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1.
Molecules ; 29(5)2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-38474457

RESUMEN

This study presents a simple and energy-efficient self-assembly LAG synthetic method for novel water-soluble copper(I) complexes [Cu(terpy)(PTA)][PF6] (1) and [Cu(terpy)(PTA)2][PF6] (2). They were characterized by FT-IR, 1H, and 31P{1H} NMR spectroscopy, elemental analysis, and single-crystal/powder X-ray diffraction (for 2). The X-ray analysis of compound 2 indicates a bidentate coordination mode of terpyridine to the metal center. Variable-temperature NMR tests indicate dynamic properties for terpyridine in the case of both compounds, as well as for the PTA ligands in the case of 2. Additionally, compounds 1 and 2 exhibit interesting cytotoxic activity, which was tested on normal human dermal fibroblasts (NHDFs), human lung carcinoma (A549), human breast adenocarcinoma (MCF-7), and human cervix carcinoma (HeLa) established cell lines. In comparison to the other tested compounds, complexes 1 and 2 seem to have significantly lower IC50 values against cancer cells (A549, HeLa, MCF-7), indicating their potential as prospective anticancer agents. Moreover, both compounds show no significant toxicity towards normal skin cells (NHDFs), suggesting a certain selectivity in their action on cancer cells. Cisplatin as a reference compound also exhibited considerable cytotoxicity against cancer cells but with a low level of selectivity, which could lead to unwanted effects on normal cells. Remarkably, compounds 1 and 2 exhibit up to 30 times the cytotoxic activity of cisplatin, with a six-fold lower toxicity to normal cells. They also interact strongly with human serum albumin, suggesting potential therapeutic applications. Overall, these compounds hold significant promise as potential chemotherapeutic agents.


Asunto(s)
Adamantano/análogos & derivados , Antineoplásicos , Carcinoma , Complejos de Coordinación , Compuestos Organofosforados , Femenino , Humanos , Cisplatino/farmacología , Cobre/química , Línea Celular Tumoral , Agua , Estudios Prospectivos , Espectroscopía Infrarroja por Transformada de Fourier , Complejos de Coordinación/química , Antineoplásicos/farmacología , Ligandos
2.
Pharmacol Rep ; 75(1): 128-165, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36401763

RESUMEN

BACKGROUND: Epilepsy frequently coexists with neuropathic pain. Our approach is based on the search for active compounds with multitarget profiles beneficial in terms of potential side effects and on the implementation of screening for potential multidirectional central activity. METHODS: Compounds were synthesized by means of chemical synthesis. After antiseizure and neurotoxicity screening in vivo, KM-408 and its enantiomers were chosen for analgesic activity evaluations. Further safety studies included acute toxicity in mice, the effect on normal electrocardiogram and on blood pressure in rats, whole body plethysmography in rats, and in vitro and biochemical assays. Pharmacokinetics has been studied in rats after iv and po administration. Metabolism has been studied in vivo in rat serum and urine. Radioligand binding studies were performed as part of the mechanism of action investigation. RESULTS: Selected results for KM-408: Ki sigma = 7.2*10-8; Ki 5-HT1A = 8.0*10-7; ED50 MES (mice, ip) = 13.3 mg/kg; formalin test (I phase, mice, ip)-active at 30 mg/kg; SNL (rats, ip)-active at 6 mg/kg; STZ-induced pain (mice, ip)-active at 1 mg/kg (von Frey) and 10 mg/kg (hot plate); hot plate test (mice, ip)-active at 30 mg/kg; ED50 capsaicin test (mice, ip) = 18.99 mg/kg; tail immersion test (mice)-active at 0.5%; corneal anesthesia (guinea pigs)-active at 0.125%; infiltration anesthesia (guinea pigs)-active at 0.125%. CONCLUSIONS: Within the presented study a novel compound, R,S-2-((2-(2-chloro-6-methylphenoxy)ethyl)amino)butan-1-ol hydrochloride (KM-408) with dual antiseizure and analgesic activity has been developed for potential use in neuropathic pain treatment.


Asunto(s)
Epilepsia , Neuralgia , Ratas , Ratones , Animales , Cobayas , Anticonvulsivantes/farmacología , Anticonvulsivantes/uso terapéutico , Neuralgia/tratamiento farmacológico , Analgésicos/farmacología , Analgésicos/uso terapéutico , Epilepsia/tratamiento farmacológico , Capsaicina , Modelos Animales de Enfermedad
3.
Eur J Pharmacol ; 886: 173540, 2020 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-32896552

RESUMEN

Anticonvulsant drugs are used to treat a wide range of non-epileptic conditions, including chronic, neuropathic pain. We obtained a phenoxyalkylaminoalkanol derivative, KM-416 which had previously demonstrated a significant anticonvulsant activity and had also been shown to bind to 5-HT1A, α2-receptors and SERT and not to exhibit mutagenic properties. As KM-416 is a promising compound in our search for drug candidates, in the present study we further assessed its pharmacological profile (analgesic, local anesthetic, and antidepressant-like activities) accompanied with patch-clamp studies. Considering the importance of drug safety, its influence on the cardiovascular system was also evaluated. Moreover, KM-416 was subjected to forced degradation and pharmacokinetic studies to examine its stability and pharmacokinetic parameters. KM-416 revealed a significant antinociceptive activity in the tonic - the formalin test, neurogenic - the capsaicin test, and neuropathic pain model - streptozotocin-induced peripheral neuropathy. Moreover, it exerted a local anesthetic effect. In addition, KM-416 exhibited anti-depressant like activity. The results from the patch-clamp studies indicated that KM-416 can inhibit currents elicited by activation of NMDA receptors, while it also exhibited a voltage-dependent inhibition of Na+ currents. KM-416 did not influence ventricular depolarization and repolarization. Following oral administration, pharmacokinetics of KM-416 was characterized by a rapid absorption in the rat. The brain-to-plasma AUC ratio was 6.7, indicating that KM-416 was well distributed to brain. The forced degradation studies showed that KM-416 was very stable under stress conditions. All these features made KM-416 a promising drug candidate for further development against neuropathic pain and epilepsy.


Asunto(s)
Analgésicos/farmacología , Anestésicos Locales/farmacología , Anticonvulsivantes/farmacología , Antidepresivos/farmacología , Analgésicos/química , Analgésicos/farmacocinética , Anestésicos Locales/química , Anestésicos Locales/farmacocinética , Animales , Anticonvulsivantes/química , Anticonvulsivantes/farmacocinética , Antidepresivos/química , Antidepresivos/farmacocinética , Área Bajo la Curva , Encéfalo/metabolismo , Capsaicina/farmacología , Neuropatías Diabéticas/tratamiento farmacológico , Estabilidad de Medicamentos , Epilepsia , Cobayas , Hemodinámica/efectos de los fármacos , Masculino , Ratones , Neuralgia/tratamiento farmacológico , Dimensión del Dolor , Técnicas de Placa-Clamp , Ratas , Ratas Wistar , Bloqueadores de los Canales de Sodio/farmacología
4.
Pharmaceutics ; 12(2)2020 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-32079113

RESUMEN

The pharmacokinetic profile and tissue uptake of daidzein (DAI) was determined in rat serum and tissues (lungs, eyes, brain, heart, spleen, fat, liver, kidney, and testes) after intravenous and intraperitoneal administration of DAI in suspension or complexed with ethylenediamine-modified γ-cyclodextrin (GCD-EDA/DAI). The absolute and relative bioavailability of DAI suspended (20 mg/kg i.v. vs. 50 mg/kg i.p.) and complexed (0.54 mg/kg i.v. vs. 1.35 mg/kg i.p.) was determined. After i.p. administration, absorption of DAI complexed with GCD-EDA was more rapid (tmax = 15 min) than that of DAI in suspension (tmax = 45 min) with a ca. 3.6 times higher maximum concentration (Cmax = 615 vs. 173 ng/mL). The i.v. half-life of DAI was longer in GCD-EDA/DAI complex compared with DAI in suspension (t0.5 = 380 min vs. 230 min). The volume of distribution of DAI given i.v. in GCD-EDA/DAI complex was ca. 6 times larger than DAI in suspension (38.6 L/kg vs. 6.2 L/kg). Our data support the concept that the pharmacokinetics of DAI suspended in high doses are nonlinear. Increasing the intravenous dose 34 times resulted in a 5-fold increase in AUC. In turn, increasing the intraperitoneal dose 37 times resulted in a ca. 2-fold increase in AUC. The results of this study suggested that GCD-EDA complex may improve DAI bioavailability after i.p. administration. The absolute bioavailability of DAI in GCD-EDA inclusion complex was ca. 3 times greater (F = 82.4% vs. 28.2%), and the relative bioavailability was ca. 21 times higher than that of DAI in suspension, indicating the need to study DAI bioavailability after administration by routes other than intraperitoneal, e.g., orally, subcutaneously, or intramuscularly. The concentration of DAI released from GCD-EDA/DAI inclusion complex to all the rat tissues studied was higher than after administration of DAI in suspension. The concentration of DAI in brain and lungs was found to be almost 90 and 45 times higher, respectively, when administered in complex compared to the suspended DAI. Given the nonlinear relationship between DAI bioavailability and the dose released from the GCD-EDA complex, complexation of DAI may thus offer an effective approach to improve DAI delivery for treatment purposes, for example in mucopolysaccharidosis (MPS), allowing the reduction of ingested DAI doses.

5.
Pharmaceutics ; 12(1)2019 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-31861803

RESUMEN

Topical treatment modalities have multiple advantages starting with the convenient application and non-invasive treatment and ending with the reduction of the risk of the systemic side effects. Active pharmaceutical substances must reach the desired concentration at the target site in order to produce a particular therapeutic effect. In contrast to other dosage forms topical agents applied to the skin may also be susceptible to photodegradation after application. That is why the knowledge of the susceptibility of these topical drugs to UV irradiation, which may contribute to their degradation or changes in chemical structure, is very important. Active pharmaceutical substances used in dermatology may differ both in chemical structure and photostability. Furthermore, various factors-such as light intensity and wavelength, pH, temperature, concentration-can influence the photodegradation process, which is reflected in particular in kinetics of photodegradation of active pharmaceutical substances as well as both the quantitative and qualitative composition of by-products. The aim of this study was to conduct a systematic review of the photostability of dermatological drugs, as well as of other substances commonly applied topically. The photostability of glucocorticosteroids, retinoids, and antifungal drugs as well as non-steroidal anti-inflammatory drugs applied topically and selected UV-filters have been discussed. Furthermore, the impact of photoinstability on the effectiveness of pharmacotherapy and some photostabilization strategies have been also included.

6.
Kardiochir Torakochirurgia Pol ; 15(3): 188-195, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30310399

RESUMEN

Surgical treatment of severe aortic stenosis offers good early and long-term results, even in elderly patients. Despite the implementation of percutaneous methods for the very high-risk group, surgical valve replacement remains the gold standard. The advanced age of patients should not be the only indicator limiting the possibility of surgery. In this review we present the most important information on the results of aortic stenosis surgical treatment in the groups of older patients. New methods such as percutaneous and minimally invasive methods of surgery are also discussed. Additionally, the presented information is referred to current guidelines for the treatment of severe aortic stenosis.

7.
J AOAC Int ; 101(3): 708-713, 2018 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-28882196

RESUMEN

A new chromatographic-densitometric method has been developed for the qualitative and quantitative determination of the active ingredients in a simulated mixture corresponding to the PolyIran polypill, composed of acetylsalicylic acid, hydrochlorothiazide (HCT), enalapril (ENA), and atorvastatin (ATR), whose efficacy in the treatment and prevention of cardiovascular disease has been documented in clinical trials. Chromatographic separation was performed using TLC silica gel 60 plates with fluorescent indicator F254 as the stationary phase and a mixture of n-hexane-ethyl acetate-methanol-water-acetic acid (8.4 + 8 + 3 + 0.4 + 0.2, v/v/v/v/v) as the mobile phase. Densitometric measurements were carried out at λ = 210 nm when determining ENA and at λ = 265 nm in the case of the other drugs. Peaks of examined substances were well separated in the recorded chromatograms, enabling the evaluation of the results in terms of both qualitative and quantitative analysis. The method was specific for the analyzed components and was characterized by high sensitivity. The LOD was between 0.043 and 0.331 µg/spot, and LOQ was between 0.100 and 0.942 µg/spot. Recovery was in the range of 97.02-101.34%. The linearity range was broad and ranged from 0.600 to 6.000 µg/spot for acetylsalicylic acid, from 0.058 to 1.102 µg/spot for HCT, from 0.505 to 6.560 µg/spot for ENA, and from 0.100 to 1.000 µg/spot for ATR. The method was characterized by good precision, with RSD values that ranged from 0.10 to 2.26%.


Asunto(s)
Aspirina/análisis , Atorvastatina/análisis , Cromatografía en Capa Delgada/métodos , Densitometría/métodos , Enalapril/análisis , Hidroclorotiazida/análisis , Cardiotónicos/análisis , Composición de Medicamentos , Límite de Detección , Reproducibilidad de los Resultados
8.
Dalton Trans ; 46(30): 10073-10081, 2017 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-28731114

RESUMEN

A series of novel ruthenium(ii) 2,2'-bipyridyl (bpy) and 1,10-phenanthroline (phen) derivatives containing PTA (1,3,5-triaza-7-phosphaadamantane) or mPTA (N-methyl-1,3,5-triaza-7-phosphaadamantane cation) have been synthesized and fully characterized. Three types of complexes have been obtained, neutral [Ru(N-N)(PTA)2Cl2] (1, N-N = bpy and 4, N-N = phen), monocationic [Ru(N-N)(PTA)3Cl][Cl] (2, N-N = bpy and 5, N-N = phen) and dicationic [Ru(N-N)(mPTA)Cl2][BF4]2 (3, N-N = bpy and 6, N-N = phen). The solid-state structures of four complexes have been determined by single-crystal X-ray diffraction. The cytotoxicity of the complexes has been evaluated in vitro against U266 and RPMI human multiple myeloma cells.


Asunto(s)
2,2'-Dipiridil/química , Adamantano/análogos & derivados , Antineoplásicos/farmacología , Proliferación Celular/efectos de los fármacos , Complejos de Coordinación/farmacología , Mieloma Múltiple/patología , Compuestos Organofosforados/química , Fenantrolinas/química , Rutenio/química , Adamantano/química , Antineoplásicos/síntesis química , Antineoplásicos/química , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Complejos de Coordinación/síntesis química , Complejos de Coordinación/química , Cristalografía por Rayos X , Humanos , Nitrógeno/química
9.
Anaerobe ; 44: 27-33, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28104533

RESUMEN

Porphyromonas gingivalis is a major etiologic agent and a key pathogen responsible for the development and progression of chronic periodontitis. Controlling the number of periodontal pathogens is one of the primary actions for maintaining oral health; therefore, active compounds with a capacity to exert antimicrobial activity have received considerable attention as they may represent potential new therapeutic agents for the treatment of chronic periodontitis. Heterocyclic compounds possessing 1,2,4- or 1,2,3-triazoles are known for several biological activities, including antibacterial properties. Among them are stable hemiaminals which can be obtained in reaction between nitrobenzaldehyde derivatives and 4-amino-1,2,4-triazole or 4-amino-3,5-dimethyl-1,2,4-triazole. In this study, we selected two relatively stable hemiaminals: (2,4-dinitrophenyl)(4H-1,2,4-triazole-4-ylamino)methanol (24DNTAM) and (2,4-dinitrophenyl)(4H-3,5-dimethyl-1,2,4-triazole-4-ylamino)methanol (24DNDMTAM). Both compounds showed promising anti-P. gingivalis activity, higher against ATCC 33277 strain as compared to A7436 strain. The lowest hemiaminal concentration inhibiting visible planktonic bacterial growth under high-iron/heme conditions was ∼0.06 mg/ml, and the lowest hemiaminal concentration showing killing of bacteria was ∼0.25 mg/ml. Antimicrobial activity was also observed against P. gingivalis grown on blood agar plates. Slightly higher antimicrobial activity of both compounds was observed when P. gingivalis was grown in co-cultures with epithelial HeLa cells under low-iron/heme conditions, which mimic those occurring in vivo. 24DNTAM was more effective against P. gingivalis, but exhibited higher cytotoxic activity against epithelial and red blood cells, as compared with 24DNDMTAM. We conclude that both hemiaminals might originate a novel group of biologically important molecules.


Asunto(s)
Antibacterianos/farmacología , Porphyromonas gingivalis/efectos de los fármacos , Triazoles/farmacología , Antibacterianos/síntesis química , Técnicas de Cocultivo , Células Epiteliales/microbiología , Células Epiteliales/fisiología , Células HeLa , Humanos , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Modelos Moleculares , Estructura Molecular , Porphyromonas gingivalis/crecimiento & desarrollo , Triazoles/síntesis química
10.
Acta Pol Pharm ; 74(1): 93-102, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29474765

RESUMEN

The usefulness of derivative spectrophotometry for the determination of labetalol, sotalol and oxprenolol in binary mixtures and in human spiked serum was checked. To this aim a spectrophotometric analysis of samples in the UV range was carried out and the obtained results revealed that derivative spectropho- tometry allows for the fast, accurate and precise determination of the tested substances in spite of their clear interference in the zero-order spectra. For quantitative determinations "zero-crossing" technique was used to establish wavelengths for zeros of specified component. In a mixture of labetalol and oxprenolol the following wavelengths were established: D1 λ = 245.32 nm and 266.03 nm, D2 λ = 243.30 nm and 301.09 nm. respectively. D3 derivative did not show zeros suitable for quantitative analysis. For the analysis of labetalol and sotalol mixture, D3 derivative spectrophotometry was used at the following wavelengths: = 246.03 nm and λ = 249.91 rum, respectively. In this case, the curves of Dl and D2 derivatives showed no zeros that can be used in quantitative analysis. To determine the concentration of the components in a mixture containing oxprenolol and sotalol the following wavelengths were selected: for oxprenolol DI λ = 245.32 nm, D2 λ = 240.18 run, D3 λ = 232.05 nm and for sotalol Dl λ = 230.56 nm, D2 Xλ= 232.65 nm and D3 X = 238.84 tm, respectively. The developed spectrophotometric method was characterized by high sensitivity and accuracy, LOD determined for sotalol was in the range of 0.21-1.88 µg/mL, for labetalol 1.00-3.43 µg/mL and for oxprenolol 0.16-2.06 µg/mL; LOQ determined for sotalol was in the range of 0.65-5.70 µg/mL, for labetalol 3.11-10.39 µg/mL and for oxprenolol 0.47-6.23 µg/mL, depending on the composition of the tested mixture and the order of the deriv- ative. The recovery of the individual components was within the range of 100 ± 5%. The linearity range was wide and estimated for sotalol in the range of 11.00-38.50 µg/mL, for labetalol 12.80-44.80 µg/mL and for oxprenolol 12.60-44.10 µg/mL with correlation coefficients in the range of 0.9977-0.9999.


Asunto(s)
Labetalol/análisis , Oxprenolol/análisis , Sotalol/análisis , Espectrofotometría Ultravioleta/métodos , Humanos , Límite de Detección
11.
Acta Pharm ; 67(4): 463-478, 2017 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-29337671

RESUMEN

Applicability of derivative spectrophotometry for the determination of valsartan in the presence of a substance from the group of statins was checked. The obtained results indicate that the proposed method may be effective by using appropriate derivatives: for valsartan and fluvastatin - D1, D2 and D3, for valsartan and pravastatin - D1 and D3, for valsartan and atorvastatin - D2 and D3. The method was characterized by high sensitivity and accuracy. Linearity was maintained in the following ranges: 9.28-32.48 mg mL-1 for valsartan, 8.16-28.56 mg mL-1 f or fluvastatin, 14.40-39.90 mg mL-1 for atorvastatin and 9.60-48.00 mg mL-1 for pravastatin. Determination coefficients were in the range of 0.989-0.999 depending on the analyte and the order of derivative. The precision of the method was high with RSD from 0.1 to 2.5 % and recovery of individual components was within the range of 100 ± 5 %. The developed method was successfully applied to the determination of valsartan combined with fluvastatin, atorvastatin and pravastatin in laboratory prepared mixtures and in pharmaceutical preparations.


Asunto(s)
Inhibidores de Hidroximetilglutaril-CoA Reductasas/análisis , Espectrofotometría/métodos , Valsartán/análisis , Atorvastatina/análisis , Ácidos Grasos Monoinsaturados/análisis , Fluvastatina , Indoles/análisis , Pravastatina/análisis , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
12.
Kardiochir Torakochirurgia Pol ; 12(2): 103-10, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26336491

RESUMEN

Over the last twenty years, minimally invasive aortic valve replacement (MIAVR) has evolved into a safe, well-tolerated and efficient surgical treatment option for aortic valve disease. It has been shown to reduce postoperative morbidity, providing faster recovery and rehabilitation, shorter hospital stay and better cosmetic results compared with conventional surgery. A variety of minimally invasive accesses have been developed and utilized to date. This concise review demonstrates and discusses surgical techniques used in contemporary approaches to MIAVR and presents the most important results of MIAVR procedures.

13.
Molecules ; 20(8): 14365-76, 2015 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-26258772

RESUMEN

Stable hemiaminals can be obtained in the one-pot reaction between 2-aminopyrimidine and nitrobenzaldehyde derivatives. Ten new hemiaminals have been obtained, six of them in crystal state. The molecular stability of these intermediates results from the presence of both electron-withdrawing nitro groups as substituents on the phenyl ring and pyrimidine ring, so no further stabilisation by intramolecular interaction is required. Hemiaminal molecules possess a tetrahedral carbon atom constituting a stereogenic centre. As the result of crystallisation in centrosymmetric space groups both enantiomers are present in the crystal structure.


Asunto(s)
Aminas/química , Pirimidinas/química , Cristalización , Enlace de Hidrógeno , Conformación Molecular , Pirimidinas/síntesis química
14.
J Hazard Mater ; 298: 146-53, 2015 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-26024615

RESUMEN

Photocatalytic degradation of an antibiotic, sulfamethoxazole (SMX), in aqueous solution using a novel floating TiO2-expanded perlite photocatalyst (EP-TiO2-773) and radiation from the near UV spectral range was studied. The process is important considering that SMX is known to be a widespread and highly persistent pollutant of water resources. SMX degradation was described using a pseudo-first-order kinetic equation according to the Langmuir-Hinshelwood model. The products of the SMX photocatalytic degradation were identified. The effect of pH on the kinetics and mechanism of SMX photocatalytic degradation was explained.


Asunto(s)
Óxido de Aluminio/química , Antibacterianos/química , Dióxido de Silicio/química , Sulfametoxazol/química , Titanio/química , Catálisis , Concentración de Iones de Hidrógeno , Cinética , Fotoquímica , Soluciones , Espectrofotometría Ultravioleta , Agua
15.
Molecules ; 19(8): 11160-77, 2014 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-25079658

RESUMEN

Under neutral conditions the reactions between 4-amino-1,2,4-triazole and cyano-substituted benzaldehyde derivatives yield stable hemiaminals. Addition of small amounts of acid catalyst promotes further step of dehydration resulting in formation of Schiff bases. Four new hemiaminals and the corresponding imines have been obtained. The molecular stability of the hemiaminal intermediates results from both the 1,2,4-triazole moiety and electron withdrawing substituents on the phenyl ring, so no further stabilisation by intramolecular interaction is required. Hemiaminal molecules possess stereogenic centres on carbon and nitrogen atoms. The chirality of these centres is strongly correlated with the conformation of the molecules due to heteroatom hyperconjugation effects.


Asunto(s)
Triazoles/química , Catálisis , Modelos Moleculares , Estructura Molecular , Bases de Schiff/síntesis química , Bases de Schiff/química
16.
Acta Pol Pharm ; 70(4): 643-52, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23923388

RESUMEN

The purpose of this work was to develop a sensitive stability indicating TLC-densitometric method for the determination of betaxolol (Bx) in pharmaceutical preparations and to study the stability of Bx in acidic solutions. The method was developed on TLC aluminium plates precoated with silica gel F254using the mobile phase chloroform-methanol-ammonia 25% (18 : 4: 0.2, v/v/v) which gives compact spots for Bx (R(f) approximately equal to 0.64) and its degradation product (R(f) approximately equal to 0.39). Densitometric analysis was carried out in UV at 280 nm. The developed method is highly sensitive (LOD = 66.6 ng/spot, LOQ = 200 ng/spot), precise (RSD = 2.73%) and accurate (mean recovery = 100.28% at 100% level). Bx was subjected to acidic and alkaline hydrolysis but degradation was observed only in acidic solutions. The degradation process was described with kinetic and thermodynamic parameters. Based on LC-ESI/MS analysis, it was found that Bx decomposes in acidic solution to produce ethoxyphenoxy-3-[(1-methylethyl)amino]propan-2-ol.


Asunto(s)
Betaxolol/análisis , Cromatografía Liquida , Cromatografía en Capa Delgada , Densitometría , Espectrometría de Masa por Ionización de Electrospray , Amoníaco/química , Calibración , Cloroformo/química , Cromatografía Liquida/normas , Cromatografía en Capa Delgada/normas , Densitometría/normas , Estabilidad de Medicamentos , Calor , Humanos , Concentración de Iones de Hidrógeno , Cinética , Metanol/química , Estándares de Referencia , Reproducibilidad de los Resultados , Solventes/química , Espectrometría de Masa por Ionización de Electrospray/normas
17.
J AOAC Int ; 95(5): 1418-24, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23175975

RESUMEN

The purpose of this work was to develop a sensitive stability-indicating TLC-densitometric method for determination of azithromycin (AZ) in the presence of its impurities E, I, and L, and to study the stability of AZ under different stress conditions. The method was developed on TLC aluminum plates precoated with silica gel F254 using the mobile phase methanol-acetone-ammonia 25% (2+13+0.1, v/v/v), which gives compact zones for AZ (Rf= 0.39) and impurities E, I, and L (Rf = 0.54, 0.20, and 0.05, respectively). Densitometric analysis of AZ and its impurities was carried out at 483 nm after spraying with sulfuric acid-ethanol (1 + 4, v/v) and heating at 100 degrees C for 5 min. The linear regression analysis data for the calibration plots showed good linear relationships with r = 0.9941 for AZ, 0.9987 for impurity E, 0.9989 for impurity I, and 0.9984 for impurity L. AZ was subjected to acidic and alkaline hydrolysis, oxidation, and reduction stress. The drug underwent degradation under these conditions. The degradation products were well-resolved from the pure drug, with significantly different Rf values. A plausible degradation pathway of AZ was established by HPLC/electrospray ionization-MS analysis of the products.


Asunto(s)
Azitromicina/química , Cromatografía Líquida de Alta Presión/métodos , Cromatografía en Capa Delgada/métodos , Densitometría/métodos , Espectrometría de Masa por Ionización de Electrospray/métodos , Antibacterianos/química , Química Farmacéutica/métodos , Estabilidad de Medicamentos , Estructura Molecular , Reproducibilidad de los Resultados , Estrés Mecánico
18.
Acta Pol Pharm ; 67(5): 475-9, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20873414

RESUMEN

A simple and rapid HPLC with diode array detection method was developed for the determination of retinyl palmitate present together with other active substances in an ointment. Chromatographic separation was performed on 100 RP-18 Lichrospher column of particle size 5 microm. The mobile phase was methanol:water (98:2, v/v) and flow rate was 2.0 mL/min in isocratic mode. Samples were analyzed for 30 min. Spectophotometric detection was conducted at 325 nm. Under these conditions, the method featured high sensitivity, good precision and comparability of results as proven by the method validation and statistical analysis of the results. The limits of detection and determination were 0.4317 mg/100 mL and 1.3081 mg/100 mL, respectively, recovery values were measured at three levels 80%, 100% and 120% and yielded 101.05%, 101.34% and 100.43%, respectively. The linearity range was checked from 2 mg/100 mL to 10 mg/100 mL. The precision and inter-day precision of the method was expressed by relative standard deviation value and did not exceed 1.68%.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Vitamina A/análogos & derivados , Calibración , Diterpenos , Estabilidad de Medicamentos , Pomadas/análisis , Ésteres de Retinilo , Vitamina A/análisis , Vitamina A/química
19.
J AOAC Int ; 93(3): 792-7, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20629378

RESUMEN

The possibility of radiation sterilization of alprenolol (AL) has been studied. Irradiation of AL in solid form with a 25 kGy beam of electrons caused only an insignificant change in color that became more intense with increasing irradiation dose. Moreover, with increasing dose a decrease in pH, the content of water, and the degree of crystallinity were observed. AL in solid form was radiated with a high-energy electron beam (9.96 MeV) at doses from 25-400 kGy and analyzed by HPTLC using the mobile phase methanol-ammonia 25% (99 + 1, v/v). Densitometric analysis was carried out directly from chromatograms at 270 nm. The applied method was validated and characterized by good precision (RSD = 3.95%); good accuracy (80% level 100.15%, 100% level 99.99%, and 120% level 104.44%); and low LOD (LOD = 0.52 microg/zone and LOQ = 1.55 microg/zone). Chromatograms recorded for samples irradiated at the doses of 25 kGy were unchanged, but at higher doses (100-400 kGy) additional peaks corresponding to the radiodegradation products appeared (Rf = 0.24 and Rf = 0.40). The decrease in the concentration of AL was proportional to the applied radiation dose, and for 400 kGy the concentration of AL was 90.23%. The calculated radiolytic yield of the radiodegradation process was G(-AL) = 7.12 x 10(-7) mol/J.


Asunto(s)
Antagonistas Adrenérgicos beta/química , Alprenolol/química , Cromatografía en Capa Delgada/métodos , Esterilización , Alprenolol/análisis , Alprenolol/efectos de la radiación , Densitometría , Comprimidos
20.
Carbohydr Res ; 343(13): 2336-9, 2008 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-18547550

RESUMEN

Here, we report the crystal structure of D-psicose, C(6)H(12)O(6), one of the rare sugars. The compound crystallizes as the beta-anomer with rarely observed in pyranose carbohydrate structures trans-gauche orientation of the hydroxymethyl group relative to the pyranosyl ring. The crystal system is orthorhombic, space group P2(1)2(1)2(1), Z=4, with cell dimensions a=7.727(2), b=8.672(2), c=11.123(3)A, V=745.3(3)A(3). The pyranosyl ring adopts chair (2)C(5) conformation. The crystal structure at 100(2)K is stabilized by three-dimensional network of O-H...O and C-H...O intermolecular hydrogen bonds.


Asunto(s)
Fructosa/química , Conformación de Carbohidratos , Cristalografía por Rayos X/métodos , Enlace de Hidrógeno , Modelos Químicos , Modelos Moleculares , Modelos Estadísticos , Conformación Molecular , Estructura Molecular , Piranos/química , Temperatura , Difracción de Rayos X
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