable for the compound characterization during the drug development process.

PBPK Absorption Modeling of Food Effect and Bioequivalence in Fed State for Two Formulations with Crystalline and Amorphous Forms of BCS 2 Class Drug in Generic Drug Development.

Prediction of the effect of food on drug's pharmacokinetics using modeling and simulation could cause difficulties due to complex in vivo processes. A generic formulation with amorphous form of BCS 2 class drug substance was developed and compared in vitro and in vivo to the reference drug product with drug substance in crystalline form. In order to approve generic formulation, some regulatory agencies are requesting to perform bioequivalence (BE) studies also in fed state.

Multi-target-directed ligands for treating Alzheimer's disease: Butyrylcholinesterase inhibitors displaying antioxidant and neuroprotective activities.

The limited clinical efficacy of current symptomatic treatment and minute effect on progression of Alzheimer's disease has shifted the research focus from single targets towards multi-target-directed ligands. Here, a potent selective inhibitor of human butyrylcholinesterase was used as the starting point to develop a new series of multifunctional ligands. A focused library of derivatives was designed and synthesised that showed both butyrylcholinesterase inhibition and good antioxidant activity as determined by the DPPH assay.

Identification and characterization of the novel reversible and selective cathepsin X inhibitors.

Cathepsin X is a cysteine peptidase involved in the progression of cancer and neurodegenerative diseases. Targeting this enzyme with selective inhibitors opens a new possibility for intervention in several therapeutic areas. In this study triazole-based reversible and selective inhibitors of cathepsin X have been identified.

Decreasing acidity in a series of aldose reductase inhibitors: 2-Fluoro-4-(1H-pyrrol-1-yl)phenol as a scaffold for improved membrane permeation.

Targeting long-term diabetic complications, as well as inflammatory pathologies, aldose reductase inhibitors (ARIs) have been gaining attention over the years. In the present work, in order to address the poor membrane permeation of previously reported ARIs, derivatives of N-phenylpyrrole, bearing groups with putative pKa≥7.4, were synthesized and evaluated for aldose reductase inhibitory activity.

Absorption and elimination of imatinib through the rat intestine in vitro.

Imatinib is a potent selective inhibitor of tyrosine kinases and is used primarily in the treatment of chronic myeloid leukemia and the gastrointestinal stromal tumour. Although, it is well established that imatinib is a substrate of several transport proteins which are also active in the intestinal mucosa, the mechanisms of imatinib intestinal absorption and elimination were not systematically investigated yet. To do that, we used a Sweetana-Grass type of diffusion chambers with segments of rat intestine as a model of the intestinal mucosa, measured the permeability coefficients of imatinib and its major metabolite (N-desmethyl imatinib) in both directions with and without specific and general inhibition of active transport, and calculated the efflux ratios.

The effect of lipid composition and liposome size on the release properties of liposomes-in-hydrogel.

To study the release of liposome-associated drugs into hydrogels, we designed and synthesized two pH-sensitive rhodamine derivatives to use as model compounds of different lipophilicities. The dyes were fluorescent when in the free form released from liposomes into the chitosan hydrogel, but not when incorporated within liposomes. The effect of liposomal composition, surface charge and vesicle size on the release of those incorporated dyes was evaluated.

Monitoring of imatinib targeted delivery in human leukocytes.

The success of imatinib therapy in chronic myeloid leukemia is highly influenced by its active transport into target cells. However, the methodology for analytical evaluation of intracellular drug concentration is rare and usually reliant upon the use of radioactively labeled drugs. More specifically, there is no published method available in the literature for the determination of imatinib concentration in granulocytes.

Correlative study of functional and structural regeneration of urothelium after chitosan-induced injury.

High transepithelial electrical resistance (TEER) demonstrates a functional permeability barrier of the normal urothelium, which is maintained by a layer of highly differentiated superficial cells. When the barrier is challenged, a quick regeneration is induced. We used side-by-side diffusion chambers as an ex vivo system to determine the time course of functional and structural urothelial regeneration after chitosan-induced injury.