Drug Repurposing by Simulating Flow Through Protein-Protein Interaction Networks.

As drug development is extremely expensive, the identification of novel indications for in-market drugs is financially attractive. Multiple algorithms are used to support such drug repurposing, but highly reliable methods combining simulation of intracellular networks and machine learning are currently not available. We developed an algorithm that simulates drug effects on the flow of information through protein-protein interaction networks, and used support vector machine to identify potentially effective drugs in our model disease, psoriasis. Using this method, we screened about 1,500 marketed and investigational substances, identified 51 drugs that were potentially effective, and selected three of them for experimental confirmation. All drugs inhibited tumor necrosis factor alpha-induced nuclear factor kappa B activity in vitro, suggesting they might be effective for treating psoriasis in humans. Additionally, these drugs significantly inhibited imiquimod-induced ear thickening and inflammation in the mouse model of the disease. All results suggest high prediction performance for the algorithm.

Sebum lipids influence macrophage polarization and activation.

BACKGROUND: As lipids are known to regulate macrophage functions, it is reasonable to suppose that a sebocyte-macrophage axis mediated by sebum lipids may exist. OBJECTIVES: To investigate if sebocytes could contribute to the differentiation, polarization and function of macrophages with their secreted lipids. METHODS: Oil Red O lipid staining and Raman spectroscopy were used to assess the dermal lipid content and penetration. Immunohistochemistry was used to analyse the macrophage subsets. Human peripheral blood monocytes were differentiated in the presence of either supernatant from human SZ95 sebocytes or major sebum lipid components and activated with Propionibacterium acnes. Macrophage surface markers and their capacity to uptake fluorescein isothiocyanate-conjugated P. acnes were detected by fluorescence-activated cell sorting measurements. Cytokine protein levels were evaluated by enzyme-linked immunosorbent assay and Western blot analysis. RESULTS: Sebaceous gland-rich skin had an increased dermal lipid content vs. sebaceous gland-poor skin to which all the tested sebum component lipids could contribute by penetrating the dermoepidermal barrier. Of the lipids, oleic acid and linoleic acid promoted monocyte differentiation into alternatively activated macrophages. Moreover, linoleic acid also had an anti-inflammatory effect in P. acnes-activated macrophages, inhibiting the secretion of interleukin (IL)-1ß, IL-6 and tumour necrosis factor (TNF)-α. Squalene, palmitic acid, stearic acid and oleic acid augmented the secretion of IL-1ß, even in the absence of P. acnes, whereas oleic acid had a selective effect of inducing IL-1ß but downregulating IL-6 and TNF-α secretion. CONCLUSIONS: Our results suggest a role for sebaceous glands in modulating innate immune responses via their secreted lipids that are of possible pathological and therapeutic relevance.

In vitro skin models in the optimization of skin formulations.

BACKGROUND: Transdermal drug delivery is assumed to have a growing importance in drug development recently, thus it is crucial to optimize the penetration properties of drug into through the skin. Most of the current developments rely on the use of appropriate ex vivo animal or artificial models. However, the limited availability of human skin and the increasing restrictions in connection with animal testing encouraged the searchfor suitable artificial skin models. METHOD: For the review, we have searched the databases of scientific and medical research to collect the available publications about the in vitro skin models. Furthermore, we overviewed the methods of the DataBase service on ALternative Methods to animal experimentation (DB-ALM) database and the guidelines of Organisation for Economic Co-operation and Development (OECD). RESULTS: In vitro skin models have advantages like reproducibility, relatively low cost, easy storage, uncomplicated handling, and they offer a possibility for rapid screening and faster optimization of skin formulations. Furthermore, their composition can be easily modified which allows studying the relationship between certain pathological conditions and barrier function. However, the limitations of these models are needed to be taken into account. CONCLUSION: This review attempts to provide an overview of the most frequently used models, focusing on their limitations and advantages. Accessibility, easiness of the application, cost and the respective limitations have to be considered in order to choose the most appropriate in vitro model for the particular objective.

Development of nanostructured lipid carriers containing salicyclic acid for dermal use based on the Quality by Design method.

The aim of our present work was to evaluate the applicability of the Quality by Design (QbD) methodology in the development and optimalization of nanostructured lipid carriers containing salicyclic acid (NLC SA). Within the Quality by Design methology, special emphasis is layed on the adaptation of the initial risk assessment step in order to properly identify the critical material attributes and critical process parameters in formulation development. NLC SA products were formulated by the ultrasonication method using Compritol 888 ATO as solid lipid, Miglyol 812 as liquid lipid and Cremophor RH 60® as surfactant. LeanQbD Software and StatSoft. Inc. Statistica for Windows 11 were employed to indentify the risks. Three highly critical quality attributes (CQAs) for NLC SA were identified, namely particle size, particle size distribution and aggregation. Five attributes of medium influence were identified, including dissolution rate, dissolution efficiency, pH, lipid solubility of the active pharmaceutical ingredient (API) and entrapment efficiency. Three critical material attributes (CMA) and critical process parameters (CPP) were identified: surfactant concentration, solid lipid/liquid lipid ratio and ultrasonication time. The CMAs and CPPs are considered as independent variables and the CQAs are defined as dependent variables. The 23 factorial design was used to evaluate the role of the independent and dependent variables. Based on our experiments, an optimal formulation can be obtained when the surfactant concentration is set to 5%, the solid lipid/liquid lipid ratio is 7:3 and ultrasonication time is 20min. The optimal NLC SA showed narrow size distribution (0.857±0.014) with a mean particle size of 114±2.64nm. The NLC SA product showed a significantly higher in vitro drug release compared to the micro-particle reference preparation containing salicylic acid (MP SA).

Anti-irritant and anti-inflammatory effects of glycerol and xylitol in sodium lauryl sulphate-induced acute irritation.

BACKGROUND: Glycerol is known to possess anti-irritant and hydrating properties and previous studies suggested that xylitol may also have similar effects. OBJECTIVE: Our aim was to study whether different concentrations of these polyols restore skin barrier function and soothe inflammation in sodium lauryl sulphate (SLS)-induced acute irritation. METHODS: The experiments were performed on male SKH-1 hairless mice. The skin of the dorsal region was exposed to SLS (5%) for 3 h alone or together with 5% or 10% of glycerol respectively. Further two groups received xylitol solutions (8.26% and 16.52% respectively) using the same osmolarities, which were equivalent to those of the glycerol treatments. The control group was treated with purified water. Transepidermal water loss (TEWL) and skin hydration were determined. Microcirculatory parameters of inflammation were observed by means of intravital videomicroscopy (IVM). Furthermore, accumulation of neutrophil granulocytes and lymphocytes, the expression of inflammatory cytokines and SLS penetration were assessed, as well. RESULTS: Treatment with the 10% of glycerol and both concentrations of xylitol inhibited the SLS-induced elevation of TEWL and moderated the irritant-induced increase in dermal blood flow and in the number of leucocyte-endothelial interactions. All concentrations of the applied polyols improved hydration and prevented the accumulation of lymphocytes near the treatment site. At the mRNA level, neither glycerol nor xylitol influenced the expression of interleukin-1 alpha. However, expression of interleukin-1 beta was significantly decreased by the 10% glycerol treatment, while expression of tumour necrosis factor-alpha decreased upon the same treatment, as well as in response to xylitol. Higher polyol treatments decreased the SLS penetration to the deeper layers of the stratum corneum. CONCLUSION: Both of the analysed polyols exert considerable anti-irritant and anti-inflammatory properties, but the effective concentration of xylitol is lower than that of glycerol.

How chromophore shape determines the spectroscopy of phenylene-vinylenes: origin of spectral broadening in the absence of aggregation.

Single oligo(phenylene-vinylene) molecules constitute model systems of chromophores in disordered conjugated polymers and can elucidate how the actual conformation of an individual chromophore, rather than that of an overall polymer chain, controls its photophysics. Single oligomers and polymer chains display the same range of spectral properties. Even heptamers support pi-electron conjugation across approximately 80 degrees curvature, as revealed by the polarization anisotropy in excitation and supported by quantum chemical calculations. As the chain becomes more deformed, the spectral linewidth at low temperatures, often interpreted as a sign of aggregation, increases up to 30-fold due to a reduction in photophysical stability of the molecule and an increase in random spectral fluctuations. The conclusions aid the interpretation of results from single-chain Stark spectroscopy in which large static dipoles were only observed in the case of narrow transition lines. These narrow transitions originate from extended chromophores in which the dipoles induced by backbone substituents do not cancel out. Chromophores in conjugated polymers are often thought of as individual linear transition dipoles, the sum of which make up the polymer's optical properties. Our results demonstrate that, at least for phenylene-vinylenes, it is the actual shape of the individual chromophore rather than the overall chromophoric arrangement and form of the polymer chain that dominates the spectroscopic properties.

Lyotropic liquid crystal preconcentrates for the treatment of periodontal disease.

The aim of our study was to develop water-free lyotropic liquid crystalline preconcentrates, which consist of oils and surfactants with good physiological tolerance and spontaneously form lyotropic liquid crystalline phase in aqueous environment. In this way these preconcentrates having low viscosity can be injected into the periodontal pocket, where they are transformed into highly viscous liquid crystalline phase, so that the preparation is prevented from flowing out of the pocket due to its great viscosity, while drug release is controlled by the liquid crystalline texture. In order to follow the structure alteration upon water absorption polarization microscopical and rheological examinations were performed. The water absorption mechanism of the samples was examined by the Enslin-method. Metronidazole-benzoate was used as active agent the release of which was characterized via in vitro investigations performed by means of modified Kirby-Bauer disk diffusion method. On the grounds of the results it can be stated that the 4:1 mixture of the investigated surfactants (Cremophor EL, Cremophor RH40) and oil (Miglyol 810) formed lyotopic liquid crystalline phases upon water addition. Polarization microscopic examinations showed that samples with 10-40% water content possessed anisotropic properties. On the basis of water absorption, rheological and drug release studies it can be concluded that the amount of absorbed water and stiffness of lyotropic structure influenced by the chemical entity of the surfactant exerted major effect on the drug release.

Evaluation of ketamine systemic absorption from topical preparations. Short Communication.

The aim of this study was to evaluate the systemic absorption of the topically administered ketamine using different vehicles and additives, in order to develop a transdermal therapeutic system (TTS) of this drug. After the application of different ketamine preparations (1% in hydrogel, o/w cream, or organogel) the ketamine appeared in the blood. The lowest level could be observed with o/w cream, while the highest concentration was achieved by means of the hydrogel system, however this difference was not significant. Further studies are going to be performed with higher drug concentrations for the characterization of the differences in the pharmacodynamics of the drug with different vehicles and to evaluate the correlation between the in vitro and in vivo absorption.

In vitro and in vivo percutaneous absorption of topical dosage forms: case studies.

This article evaluated the influence of vehicle compositions on topical drug availability. In vitro drug release and in vivo experiments were performed in case of the hydrophilic ketamine hydrochloride and the lipophilic piroxicam. Ketamine hydrochloride is a NMDA receptor antagonist that has been useful for anesthesia and analgesia. The study of transdermal ketamine delivery is a novelty, because nobody has investigated the hypnotic effects of ketamine after this administration route. In vitro measurements gave a good basis for screening among the developed products. The physiological changes after ketamine administration showed, that there were significant differences among the parameters tested (breathing rate, duration of sleep) from the developed products (hydrogel, lyotropic liquid crystal and o/w cream) compared to the reference product (Carbopol gel). The in vivo feedback for piroxicam was the measurement of the anti-inflammatory activity by edema inhibition percentage. Significant differences were measured in case of the developed systems compared to the reference.

Structure and drug release of lamellar liquid crystals containing glycerol.

Lamellar lyotropic liquid crystalline (LLC) systems are thermodynamically stable, optically isotropic systems, which are formed with low energy input. New possibilities for the development of controlled drug delivery systems are inherent in these systems due to their stability and special skin-similarly structure. The present aim was to formulate multicomponent LLC systems with a relatively low surfactant content, composed of materials official in the European Pharmacopoeia 4th. Polarizing light microscopic examination of the samples was carried out, together with TEM observation of replicas produced by freeze-fractured technique for the purpose of demonstrating the presence of lamellar LC domains. Our LLC samples contained: Brij 96 (poly-oxyethylene-10-oleyl ether) with water, liquid petrolatum (LP) and glycerol in a given concentration range. The interlamellar repeated distance (d(L)) confirming the existence of a regular structure was determined by means of X-ray diffraction. The d(L) and G'values of the samples changed according to a maximum curve with increasing glycerol concentration up to 40% (w/w). A prolonged drug release was observed in case of the very water-soluble ephedrine hydrochloride and the same phenomena was observed in the case of tenoxicam, which is practically insoluble in water.

[Investigation of ambiphilic creams. II. Structural stability]. / Ambifil krémek vizsgálata. II. A szerkezet stabilitásának tanulmányozása.

Ambiphile creams containing white petrolatum, cetylstearyl-alcohol, Emulgator BTO and distilled water were investigated. The elements of the study of structure-stability were as follows: evaporation of water-phase, mechanical stability of structure and its heatstability. A multiplicative function was found between the loss of mass of creams and the evaporation time. The viscosity vs. temperature function is a two-steps process, it can be divided to a section before melting and an other section after it. Decreasing viscosity under shearing time can be characterized by a logarithmic equation.

[Factors influencing liberation of drug from semisolid dosage forms]. / Félszilárd gyógyszerformák gyógyszerleadását befolyásoló tényezök.

Liberation of salicylic acid--as a model active agent--was investigated from white petrolatum, creams w/o and o/w types and hydrogels. Active agent was applied in suspended, dissolved forms, in inclusion complexes and solubilized state. The process of liberation was studied by a continuous through-flow method, with Hanson vertical diffusion cell. The results of experiments were evaluated by factorial design method. Increase of the concentration of salicylic acid, polarity of vehicle and solubilized state of drug increased the drug release. It was established that the partitioning released drug was the most important step of drug release. Factors changing partitioning influenced the liberation to the highest degree.

[Liberation of active agents from coherent emulsions]. / Hatóanyag felszabadulása koherens emulziókból.

Drug release from coherent emulsions containing high water concentration (50-80 w/w%) was studied. Composition of coherent systems was as follows: self-emulsifying wax and preserved water. Griseofulvin was applied as active agent in suspended form. The liberation experiments were carried out with Hanson vertical diffusion cell, acceptor phase was distilled water, membrane was celophane one. It was established that the time course of liberation of griseofulvin from coherent emulsions can be characterized with a multiplicative function and the exponent of this function is about 0.5. The quantity of released drug increased linearly with the water content and it decreased exponentially with the viscosity of coherent emulsions.

[Ampiphilic creams. 1. study of formation and consistency]. / Ambifil krémek vizsgálata 1. A képzõdés és a konzisztencia tanulmányozása.

Ambiphilic type creams were prepared and their consistency was investigated by rheological method. It was established, that a surfactant named Emulgator BTO formed ambifilic character in the case of given portion of oil- and water phases. The type of ambiphilic creams and the values of structural viscosity were changed after the dilution with water or oil.

[Influence of viscosity on drug release from ointments, creams, gels and emulsions]. / A viszkozitás hatása kenöcsök, krémek, gélek és emulziók gyógyszerleadására.

The authors studied the drug release from high number of water-free ointments, creams, emulsions and hydrogels. They targeted to find correlation between the viscosity of these pharmaceutical forms and their drug release. Neutral oil was the lipophilic phase of emulsions, the emulsifiers were from Tween and Tagat series. The creams tested consisted of ESMA ointment, Teginacid and/or Softisan emulsifiers and water in 60-80 w/w%. The drug release from Eudispert, methyl-cellulose and hydroxy-ethylcellulose gels was studied. The applied active ingredients were as follows: griseofulvin, sulfadimidine, salicylic acid and ephedrine hydrochloride. Relevant literature suggest a reciprocal correlation between the viscosity of ointments and the quantity of the released drugs. The authors confirmed the general validity of this correlation in case of the following preconditions: if the solubility and distribution of drug do not change along with the change of viscosity there is reciprocal ratio between viscosity and the quantity of drug released. This reciprocal correlation prevails only in a small range of viscosity, that is in systems resembling Newton's liquids. In cases of ointments and gels of higher viscosity a reciprocal relationship exists between the logarithm of viscosity and the quantity of drugs released.