PRICE AND NON-PRICE COMPETITIVENESS FACTORS AND ECONOMIC DEVELOPMENT. A PVAR APPROACH

The present study aims at identifying the link between economic growth and a wide variety of external competitiveness indicators, related to both price and non-price factors. Using data for European Union, we estimate a series of panel Vector Autoregression (PVAR) models and find that non-price indicators have a higher contribution in explaining GDP developments compared to traditional price and cost based measures of competitiveness. On the other hand, the results underline the broadness of competitiveness concept, as economic growth alone is found not to determine significant effects on the competitive capacity of economies

PRICE AND NON-PRICE COMPETITIVENESS FACTORS AND ECONOMIC DEVELOPMENT. A PVAR APPROACH

The present study aims at identifying the link between economic growth and a wide variety of external competitiveness indicators, related to both price and non-price factors. Using data for European Union, we estimate a series of panel Vector Autoregression (PVAR) models and find that non-price indicators have a higher contribution in explaining GDP developments compared to traditional price and cost based measures of competitiveness. On the other hand, the results underline the broadness of competitiveness concept, as economic growth alone is found not to determine significant effects on the competitive capacity of economies

Assessment of the impact of temperature on the viscosity of the combined ear drops

Introduction. In the development of ototopic formulations, physicochemical factors such as solubility, viscosity, tonicity, surfactant properties, preservatives, impregnation capacity, ceruminolytic and diffusion activity play a very important role. Thus, auricular drops may contain excipients to adjust viscosity, adjust or modify pH, increase solubility of active substances or stabilise the preparation. The viscosity of a topical formulation is important because of the effect it has on the ability to effectively release the active substances at the site of administration. Temperature is a key factor in maintaining the stability, bioavailability and efficacy of auricular drops. Temperature variations in the process of storage and use of the ototopical pharmaceutical form can influence its physical parameters. Aim of study. To study the influence of temperature on the viscosity values of combined isohydrofural and methyluracil ear drops. Methods and materials. The Fungilab Smart R rotary viscometer was used to investigate the viscosity. The viscosity of the droplets was determined at 10 rotational speeds at temperatures of 25 and 37°C. Results. Optimal viscosity ensures prolonged contact time with the ear surface and prevents droplet leakage. The choice of solvent in the process of ear drop development is reasoned by the type of treatment and application site. In the case of infection of the external auditory canal, the use of non-aqueous solvents is recommended. The investigated formulation contains PEG-400 and propylene glycol, the latter has advantages, being less hygroscopic and poorly oxidizable, retains preservative properties at 15% concentration. The viscosity of the auricular drops was evaluated at temperatures of 25°C (t. at storage) and 37°C (t. at the administration site). The viscosity values at shear rate 0.3 RPM were: at 25°C - 27.247 P⋅102; at 37°C - 25.151 P⋅102. By plotting the rheograms of the dependence of viscosity and shear stress on shear rate, the non-Newtonian and pseudoplastic character of the droplets was demonstrated (viscosity of liquids decreases with increasing shear rate). Conclusion. It was determined that at a concentration of 60% PEG-400 and 20% propylene glycol, the values of viscosity and shear stress at the lowest shear rate decrease with increasing temperature, but remain within acceptable limits to ensure optimal contact time with the ear surface

Dielectric elastomers based on silicones filled with transitional metal complexes

New composite dielectric elastomers with improved dielectric properties were prepared on the basis of polydimethylsiloxane rubber filled with new types of metal (Mn, Fe, Cr) complexes of the bis-azomethine derived from the condensation of a siloxane diamine, 1,3-bis(aminopropyl)tetramethyldisiloxane, with 3,5-di-bromo-2-hydroxybenzaldehyde. The tetramethyldisiloxane fragment from the structure of the complexes creates the premise for a good compatibility with the silicone matrix without the need for other surface treatments while the complexed metal unit through its polar character changes the dielectric properties of the material. The resulted composites crosslinked at room temperature as dielectric elastomer films were investigated in order to establish if such materials are suitable for use in the structure of electromechanical devices. The introduction of metal complexes in the polymer matrix has led to a slight decrease of the elastic domain but increased the relative dielectric permittivity with up to 100% and the electromechanical sensitivity of the materials, with negligeable changes of the thermal behavior and overall moisture sorption capacity, thus preserving the chemical stability and hydrophobic character of siloxanes

Dielectric silicone elastomers with mixed ceramic nanoparticles

A ceramic material consisting in a zirconium dioxide-lead zirconate mixture has been obtained by precipitation method, its composition being proved by wide angle X-ray powder diffraction and energy-dispersive X-ray spectroscopy. The average diameter of the ceramic particles ranged between 50 and 100 nm, as revealed by transmission electron microscopy images. These were surface treated and used as filler for a high molecular mass polydimethylsiloxane-α,ω-diol (Mn = 450,000) prepared in laboratory, the resulted composites being further processed as films and crosslinked. A condensation procedure, unusual for polydimethylsiloxane having such high molecular mass, with a trifunctional silane was approached for the crosslinking. The effect of filler content on electrical and mechanical properties of the resulted materials was studied and it was found that the dielectric permittivity of nanocomposites increased in line with the concentration of ceramic nanoparticles

Preparation of electromechanically active silicone composites and some evaluations of their suitability for biomedical applications

Some films based on electromechanically active polymer composites have been prepared. Polydimethylsiloxane-α,ω-diols (PDMSs) having different molecular masses (Mv = 60 700 and Mv = 44 200) were used as matrix in which two different active fillers were incorporated: titanium dioxide in situ generated from its titanium isopropoxide precursor and silica particles functionalized with polar aminopropyl groups on surface. A reference sample based on simple crosslinked PDMS was also prepared. The composites processed as films were investigated to evaluate their ability to act as efficient electromechanical actuators for potential biomedical application. Thus, the surface morphology of interest for electrodes compliance was analysed by atomic force microscopy. Mechanical and dielectric characteristics were evaluated by tensile tests and dielectric spectroscopy, respectively. Electromechanical actuation responses were measured by interferometry. The biocompatibility of the obtained materials has been verified through tests in vitro and, for valuable films, in vivo. The experimental, clinical and anatomopathological evaluation of the in vivo tested samples did not reveal significant pathological modifications

Interpenetrating poly(urethane-urea)–polydimethylsiloxane networks designed as active elements in electromechanical transducers

A poly(urethane-urea-siloxane) was prepared in a two-step procedure involving the synthesis of a bis-isocyanate prepolymer on the basis of 4,4′-diphenylmethane diisocyanate, a polyether glycol and dimethylol propionic acid, and its extension by reacting with 1,3-bis(3-aminopropyl)tetramethyldisiloxane. The resulted polymer was used in different percentages to prepare three series of interpenetrating networks (IPNs) with polydimethylsiloxane-α,ω-diols with molecular masses, Mn, of 70000, 230000 and 370000 g mol−1. A polydimethylsiloxane–polyethyleneoxide graft copolymer was added as a compatibilizing agent. The IPN precursors were mixed in solution and processed as films. During solvent evaporation, the chemical crosslinking of the polydimethylsiloxane-α,ω-diols occurs with tetraethyl orthosilicate in the presence of dibutyltin dilaurate, while in the case of poly(urethane-urea-siloxane) only physical crosslinking by hydrogen bonds is expected to occur. The morphology and thermal transitions of the resulted networks were examined by scanning electron microscopy, differential scanning calorimetry with dynamic mechanical analysis. The mechanical and dielectric characteristics (dielectric permittivity, loss, strength) of the aged films were studied. Their responsiveness to an external stimulus in the form of an increasing electric field was assessed by electromechanical measurements and expressed as lateral strain. The results were critically analyzed with respect to each other as a correlation with their composition and compared with those obtained for three common commercially available dielectric elastomers

Aplicarea difracției cu raze X în cercetarea compatibilității substanțelor active cu excipienții

Catedra de chimie farmaceutică şi toxicologică, USMF „Nicolae Testemiţanu”Background. Compatibility studies between active ingredients and excipients in a pharmaceutical form are a key step in the development of a new drug, being applied several methods to investigate potential transformations at the molecular level. Objective of the study. Evaluation of the possibilities of using X-ray diffraction in researching of the compatibility of active principles with excipients in pharmaceutical forms. Material and Methods. Advanced bibliographic study using the databases Medline, Environmental Issues & Policy Index, Environmental Sci & Pollution Mgmt, Scopus (Elsevier), Current Contents, Scirus. Over 120 bibliographic sources were evaluated. Results. An increasing number of studies have focused on the development of non-specific rapid methods for assessing compatibility at an early stage of the development process. In recent years, more and more studies attest to the use of X-ray diffraction techniques. In 88% of the evaluated sources, X-ray diffraction has been combined with spectral (FT-IR) and thermal (DSC) methods, being applied only for crystalline substances testing. At 24% of the evaluated articles, molecular interactions between active and auxiliary substances were reported. Some researchers (12% of sources) successfully apply Bragg's law in interpreting diffractograms. Conclusion. The identification of crystalline substances by X-ray diffraction with determining of the interplanar distance and the intensity of deviation from these X-ray planes is an advantageous method of detecting incompatibilities.Introducere. Studiile de compatibilitate dintre principiile active și excipienții dintr-o formă farmaceutică reprezintă o etapă cheie în procesul de elaborare-dezvoltare a unui nou medicament, fiind aplicate mai multe metode de investigare a potențialelor transformări la nivel molecular. Scopul lucrării. Evaluarea posibilităților de utilizare a difracției cu raze X în cercetarea compatibilității principiilor active cu excipienții în forme farmaceutice. Material și Metode. Studiu bibliografic avansat cu utilizarea bazelor de date Medline, Environmental Issues & Policy Index, Environmental Sci & Pollution Mgmt, Scopus (Elsevier), Current Contents, Scirus. Au fost evaluate peste 120 de surse bibliografice. Rezultate. Un număr tot mai mare de studii s-au axat pe dezvoltarea unor metode rapide nespecifice pentru evaluarea compatibilităţii într-un stadiu cât mai timpuriu al procesului de dezvoltare. În ultimii ani tot mai multe studii atestă utilizarea tehnicilor de difracție cu raze X. În 88% din sursele evaluate, difracția cu raze X a fost combinată cu metodele spectrale (FT-IR) și termice (DSC), fiind aplicată doar pentru testarea substanțelor cristaline. În 24% din articolele evaluate au fost semnalate interacțiuni la nivel molecular dintre substanțe active și auxiliare. Unii cercetători (12% din surse) aplică cu success legea lui Bragg în interpretarea difractogramelor. Concluzii. Identificarea substanțelor cristaline prin difracție cu raze X cu determinarea distanței interplanare și a intensității de deviere de la aceste planuri de raze X constituie o metodă avantajoasă de detectare a incompatibilităților

Aplicarea cromatografiei pe strat subțire în studiile de degradare accelerată a picăturilor auriculare combinate

Background. The TLC method is successfully used in stability studies; it is accessible and ensures the identification of possible degradation products, being particularly useful for testing of combined pharmaceutical formulations. Objective of the study. Study of the accelerated degradation process of combined eardrops with Isohydrofural (IHF) and Methyluracil (MU) by TLC. Material and Methods. Experimental ear drops subjected to accelerated degradation; chromatographic chamber; mobile phases: chloroform-acetone (70:30), 1-butanol-diethyl-ether-acetone (10: 85:5), ethylacetate-hexane (2:1), glacial acetic acid-water-butanol (1:1:4), chloroform-methanol-glacial acetic acid (90:8:8), chloroform-methanol-glacial acetic acid (95:10:2); UV lamp; developing reagents. Results. Chromatography results showed that only the mobile phase ethyl acetate-hexane (2:1) provides the possibility of simultaneous detection of both substances, which is used in the qualitative analysis of the compounds in the mechanical mixture and pharmaceutical form in the accelerated degradation process (thermal, oxidative, hydrolytic and UV stress conditions). Degradation products of IHF (Rf = 0.24) and MU (Rf = 0.51) were determined following oxidation and exposure to temperature. The Rf values of the substances in the mechanical mixture and pharmaceutical form were close (0.37 for IHF and 0.72 for MU). Conclusion. The technique developed for the TLC determinations ensures separation of components in the combination and detection of degradation products.Study conducted with the support of the project 20.80009.8007.14 “Complex researches for the elaboration of new local anti-infectious pharmaceutical products for the optimization of pharmacotherapy of dental, oropharyngeal and auricular diseases”, within the State Program (2020-2023), project leader: Valica Vladimir, PhD, univ, prof., contracting authority: National Agency for Research and Development.Introducere. Metoda CSS este utilizată cu succes în studiile de stabilitate, este accesibilă și asigură identificarea eventualelor produse de degradare, fiind utilă în special pentru testarea produsele farmaceutice combinate. Scopul lucrării. Studiul procesului de degradare accelerată ale picăturilor auriculare combinate cu izohidrafural (IHF) și metiluracil (MU) prin CSS. Material și Metode. Picături auriculare preparate în laborator și supuse degradării accelerate; cameră cromatografică; faze mobile: cloroform-acetonă (70:30), 1-butanol-eter dietilic-acetonă (10:85:5), etilacetat-hexan (2:1), acid acetic glacial-apă-butanol (1:1:4), cloroform-metanol- acid acetic glacial (90:8:8), cloroform-metanol-acid acetic glacial (95:10:2); lampă UV; reagenți de revelare. Rezultate. Rezultatele cromatografierii au demonstrat, că numai faza mobilă etilacetat-hexan (2:1) asigură posibilitatea detectării concomitente a ambelor substanțe, aceasta fiind utilizată în analiza calitativă a compușilor din amestec mecanic și forma farmaceutică în procesul degradării accelerate (condiții de stress termic, oxidativ, hidrolitic și raze UV). S-au determinat produse de degradare ale IHF (Rf = 0,24) și ale MU (Rf = 0,51) în urma oxidării și expunerii la temperatură. Valorile Rf-ului substanțelor din amestec mecanic și formă farmaceutică au fost apropiate (0,37 pentru IHF și 0,72 pentru MU). Concluzii. Tehnica de lucru elaborată pentru determinările CSS asigură separarea componentelor din combinație și detectarea produselor de degradare.Studiu realizat cu suportul proiectului 20.80009.8007.14 „Cercetări complexe de elaborare a noilor produse farmaceutice antiinfecțioase autohtone pentru optimizarea farmacoterapiei afecțiunilor stomatologice, orofaringiene și auriculare”, din cadrul Programului de Stat (2020-2023), conducător de proiect: Valica Vladimir, dr. hab. șt. farm., prof. univ., autoritatea contractantă: Agenția Națională pentru Cercetare și Dezvoltare

Application of thin-layer chromatography in accelerated degradation studies of combined eardrops

Universitatea de Stat de Medicină şi Farmacie „Nicolae Testemiţanu”, Chişinău, Republica MoldovaStudy conducted with the support of the project 20.80009.8007.14 “Complex researches for the elaboration of new local anti-infectious pharmaceutical products for the optimization of pharmacotherapy of dental, oropharyngeal and auricular diseases”, within the State Program (2020-2023), project leader: Valica Vladimir, PhD, univ, prof., contracting authority: National Agency for Research and Development.Studiu realizat cu suportul proiectului 20.80009.8007.14 „Cercetări complexe de elaborare a noilor produse farmaceutice antiinfecțioase autohtone pentru optimizarea farmacoterapiei afecțiunilor stomatologice, orofaringiene și auriculare”, din cadrul Programului de Stat (2020-2023), conducător de proiect: Valica Vladimir, dr. hab. șt. farm., prof. univ., autoritatea contractantă: Agenția Națională pentru Cercetare și Dezvoltare.Introducere. Metoda CSS este utilizată cu succes în studiile de stabilitate, este accesibilă și asigură identificarea eventualelor produse de degradare, fiind utilă în special pentru testarea produsele farmaceutice combinate. Scopul lucrării. Studiul procesului de degradare accelerată ale picăturilor auriculare combinate cu izohidrafural (IHF) și metiluracil (MU) prin CSS. Material și Metode. Picături auriculare preparate în laborator și supuse degradării accelerate; cameră cromatografică; faze mobile: cloroform-acetonă (70:30), 1-butanol-eter dietilic-acetonă (10:85:5), etilacetat-hexan (2:1), acid acetic glacial-apă-butanol (1:1:4), cloroform-metanol-acid acetic glacial (90:8:8), cloroform-metanol-acid acetic glacial (95:10:2); lampă UV; reagenți de revelare. Rezultate. Rezultatele cromatografierii au demonstrat, că numai faza mobilă etilacetat-hexan (2:1) asigură posibilitatea detectării concomitente a ambelor substanțe, aceasta fiind utilizată în analiza calitativă a compușilor din amestec mecanic și forma farmaceutică în procesul degradării accelerate (condiții de stress termic, oxidativ, hidrolitic și raze UV). S-au determinat produse de degradare ale IHF (Rf = 0,24) și ale MU (Rf = 0,51) în urma oxidării și expunerii la temperatură. Valorile Rf-ului substanțelor din amestec mecanic și formă farmaceutică au fost apropiate (0,37 pentru IHF și 0,72 pentru MU). Concluzii. Tehnica de lucru elaborată pentru determinările CSS asigură separarea componentelor din combinație și detectarea produselor de degradare.Background. The TLC method is successfully used in stability studies; it is accessible and ensures the identification of possible degradation products, being particularly useful for testing of combined pharmaceutical formulations. Objective of the study. Study of the accelerated degradation process of combined eardrops with Isohydrofural (IHF) and Methyluracil (MU) by TLC. Material and Methods. Experimental ear drops subjected to accelerated degradation; chromatographic chamber; mobile phases: chloroform-acetone (70:30), 1-butanol-diethyl-ether-acetone (10: 85:5), ethylacetate-hexane (2:1), glacial acetic acid-water-butanol (1:1:4), chloroform-methanol-glacial acetic acid (90:8:8), chloroform-methanol-glacial acetic acid (95:10:2); UV lamp; developing reagents. Results. Chromatography results showed that only the mobile phase ethyl acetate-hexane (2:1) provides the possibility of simultaneous detection of both substances, which is used in the qualitative analysis of the compounds in the mechanical mixture and pharmaceutical form in the accelerated degradation process (thermal, oxidative, hydrolytic and UV stress conditions). Degradation products of IHF (Rf = 0.24) and MU (Rf = 0.51) were determined following oxidation and exposure to temperature. The Rf values of the substances in the mechanical mixture and pharmaceutical form were close (0.37 for IHF and 0.72 for MU). Conclusion. The technique developed for the TLC determinations ensures separation of components in the combination and detection of degradation products