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1.
Molecules ; 29(10)2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38792213

RESUMEN

The aim of the work was to determine important parameters of the course of π-A isotherms, which can determine the HLB (hydrophilic-lipophilic balance) value of surfactant mixtures with selected structural features, such as a straight or branched hydrocarbon chain and a double bond, using RSM (response surface methodology) computational methods. Mixtures of surfactants derived from fatty acids and sorbitan with specific HLB values were evaluated by Langmuir trough. The resulting elasticity modules (ELM) and molecules surfaces (SAM) were evaluated via response surface methodology and respective equations were calculated. The π-A isotherm determined in a Langmuir trough and the ELM and SAM parameters determined on the basis of this isotherm may be useful for determining the HLB of a fixed surfactant mixture. The RSM method used, in which ELM and SAM were assumed as two independent variables, can be a useful technique for tracking the influence of individual molecular characteristics on the hydrophilic-lipophilic properties of mixtures of surfactant compounds. Changes in HLB as a dependent variable can be described as a function of ELM and SAM.

2.
Int J Mol Sci ; 24(3)2023 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-36768998

RESUMEN

Due to its high instability and rapid degradation under adverse conditions, tetracycline hydrochloride (TC) can cause difficulties in the development of an effective but stable formulation for the topical treatment of acne. The aim of the following work was to propose a hydrogel formulation that would ensure the stability of the antibiotic contained in it. Additionally, an important property of the prepared formulations was the activity of the alcoholamines contained in them against the components of the model sebum. This feature may help effectively cleanse the hair follicles in the accumulated sebum layer. A series of formulations with varying proportions of anionic polymer and alcoholamine and containing different polymers have been developed. The stability of tetracycline hydrochloride contained in the hydrogels was evaluated for 28 days by HPLC analysis. Formulations containing a large excess of TRIS alcoholamine led to the rapid degradation of TC from an initial concentration of about 10 µg/mL to about 1 µg/mL after 28 days. At the same time, these formulations showed the highest activity against artificial sebum components. Thanks to appropriately selected proportions of the components, it was possible to develop a formulation that assured the stability of tetracycline for ca. one month, while maintaining formulation activity against the components of model sebum.


Asunto(s)
Sebo , Tetraciclina , Tetraciclina/farmacología , Tetraciclina/metabolismo , Sebo/química , Sebo/metabolismo , Hidrogeles/metabolismo , Antibacterianos/metabolismo , Piel , Polímeros/metabolismo
3.
Int J Mol Sci ; 24(6)2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36982680

RESUMEN

The properties of sodium hyaluronate (HA), such as hygroscopicity, flexibility, the ability to form hydrogels, as well as biocompatibility and biodegradability, are beneficial for the applications in pharmaceutical technology, cosmetics industry, and aesthetic medicine. The aim of this study was to prepare HA-based hydrogels doped with active pharmaceutical ingredient (API): a cationic drug-lidocaine hydrochloride or anionic drug-sodium. The interaction between the carrier and the implemented active pharmaceutical substances was evaluated in prepared systems by applying viscometric measurements, performing release tests of the drug from the obtained formulations, and carrying out FTIR and DSC. The data from release studies were analyzed using the zero-, first-, and second-order kinetics and Higuchi, Korsmeyer-Peppas, and Hixon-Crowell models. The respective kinetic parameters: the release rate constants, the half-release time and, in the case of the Korsmeyer-Peppas equation, the n parameter were calculated. The variability between the obtained release profiles was studied by calculating the difference (f1) and the similarity factor (f2) as well as employing statistical methods. It was revealed that the incorporation of the drugs resulted in an increase in the viscosity of the hydrogels in comparison to the respective drug-free preparations. The dissolution study showed that not entire amount of the added drug was released from the formulation, suggesting an interaction between the carrier and the drug. The FTIR and DSC studies confirmed the bond formation between HA and both medicinal substances.


Asunto(s)
Hidrogeles , Tecnología Farmacéutica , Preparaciones de Acción Retardada , Tecnología Farmacéutica/métodos , Composición de Medicamentos , Cationes , Cinética , Solubilidad
4.
Int J Mol Sci ; 24(5)2023 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-36901749

RESUMEN

The aim of the study was to evaluate the effect of the peptide structure (WKWK)2-KWKWK-NH2, P4 (C12)2-KKKK-NH2, P5 (KWK)2-KWWW-NH2, P6 (KK)2-KWWW-NH2 on their physicochemical properties. The thermogravimetric method (TG/DTG) was used, which made it possible to observe the course of chemical reactions and phase transformations occurring during the heating of solid samples. Based on the DSC curves, the enthalpy of the processes occurring in the peptides was determined. The influence of the chemical structure of this group of compounds on their film-forming properties was determined using the Langmuir-Wilhelmy trough method and was followed by molecular dynamics simulation. Evaluated peptides showed high thermal stability and the first significant mass loss occurred only at about 230 °C and 350 °C. The analysis of the compressibility coefficient of individual peptides indicates that all formed peptide monolayers were in the expanded liquid phase. Their maximum compressibility factor was less than 50.0 mN/m. Its highest value of 42.7 mN/m was achieved in a monolayer made of P4. The results obtained in molecular dynamic simulation indicate that non-polar side chains played an important role in the properties of the P4 monolayer, and the same applies to P5, except that a spherical effect was observed here. A slightly different behavior was observed for the P6 and P2 peptide systems, where the type of amino acids present had an influence. The obtained results indicate that the structure of the peptide affected its physicochemical and layer-forming properties.


Asunto(s)
Péptidos , Termodinámica
5.
Int J Mol Sci ; 24(19)2023 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-37834308

RESUMEN

The aim of the study was to assess the effect of the synthesized antibacterial peptides: P2 (WKWK)2-KWKWK-NH2, P4 (C12)2-KKKK-NH2, P5 (KWK)2-KWWW-NH2, and P6 (KK)2-KWWW-NH2 on the physicochemical properties of a model biological membrane made of azolectin or lecithin. The Langmuir Wilhelmy method was used for the experiments. Based on the compressibility factor, it was determined that the monolayers formed of azolectin and peptides in the aqueous subphase are in the condensed liquid phase. At the boundary between the condensed and expanded liquid phases, there was a monolayer made of lecithin and P4, P5 or P6 in the aqueous subphase. In turn, the film consisting of lecithin alone (37.7 mN/m) and lecithin and P2 (42.6 mN/m) in the water subphase was in the expanded liquid phase. All peptides change, to varying degrees, the organization and packing of molecules in the monolayer, both those made of azolectin and of lecithin. The test results can be used for further research to design a system with the expected properties for specific organisms.


Asunto(s)
Lecitinas , Péptidos , Péptidos/farmacología , Agua/química , Propiedades de Superficie
6.
Polim Med ; 53(2): 111-116, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38054367

RESUMEN

BACKGROUND: Many substances are used to increase the viscosity of eye drops and reduce their surface tension. Their function is to prolong the persistence of the product on the surface of the eyeball and to increase the bioavailability of the pharmacologically active ingredient. OBJECTIVES: To investigate the surface tension of substances added to the eye drops, with the main aim of modulating properties of the preparation. MATERIAL AND METHODS: Five substances contained in solutions proposed for the development of eye drops were studied: sodium hyaluronate macromolecular (H-Na W), sodium hyaluronate ultramolecular (H-Na UM), hyaluronic acid 4% (K-H), methylcellulose (MC), and polyacrylic acid (PA). The main method was to study the surface tension using the du Noüy ring tensiometer. RESULTS: The research presented in this paper shows the various effects of different eye drop ingredients on the surface tension of the solutions. The surface tension values of PA solutions are in the range of 48.89-56.03 mN/m, of MC in the range of 68.94-89.32 mN/m, of K-H 54.54-65.66 mN/m, of H-Na UM 67.18-70.97 mN/m, and of H-Na W 67.09-71.73 mN/m. CONCLUSIONS: The use of different polymers affects the surface tension of model solutions proposed for use in ophthalmic preparations. Compounds containing carboxyl groups and anionic polymers have a similar effect on reducing the surface tension of the solution as classical surfactant compounds.


Asunto(s)
Ácido Hialurónico , Polímeros , Soluciones Oftálmicas , Tensión Superficial , Viscosidad
7.
Int J Mol Sci ; 23(15)2022 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-35955889

RESUMEN

(1) Background: Depending on the type of hydrophilic polymer used, different types of hydrogels may be chemically stable or may degrade and eventually disintegrate, or dissolve upon exposure to sunlight. Many over-the-counter medications are now stored with a limited control of temperature, humidity and lighting. Therefore, in this study, the photostability of a gel made of cross-linked polyacrylic acid (PA), methylcellulose (MC) and aristoflex (AV) was assessed, and the interaction between the polymers used and ascorbic acid and its ethylated derivative was investigated. (2) Methods: The samples were continuously irradiated at constant temperature for six hours. The stability of the substance incorporated into the gels was assessed using a UV-Vis spectrophotometer. FTIR-ATR infrared spectroscopy was used to measure changes during the exposure. (3) Results: Ascorbic acid completely decomposed between the first and second hours of illumination in all samples. The exception is the preparation based on polyacrylic acid with glycerol, in which the decomposition of ascorbic acid slowed down significantly. After six hours of irradiation, the ethylated ascorbic acid derivative decomposed in about 5% for the polyacrylic acid-based gels and aristoflex, and in the methylcellulose gel it decomposed to about 2%. In the case of ascorbic acid, the most stable formulation was a gel based on polyacrylic acid and polyacrylic acid with glycerol, and in the case of the ethyl derivative, a gel based on methylcellulose. (4) Conclusions: The experiment showed significant differences in the decomposition rate of both compounds, resulting from their photostability and the polymer used in the hydrogel.


Asunto(s)
Ácido Ascórbico , Glicerol , Ácido Ascórbico/química , Hidrogeles/química , Luz , Metilcelulosa/química , Polímeros/química
8.
Int J Mol Sci ; 23(23)2022 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-36499140

RESUMEN

The knowledge of interactions between different molecules is undoubtedly the driving force of all contemporary biomedical and biological sciences. Chemical biology/biological chemistry has become an important multidisciplinary bridge connecting the perspectives of chemistry and biology to the study of small molecules/peptidomimetics and their interactions in biological systems. Advances in structural biology research, in particular linking atomic structure to molecular properties and cellular context, are essential for the sophisticated design of new medicines that exhibit a high degree of druggability and very importantly, druglikeness. The authors of this contribution are outstanding scientists in the field who provided a brief overview of their work, which is arranged from in silico investigation through the characterization of interactions of compounds with biomolecules to bioactive materials.


Asunto(s)
Biología Molecular
9.
Int J Mol Sci ; 22(14)2021 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-34299085

RESUMEN

The ongoing search for effective treatment of Acne vulgaris is concentrated, i.a., on natural peptides with antimicrobial properties. The aim of this work was the development of new amino acid derivatives with potential activity on dermal infections against selected microorganisms, including the facultative anaerobe C. acne. The peptides P1-P6 were synthesized via Fmoc solid phase peptide synthesis using Rink amide AM resin, analyzed by RP-HPLC-MS, FTIR, DPPH radical scavenging activity, and evaluated against C. acne and S. aureus, both deposited and non-deposited in BC. Peptides P1-P6 presented a lack of cytotoxicity, antimicrobial activity, or antioxidative properties correlated with selected structural properties. P2 and P4-P6 sorption in BC resulted in variable data, i.a., confirming the prospective topical application of these peptides in a BC carrier.


Asunto(s)
Acné Vulgar/tratamiento farmacológico , Antibacterianos/farmacología , Antioxidantes/farmacología , Celulosa/metabolismo , Fragmentos de Péptidos/farmacología , Propionibacterium acnes/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Acné Vulgar/metabolismo , Humanos , Staphylococcus aureus/metabolismo
10.
Molecules ; 26(7)2021 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-33917516

RESUMEN

This study aimed to determine the effect of "annealing" acetylated potato starch with a homogenous granule size and various degrees of substitution on the thermal pasting characteristics (DSC), resistance to amylases, rheology of the prepared pastes, swelling power and dynamics of drug release. A fraction of large granules was separated from native starch with the sedimentation method and acetylated with various doses of acetic anhydride (6.5, 13.0 or 26.0 26 cm3/100 g starch). The starch acetates were then annealed at slightly lower temperatures than their pasting temperatures. The annealing process caused an almost twofold increase in the resistance to amylolysis and a threefold increase in the swelling power of the modified starch preparations. The heat of phase transition decreased almost two times and the range of starch pasting temperatures over two times, but the pasting temperature itself increased by ca. 10 °C. The 40 g/100 g addition of the modified starch preparation decreased the rate of drug release from a hydrogel by ca. one-fourth compared to the control sample.


Asunto(s)
Solanum tuberosum/química , Almidón/química , Anhídridos Acéticos/química , Acetilación , Tamaño de la Partícula , Transición de Fase , Temperatura
11.
Polim Med ; 51(1): 25-32, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34505758

RESUMEN

BACKGROUND: The pH of the skin surface is usually between 5.4 and 5.9 and functions as a barrier against bacteria and fungi; thus, the composition of the topically applied drug form may be of high importance for proper medication. OBJECTIVES: To evaluate the influence of the measurement conditions in aqueous solutions of ointments, creams, and gels, which include polymeric components, on the pH and conductivity results. MATERIAL AND METHODS: The pH and electrolytic conductivity of aqueous dispersions of commercially available ointments, creams and gels were tested and compared to reference vehicles. RESULTS: The results of the dilution method measurements of the pH and electrolytic conductivity of the ointment preparations are highly diverse, ranging from 5.88 to 6.27, whereas the reference pH for Unguentum simplex was between 5.40 and 5.43. Furthermore, the measurements of the pH and electrolytic conductivity with the dilution method for creams did not provide repeatable results with a small sample size, and the pH of commercial preparations was in the range between 5.79 and 6.37, compared to the reference pH of 5.23-5.46. However, the dilution method for measurements of the pH and electrolytic conductivity was suitable for hydrogel preparations and the obtained results were repeatable in the range of 6.11-6.90, while the reference preparations were in the range of 5.19-5.62. CONCLUSIONS: Evaluation methods of the electrolytic conductivity and pH of the preparations applied on the skin should be further evaluated; however, the pH of the commercial preparation seems to differ from the physiological skin pH, which covers the range of reference preparations.


Asunto(s)
Excipientes , Polímeros , Geles , Concentración de Iones de Hidrógeno , Pomadas
12.
Molecules ; 25(23)2020 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-33287276

RESUMEN

Targeted drug delivery systems are a very convenient method of treating inflammatory bowel disease. The properties of pectin make this biopolymer a suitable drug carrier. These properties allow pectin to overcome the diverse environment of the digestive tract and deliver the drug to the large intestine. This investigation proposed bipolymeric formulations consisting of the natural polymer pectin and a synthetic polymer containing the drug 5-aminosalicylic acid. Pectin beads were prepared via ionotropic gelation involving the interaction between the hydrophilic gel and calcium ions. The obtained formulations consisted of natural polymer, 5-aminosalicylic acid (5-ASA) and one of the synthetic polymers, such as polyacrylic acid, polyvinylpyrrolidone, polyethylene glycol or aristoflex. The release of the drug was carried out employing a basket apparatus (USP 1). The acceptor fluid was pH = 7.4 buffer with added enzyme pectinase to reflect the colon environment. The amount of the released drug was determined using UV-Vis spectrophotometry at a wavelength of λ = 330 nm. The kinetics of the drug dissolution revealed that none of the employed models was appropriate to describe the release process. A kinetic analysis of the release profile during two release stages was carried out. The fastest drug release occurred during the first stage from a formulation containing pectin and polyethylene glycol. However, according to the applied kinetic models, the dissolution of 5-ASA was rather high in the formulation without the synthetic polymer during the second stage. Depending on the formulation, 68-77% of 5-ASA was released in an 8-hour time period. The FTIR and DSC results showed that there was no interaction between the drug and the polymers, but interactions between pectin and synthetic polymers were found.


Asunto(s)
Preparaciones de Acción Retardada/química , Mesalamina/química , Pectinas/química , Polímeros/química , Calcio/química , Química Farmacéutica/métodos , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos/métodos , Geles/química , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Cinética
13.
Molecules ; 25(22)2020 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-33233773

RESUMEN

The aim of this study was to assess the photostability of quercetin in the presence of anionic and nonionic polymeric gels with varied compositions of an added component-glycerol. The samples were irradiated continuously at constant temperature. The stability of quercetin in solution and incorporated into the gels was evaluated by an UV-Vis spectrophotometer. FTIR spectroscopy (Fourier-transform infrared spectroscopy) was used to detect the changes in the structure of quercetin depending on the polymer used in the gel, and on the exposure time. Photostabilization is an important aspect of quality assurance in photosensitive compounds. The decomposition rate of quercetin in the ionic preparation of polyacrylic acid (PAA) with glycerol was 1.952·10-3 min-1, whereas the absence of glycerol resulted in a decay rate of 5.032·10-4 min-1. The formulation containing non-ionic methylcellulose resulted in a decomposition rate of quercetin in the range of 1.679·10-3 min-1. The decay rate of quercetin under light influence depended on the composition of the gel. It was found that the cross-linked PAA stabilized quercetin and the addition of glycerol accelerated the photodegradation.


Asunto(s)
Composición de Medicamentos , Quercetina/química , Rayos Ultravioleta , Geles/química , Modelos Moleculares , Estructura Molecular , Fotólisis/efectos de la radiación , Polímeros/química , Espectroscopía Infrarroja por Transformada de Fourier
14.
Molecules ; 24(6)2019 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-30909617

RESUMEN

Four stimuli-responsive polymers of N-isopropylacrylamide (NIPA) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPSA) and crosslinked derivatives by N,N'-methylene bisacrylamide (MBA) were synthesized: PNA, PAMPSA, PNAM, PAMPSAM. The effect of the cross-linker and methyl sulphonic acid (-CH3-SO3H) group on particle size, aggregation and volume phase transition temperature (VPTT) was investigated. Polymeric particles were synthesized via the surfactant free precipitation polymerization (SFPP) at 70 °C in the presence of cationic initiator 2,2'-azobis[2-methylpropionamidine] dihydrochloride (AMP) system. Chemical composition and morphology of investigated samples were evaluated using ATR-FTIR spectroscopy, ¹H-NMR spectrometry and SEM-EDS techniques. The hydrodynamic diameters (HD), zeta potential (ZP), and polydispersity index (PDI) in aqueous dispersions were assessed by dynamic light scattering (DLS) between 18⁻42 °C. HD values at 18 °C for PNA, PAMPSA, PNAM, PAMPSAM polymers were approx. 32, 730, 715, 665 nm, and ZP values were -1.36, -0.01, 8.90, -0.09 mV, respectively. The VPTT range was observed between 29 and 41 °C. PDI's for PNA and PNAM were low and varied between 0.276 and 0.460, and between 0.119 and 0.056, respectively. PAMPSA and PAMPSAM were characterized by higher PDI in the range 0.728⁻0.959 and 0.658⁻0.836, respectively. The results confirmed the thermal sensitivity of the synthesized polymers and indicated a significant polydispersity and aggregation tendency of the resulting molecules. The conductivity results were applied for the interpretation of the polymerization process.


Asunto(s)
Acrilamidas/química , Alcanosulfonatos/química , Portadores de Fármacos/química , Microesferas , Acrilamidas/síntesis química , Resinas Acrílicas/química , Alcanosulfonatos/síntesis química , Portadores de Fármacos/síntesis química , Conductividad Eléctrica , Humanos , Tamaño de la Partícula , Transición de Fase , Polimerizacion , Polímeros/química , Ácidos Sulfónicos/química , Temperatura
15.
Molecules ; 24(4)2019 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-30781578

RESUMEN

The past decade may be considered as revolutionary in the research field focused on the physiological function of macrophages. Unknown subtypes of these cells involved in pathological mechanisms were described recently, and they are considered as potential drug delivery targets. The innate ability to internalize foreign bodies exhibited by macrophages can be employed as a therapeutic strategy. The efficiency of this uptake depends on the size, shape and surface physiochemical properties of the phagocyted objects. Here, we propose a method of preparation and preliminary evaluation of drug-polymer conjugate-based microspheres for macrophage targeted drug delivery. The aim of the study was to identify crucial uptake-enhancing parameters for solid, surface modified particles. A model drug molecule-lamivudine-was conjugated with poly-ε-caprolactone via ring opening polymerization. The conjugate was utilized in a solvent evaporation method technique to form solid particles. Interactions between particles and a model rat alveolar cell line were evaluated by flow cytometry. The polymerization product was characterized by a molecular weight of 3.8 kDa. The surface of the obtained solid drug-loaded cores of a hydrodynamic diameter equal to 2.4 µm was modified with biocompatible polyelectrolytes via a layer-by-layer assembly method. Differences in the internalization efficiency of four particle batches by the model RAW 264.7 cell line suggest that particle diameter and surface hydrophobicity are the most influential parameters in terms of phagocytic uptake.


Asunto(s)
Fármacos Anti-VIH/administración & dosificación , Caproatos/administración & dosificación , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos , Lactonas/administración & dosificación , Lamivudine/administración & dosificación , Macrófagos/metabolismo , Animales , Fármacos Anti-VIH/química , Caproatos/química , Supervivencia Celular/efectos de los fármacos , Combinación de Medicamentos , Lactonas/química , Lamivudine/química , Macrófagos/inmunología , Espectroscopía de Resonancia Magnética , Ratones , Microesferas , Fagocitosis , Polímeros/metabolismo , Células RAW 264.7 , Análisis Espectral
16.
Int J Mol Sci ; 19(12)2018 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-30501085

RESUMEN

Liposomes containing a certain amount of ethanol are often referred to in the literature as ethosomes. Liposomes vary in size from 25 nm to 25,000 nm. Ethosomes are defined as lipids composed of phospholipids, ethanol, or isopropyl alcohol in quite high concentrations, and water. They enable active substances to reach the deep skin layers or even the general circulation. The structure of ethosomes allows for an increased penetration of the drug through two effects: the ethanolic effect and the ethosomal effect. Ethosomes can be obtained using three methods: the hot method, the cold method, and the classic method of mechanical dispersion. The literature describes many of the therapeutic groups of drugs that can be enclosed in ethosomal formulations. These include anti-viral drugs, antineoplastic drugs, antifungal drugs, hypnotic drugs, hormones, and many others. Ethosomes show important practical advantages compared to classic liposomes. It is necessary to conduct research with regard to real pharmaceutical systems using advanced physicochemical techniques.


Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Etanol/química , Liposomas/química , Liposomas/metabolismo , Animales
17.
Biol Pharm Bull ; 40(8): 1199-1206, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28769001

RESUMEN

The aim of the work was the evaluation of selected biological and physicochemical, applicative properties of ethylated ascorbic acid (AAE) compared to ascorbic acid (AA). Thermogravimetry (TG), differential thermogravimetry (DTG), and differential thermal analysis (DTA) were conducted, followed by the evaluation of AAE decomposition by the UV-Vis spectroscopic method including the influence of temperature and pH. Scavenging, antimicrobial activity and cytotoxicity against L929 fibroblasts were also performed. The difference in mass loss between AA and AAE was 30% via TG. DTA revealed characteristic exothermic and endothermic effects. The AAE solution was more thermally stable than AA. The calculated zero-order rate constants of free-radical scavenging kinetics for AAE were in the range of 4.9×10-3-1.35×10-2 s-1. The activation energy for the process was 11,2281 kJ/mol. AAE was active against Staphylococcus (S.) aureus and Enterococcus (E.) faecalis and acted stronger against Candida (C.) albicans than AA. The concentrations of AA ≥2.5% were cytotoxic, whereas in the case of AAE, a 10% concentration was considered cytotoxic. DTG enables the detailed differentiation between AA and AAE. AAE in aqueous solution is more stable compared to AA. The antioxidant activity of AAE is significant. However, the reaction with 2,2-diphenyl-1-picrylhydrazyl (DPPH) indicates prolonged activity compared to AA. Variability in the antimicrobial activity of AAE may find practical application in the pharmaceutical and cosmetic industries. The potential for applicative aims may be supported by the relatively low in vitro toxicity of AAE.


Asunto(s)
Ácido Ascórbico/análogos & derivados , Animales , Antiinfecciosos/química , Antiinfecciosos/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Ácido Ascórbico/química , Ácido Ascórbico/farmacología , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Compuestos de Bifenilo/metabolismo , Candida albicans/efectos de los fármacos , Candida albicans/crecimiento & desarrollo , Línea Celular , Supervivencia Celular/efectos de los fármacos , Estabilidad de Medicamentos , Concentración de Iones de Hidrógeno , Ratones , Picratos/metabolismo , Termogravimetría
18.
Acta Pol Pharm ; 74(1): 227-233, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29474778

RESUMEN

The ring opening polymerization of ε-caprolactone catalyzed by organic acids had been studied. The aim of this study was to develop and optimize a process for obtaining poly-ε-caprolactone of high purity intend- ed for use as a drug carrier, with consideration of the impct of the monomer-catalyst ratio on the product parameters, the temperature impact and the impact of the type of catalyst on the product properties. The studies also aim to determine the possible positive effect of microwave radiation on the course of the reaction. The structures of the synthesized compounds were proven by 'H NMR spectroscopy. The average molecular weight of the obtained polymer particles was estimated based on the relations of the 'H NMR signal integrations. In the reaction catalyzed by citric acid the product was characterized by a substantially higher molecular weight compared to the analogous reaction using another type of catalysts. Higher average molecular weights were obtained by conducting the reactions under microwave radiation.


Asunto(s)
Portadores de Fármacos , Microondas , Poliésteres/química , Catálisis , Espectroscopía de Resonancia Magnética , Peso Molecular , Polimerizacion
19.
Acta Pol Pharm ; 74(1): 199-209, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29474776

RESUMEN

For modem drug delivery, new drug carriers sensitive to various factors and with size in the range of micro- and nanometers are required. The aim of this work was to evaluate the influence of hydrophilic and hydrophobic co-monomers on the hydrodynamic diameter of three co-polymers of N-isopropylacrylamide (NIPA) nanogels synthesized at 70*C in the presence of potassium persulfate (KPS) as the initiator and N.N'-methylene bis-acrylamide (MBA) as the cross-linker. The first batch of nanoparticles was synthesized without co-monomer, whereas poly(ethylene glycol) methyl ether acrylate (PEG-MEA), and N-teii-butylacrylamide (NTB), were implemented as co-monomers for the second and third batch. Hydrodynamic diameter of nanoparticles was in the range 550-800 rn. The compositions of the synthesized co-polymer nanoparticles were con- firmed via IR and NMR analyses. The SFPP conditions resulted in hydrodynamic diameters ranging from approximately 550 to 800 nm at temperatures lower than the volume phase transition temperature (VPTT) and diameters ranging from 250 to 600 nm at temperatures above the VPTT, where the VPTT was between 26 and 41'C. The polydispersity index (PDI) showed a maximum or a minimum value at the VPTT, which was an important indicator of the volume phase transition. According to the PDI observation during thermal cycling, the addition of NTB into the polymeric chain resulted in maximal values of the PDI at the VPIT, similar to the case of nanoparticles without any additional co-monomers. In contrast, in the case of PEG-MEA, the PDI presented a minimal value. Dynamic light scattering (DLS) volume measurements, performed simultaneously with spectral methods, may lead to a fast evaluation of nanoparticles prepared by SFPP.


Asunto(s)
Acrilamidas/química , Sistemas de Liberación de Medicamentos , Portadores de Fármacos , Hidrodinámica , Interacciones Hidrofóbicas e Hidrofílicas , Espectroscopía de Resonancia Magnética , Nanogeles , Nanopartículas/química , Transición de Fase , Polietilenglicoles , Polietileneimina , Temperatura
20.
Molecules ; 22(1)2016 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-28035967

RESUMEN

The aim of the study was to monitor the influence of increasing initiator concentrations on the properties of poly-N-isopropylacrylamide (polyNIPA) nanoparticles obtained via surfactant free precipitation polymerization (SFPP). In all studied systems P-001 to P-1, the same amount of monomer was used, and increasing amounts of potassium persulphate (KPS). The course of each reaction was monitored by measuring the conductivity of the whole system. The resulting composition of products was confirmed by attenuated total reflectance within Fourier transformed infrared spectroscopy (ATR-FTIR) measurements. The hydrodynamic diameters with polydispersity index (PDI) and zeta potential (ZP) were measured in aqueous dispersions of the synthesized polymers in dynamic light scattering (DLS) device (λ = 678 nm), and were found to be for P-1: 20.33 nm (PDI = 0.49) and -7 mV, for P-05: 22.24 nm (PDI = 0.39) and -5 mV, for P-01: 50.14 nm (PDI = 0.49) and -3 mV, for P-005: 62.75 nm (PDI = 0.54) and -3 mV and for P-001: 509.4 nm (PDI = 0.61) and -12 mV at 18 °C, respectively. Initiator concentration affects the size and ZP of particles. The hydrodynamic diameter decreases with initiator concentration increase, whereas the time of the reaction decreases when the initiator concentration increases. This fact is reflected in the observed values of conductivity in the course of the performed reaction. Evaluated volume phase transition temperature in the range of 32 °C enables further research of the nanoparticles as thermosensitive drug carriers.


Asunto(s)
Resinas Acrílicas/química , Preparaciones de Acción Retardada , Nanopartículas/química , Compuestos de Potasio/química , Sulfatos/química , Conductividad Eléctrica , Tamaño de la Partícula , Transición de Fase , Polimerizacion , Temperatura
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