Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Phytochemistry ; 225: 114201, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38942106

RESUMO

Seven undescribed 3,4-secolanostane triterpenoids, daldiconoids A-G (1-7), were isolated from the fruiting bodies of Daldinia concentrica. Daldiconoid A (1) was a highly modified 4,6,28,29-tetranorlanostane triterpenoid alkaloid featuring an unusual δ-lactam fused with a flanking cyclopentenone architecture. Their structures were determined by spectroscopic data, NMR calculations coupled with the DP4+ analysis, X-ray single-crystal diffraction, and chemical transformation. The plausible biosynthetic pathway for 1 was proposed. Compounds 1, 2, and 4-6 inhibited the expressions of IL-1ß, IL-6, and TNF-α in lipopolysaccharide stimulated RAW264.7 cells at a concentration of 10 µM. Mechanistically, Compounds 1 and 2 blocked the JAK2/STAT3 signaling pathway induced by lipopolysaccharide.

2.
Int J Pharm ; 628: 122310, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36270552

RESUMO

Multi-component pharmaceutical systems such as cocrystal and salt have gained popularity in academia and industry due to their ability to regulate the poor physicochemical properties of active pharmaceutical ingredients (APIs). However, different crystal states, namely polymorphs are becoming a key factor influencing future clinical drug safety. It remains an under explored field, particularly how to hit the polymorphs of multi-components system quickly and effectively. For the first time, a novel drug-drug salt of lamotrigine (LAM)-tolfenamic acid (TOL) with two polymorphs and two solvates were discovered in this study. Forms I and II exist in rhombohedral and block crystal morphologies, whereas methanol and ethanol solvates are crystallized as rods and flakes, respectively. Further physicochemical properties were characterized and compared between parent compounds and the four crystal forms. The apparent solubilities of the new four crystal forms were higher than TOL but lower than LAM. The intrinsic dissolution rates of all crystal forms at 37.0 °C followed a similar trend, and all crystal forms were non-hygroscopic (<1.0%). Two stable polymorphs provide a new choice for the further formulation development.


Assuntos
Cristalização , Lamotrigina , Solubilidade , Preparações Farmacêuticas
3.
Small ; 18(20): e2200993, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35451111

RESUMO

Local tumor photothermal treatment with the near-infrared light at the second window (NIR-II) is a promising strategy in triggering the in situ tumor vaccination (ISTV) for cancer therapy. However, limited penetration of photothermal agents within tumors seriously limits their spatial effect in generating sufficient tumor-associated antigens, a key factor to the success of ISTV. In this study, a nano-adjuvant system is fabricated based on the NIR-II-absorbable gold nanostars decorated with hyaluronidases and immunostimulatory oligodeoxynucleotides CpG for ISTV. The nano-adjuvant displays a deep tumor penetration capacity via loosening the dense extracellular matrix of tumors. Upon NIR-II light irradiation, the nano-adjuvant significantly inhibits the tumor growth, induces a cascade of immune responses, generates an obvious adaptive immunity against the re-challenged cancers, boosts the abscopal effect, and completely inhibits the pulmonary metastases. The study highlights an advanced nano-adjuvant formulation featuring deep tumor penetration for NIR-II-triggered ISTV.


Assuntos
Ouro , Neoplasias , Linhagem Celular Tumoral , Humanos , Raios Infravermelhos , Neoplasias/terapia , Fototerapia , Vacinação
4.
Life Sci ; 287: 120103, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34743944

RESUMO

BACKGROUND: Heroin is a semi-synthetic opioid that is commonly abused drugs in the world. It can cause hepatic injury and lead to multiple organs dysfunction to its addicts. Only a few reports exist on the metabolic changes and mechanisms in the liver of heroin-addicted mice with hepatic injury. METHODS: Twelve adult male Kunming mice (30-40 g) were divided into two groups randomly. The mice in the heroin-addicted group were injected subcutaneously in the first ten days with an increased dosage of heroin from 10 mg/kg to 55 mg/kg. The dosage was then stabilized at 55 mg/kg for three days. The control group was injected with the same amount of saline in the same manner. The hepatic injury was confirmed through the combination of histopathological observation and aminotransferase (AST) and alanine aminotransferase (ALT) determination. The withdrawal symptoms were recorded and used for assessment of heroin addiction. Eventually, liver metabolic biomarkers of heroin-addicted mice with hepatotoxicity were measured using UHPLC-MS/MS. RESULTS: Biochemical analysis and histopathological observation showed that heroin-addicted mice had a liver injury. The liver metabolites of heroin-addicted mice changed significantly. Metabonomics analysis revealed 41 metabolites in the liver of addicted heroin mice as biomarkers involving 34 metabolic pathways. Among them, glutathione metabolism, taurine and hypotaurine metabolism, vitamin B2 metabolism, riboflavin metabolism, and single-carbon metabolism pathways were markedly dispruted. CONCLUSIONS: Heroin damages the liver and disrupts the liver's metabolic pathways. Glutathione, taurine, riboflavin, 4-pyridoxate, folic acid, and methionine are important metabolic biomarkers, which may be key targets of heroin-induced liver damage. Thus, this study provides an in-depth understanding of the mechanisms of heroin-induced hepatotoxicity and potential biomarkers of liver damage.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Dependência de Heroína/metabolismo , Heroína/toxicidade , Fígado/metabolismo , Metabolômica/métodos , Fenótipo , Animais , Animais não Endogâmicos , Biomarcadores/sangue , Biomarcadores/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/sangue , Doença Hepática Induzida por Substâncias e Drogas/patologia , Dependência de Heroína/sangue , Dependência de Heroína/patologia , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Camundongos
5.
Forensic Sci Int ; 325: 110892, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34273604

RESUMO

BACKGROUND: The concentration levels of major and trace elements are significantly correlated with human health. However, studies profiling major and trace elements among female using methamphetamine are rare. This study aims to investigate the major and trace elements changes and discover elemental biomarkers in plasma of female methamphetamine (METH) addicts in six months' compulsory treatment. METHODS: A total of 60 female METH addicts selected from drug rehabilitation center were randomly divided into three equal groups: (1) Detoxification for one month; (2) Detoxification for three months; (3) Detoxification for six months. Twenty healthy women, without drug abuse history were selected as control group. Four major elements including Na, Mg, K, Ca and twelve trace elements including V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Mo, Sn, Pb were determined using inductively coupled plasma mass spectrometry (ICP-MS). The results were analyzed using One-way Analysis of Variance (ANOVA) and Student-Newman-Keuls (SNK test). Elemental biomarkers were discovered based on orthogonal partial least squares discriminant analysis (OPLS-DA). RESULTS: The four groups used in the study were divided into four significant sections according to scatter plots. The total elemental concentrations of three METH withdrawal groups were increased compared to the control group. Over six months, element contents of the withdrawal groups gradually equaled element contents of the control group in compulsory treatment. The variable importance in the projection values (VIP > 1) of OPLS-DA model and SNK test (p < 0.05) revealed Fe, Cu, Cr and Se as elemental biomarkers. CONCLUSION: Major and trace elements demonstrated significant differences between control group and three METH withdrawal groups. Fe, Cu, Cr and Se are potential elemental biomarkers among METH-abused female groups. Metabolic disorders of major and trace elements exist in the female methamphetamine addicts.


Assuntos
Transtornos Relacionados ao Uso de Anfetaminas/reabilitação , Oligoelementos/sangue , Adulto , Biomarcadores/sangue , Feminino , Humanos , Espectrometria de Massas/métodos , Metanfetamina/efeitos adversos , Centros de Tratamento de Abuso de Substâncias
6.
Adv Healthc Mater ; 10(19): e2100770, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34190424

RESUMO

The antioxidant defense system in malignant cells, which involves antioxidant enzymes and antioxidant molecules, is an innate barrier to photodynamic therapy (PDT). Because of the complexity of the endogenous antioxidant mechanisms of these cells, simply inhibiting individual antioxidant pathways has a limited effect on improving the lethality of ROS. To enhance the efficacy of PDT for tumor treatment, a versatile nanoparticle (NP)-based drug is developed, which the authors call PZB NP, containing the glutathione inhibitor l-buthionine sulfoximine (BSO) and the heme oxygenase 1 (HO-1) inhibitor protoporphyrin zinc(II) (ZnPP) to suppress the innate antioxidant defense system of cancer cells in a two-pronged manner. BSO reduces intracellular glutathione levels to minimize ROS elimination and protein protection during PDT, and ZnPP inhibits the ROS-stimulated upregulation of the antioxidant HO-1, thus preventing ROS removal by cells after PDT. Thus, BSO and ZnPP synergistically suppress the antioxidant defense systems of cancer cells both during and after protoporphyrin-IX-mediated PDT in a two-pronged manner, resulting in tumor cell death through excess oxidative pressure. The results demonstrate that the construction of nanodrugs having dual antioxidation defense suppression properties is a promising route for the development of highly efficient ROS-based therapies.


Assuntos
Glutationa , Fotoquimioterapia , Antioxidantes/farmacologia , Butionina Sulfoximina , Heme Oxigenase-1
7.
Int J Pharm ; 601: 120537, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33781883

RESUMO

Herein, we reported a new bergenin: 4-aminobenzamide (BGN-4AM) cocrystal with significantly enhanced solubility and low hygroscopicity probed from two aspects such as phase solubility diagrams and theoretical calculations. Compared with anhydrous BGN, BGN-4AM solubilities in water and different buffer solutions (pH = 1.2, 4.5, 6.8) increase significantly. It is noted that BGN-4AM solubility in pH = 6.8 buffer solution presents 32.7 times higher than anhydrous BGN. Interestingly, BGN-4AM (0.31 ± 0.07%) showcases lower hygroscopicity than anhydrous BGN (9.31 ± 0.16%). The predicted and experimental solubilities agree with each other when considering solubility product (Ksp) and solution binding constant (K11) in phase solubility diagrams, indicating the solution complexes formation occurs. Further crystal surface-water interactions and Bravais, Friedel, Donnay-Harker (BFDH) analyses based on Density Functional Theory with dispersion correction (DFT-d) methods support the enhanced solubility. The water probe demonstrates an average interaction energy of -6.48 kcal/mol on the 002 plane of BGN-4AM, and only -5.47 kcal/mol on the 011 plane of BGN monohydrate. The lower lattice energy of BGN-4AM guarantees its lower hygroscopicity than BGN monohydrate. BGN-4AM with enhanced solubility and low hygroscopicity can be a potential candidate for further formulation development.


Assuntos
Solubilidade , Benzamidas , Benzopiranos , Cristalização , Molhabilidade , para-Aminobenzoatos
8.
J Nat Prod ; 84(2): 436-443, 2021 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-33560122

RESUMO

A new axial chiral binaphtoquinone, hypocrellone (1), and a new perylenequinone, hypomycin F (2), were isolated from the stromata of Hypocrella bambusae, together with five known compounds, 3-7. The structures of 1 and 2 were assigned by spectroscopic and HRESIMS data analyses. The axial chirality of 1 was determined by electronic circular dichroism data analysis, and the absolute configurations of 2 and 3 were determined by X-ray crystallography. The axial chirality of 7 was determined by UV-induced photooxidation from 4. Compounds 1, 4, and 5 showed inhibitory activity against pseudotyped SARS-CoV-2 infection in 293T-ACE2 cells with IC50 values of 0.17, 0.038, and 0.12 µM. Compounds 4 and 5 were also active against live SARS-CoV-2 infection with EC50 values of 0.22 and 0.21 µM, respectively. Further cell-cell fusion assays, surface plasmon resonance assays, and molecular docking studies revealed that 4 and 5 could bind with the receptor-binding domain of SARS-CoV-2 S protein to prevent its interaction with human angiotensin-converting enzyme II receptor. Our results revealed that 4 and 5 are potential SARS-CoV-2 entry inhibitors.


Assuntos
Hypocreales/química , Naftoquinonas/farmacologia , Perileno/análogos & derivados , Quinonas/farmacologia , SARS-CoV-2/efeitos dos fármacos , Internalização do Vírus/efeitos dos fármacos , Naftoquinonas/química , Perileno/química , Perileno/farmacologia , Quinonas/química , SARS-CoV-2/fisiologia
9.
Toxicol In Vitro ; 62: 104689, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31629902

RESUMO

Titanate nanotubes (TiNTs) have been considered as biocompatible nanomaterials (NMs) for biomedical uses. Hereby, we compared the toxicity of TiNTs and TiO2 nanoparticles (NPs) to human umbilical vein endothelial cells (HUVECs). Our results showed that TiNTs were less effectively internalized into HUVECs compared with TiO2 NPs, but none of the NMs induced cytotoxicity or activation of endoplasmic reticulum (ER) stress biomarkers. In addition, intracellular reactive oxygen species (ROS) was only modestly induced by TiNTs and TiO2 NPs. However, both types of NMs significantly promoted the protein levels of vascular cell adhesion molecule-1 (VCAM-1). TiNTs also promoted the release of soluble (sVCAM-1), but THP-1 monocyte adhesion onto HUVECs was only induced by TiO2 NPs. TiNTs decreased the production of NO, associated with a decrease of protein levels of endothelial NO synthase (eNOS). The transcription factors of eNOS, including kruppel-like factor 2 (KLF2) and KLF4, were more effectively down-regulated by TiNTs compared with TiO2 NPs. In conclusion, our results indicated that TiNTs, albeit not cytotoxic, might impair NO signaling pathway in human endothelial cells leading to the activation of endothelial cells.


Assuntos
Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Nanotubos/toxicidade , Óxido Nítrico/fisiologia , Transdução de Sinais/efeitos dos fármacos , Titânio/toxicidade , Humanos , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/biossíntese , Monócitos/efeitos dos fármacos , Nanoestruturas/toxicidade , Óxido Nítrico Sintase Tipo III/biossíntese , Óxido Nítrico Sintase Tipo III/genética , Espécies Reativas de Oxigênio , Molécula 1 de Adesão de Célula Vascular/biossíntese
10.
Int J Pharm ; 576: 118984, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31870960

RESUMO

Cocrystallization of chlorbipram (ChBP), a novel phosphodiesterase-4 (PDE) inhibitor with water insoluble property developed in our lab, was performed to improve the physicochemical properties and bioavailability in the present study. Three new cocrystals with fumaric aicd (FA), gentisic acid (GA) and salicylic acid (SA) as coformers were synthesized and fully characterized by using the combination of multi-techniques. The cocrystals are phase stable even under high humidity conditions. In vitro study indicates that the solubility of ChBP-GA and ChBP-SA cocrystals increase to 3724.4 ±â€¯58.7, 2897.4 ±â€¯81.9 µg/mL in comparison with ChBP (2561.3 ±â€¯150.4 µg/mL), the intrinsic dissolution rates (IDRs) of ChBP-GA and ChBP-SA cocrystals (721.3 ±â€¯8.0, 614.4 ±â€¯13.2 µg/min/cm2) are both higher than ChBP (537.9 ±â€¯12.0 µg/min/cm2). The blood concentration peak values of ChBP-GA and ChBP-SA cocrystals (165.8 ±â€¯50.9, 105.3 ±â€¯35.6 ng/mL) are both higher than ChBP (51.3 ±â€¯15.1 ng/mL) in in vivo evaluation. It presents the same order in in vitro/vivo study: ChBP-GA > ChBP-SA > ChBP > ChBP-FA. ChBP-FA cocrystal presents a longer elimination half life (t1/2 = 10.0 ±â€¯2.6 h), which makes it a potential candidate for prolonged controlled release formulation. ChBP-GA and ChBP-SA cocrystals both present enhanced solubility and bioavailability in comparison with ChBP, making them a better candidate for the solid dosage formulation development.


Assuntos
Inibidores da Fosfodiesterase 4/química , Inibidores da Fosfodiesterase 4/farmacocinética , Piridazinas/química , Piridazinas/farmacocinética , Animais , Disponibilidade Biológica , Cristalização/métodos , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Fumaratos/química , Fumaratos/farmacocinética , Gentisatos/química , Gentisatos/farmacocinética , Meia-Vida , Masculino , Ratos , Ratos Sprague-Dawley , Ácido Salicílico/química , Ácido Salicílico/farmacocinética , Solubilidade
11.
Ecotoxicol Environ Saf ; 186: 109770, 2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31606643

RESUMO

Cultured human lung epithelial cells, particularly A549 cells, are commonly used as the in vitro model to evaluate the inhalational toxicity of nanoparticles (NPs). However, A549 cells are cancer cells that might not reflect the response of normal tissues to NP exposure. In addition, the possible influence of pulmonary surfactant also should be considered. This study used silica NPs as model NPs, and evaluated the toxicity of silica NPs to both 16HBE human bronchial epithelial cells and A549 adenocarcinomic cells, with or without the presence of pulmonary surfactant component dipalmitoyl phosphatidylcholine (DPPC). We found that silica NPs induced cytotoxicity at the concentration of 128 µg/mL in 16HBE cells but not A5490 cells, and the cytotoxicity of silica NPs to 16HBE cells was inhibited by DPPC. Intracellular reactive oxygen species (ROS) was only induced in 16HBE cells, accompanying with decreased thiol levels. Moreover, 16HBE cells internalized more silica NPs compared with A549 cells, and the internalization was reduced with the presence of DPPC in both types of cells. The retention of ABC transporter substrate Calcein was only significantly induced by silica NPs at high concentrations in 16HBE cells, and was partially reduced due to the presence of DPPC. In addition, ABC transporter inhibitor MK571 increased the toxicity of silica NPs to both types of cells, with 16HBE cells being more sensitive. Our data revealed that the cell types and pulmonary surfactant components could influence the toxicological consequences of silica NPs to human lung cells. Therefore, it is recommended that in vitro studies should carefully select suitable models to evaluate the inhalational toxicity of NPs.


Assuntos
1,2-Dipalmitoilfosfatidilcolina/metabolismo , Células Epiteliais/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Nanopartículas/toxicidade , Surfactantes Pulmonares/metabolismo , Dióxido de Silício/toxicidade , 1,2-Dipalmitoilfosfatidilcolina/análogos & derivados , Células A549 , Sobrevivência Celular/efeitos dos fármacos , Células Epiteliais/metabolismo , Humanos , Pulmão/metabolismo , Espécies Reativas de Oxigênio/metabolismo
12.
Anal Bioanal Chem ; 411(15): 3361-3372, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31119349

RESUMO

Methamphetamine (METH) is one of the most highly addictive illicit drugs abused all over the world. Much evidence indicates that METH abuse leads to major toxicity, medical consequences, and even severe public health consequences. Existing studies usually focus on the pathomechanism of METH-induced toxicity; therefore, data on metabolites and elements correlating with particular toxicity remain scarce. The objective of the present study is to develop appropriate analytical procedures to identify the differential metabolic and elemental biomarkers on METH-induced hepatic injury to rats. The rats were administrated with METH (15 mg/mL/kg, two times per day) via intraperitoneal (i.p.) injections for four consecutive days. The alanine aminotransferase and aspartate aminotransferase activity levels of in the rat serum of the METH group increase significantly compared with those of the control group, suggesting obvious hepatic injury. The results are further confirmed by the histopathological microscopic observation. A total of 18 small molecular metabolites and 19 elements are selected to perform the simultaneous quantification based on the combination of liquid chromatography coupled with tandem mass spectrometry and inductively coupled plasma mass spectrometry. Sample preparation was optimized to cover all the analytes. Both methods are optimized and validated according to developed guidelines such as limits of detection, limits of quantification, linearity, precision, and recovery. All the obtained data are within the satisfactory range. The normalized data were processed according to the partial least squares discrimination analysis (PLS-DA) model. Five differential metabolic and six elemental markers are identified in rat plasma based on the variable importance in projection (VIP) (> 1) and t test results. Overall, the results obtained in this study demonstrate the developed methods are suitable for simultaneous determination of metabolic and elemental markers in the hepatic injury to rats induced by METH. Graphical abstract.


Assuntos
Estimulantes do Sistema Nervoso Central/efeitos adversos , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Metabolômica/métodos , Metanfetamina/efeitos adversos , Espectrometria de Massas em Tandem/métodos , Animais , Biomarcadores/análise , Biomarcadores/sangue , Biomarcadores/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/sangue , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Doença Hepática Induzida por Substâncias e Drogas/patologia , Cromatografia Líquida/métodos , Elementos Químicos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Ratos Sprague-Dawley , Sensibilidade e Especificidade
13.
J Pharm Sci ; 108(10): 3340-3347, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31145922

RESUMO

Polymorphism commonly exists in the preparation of cocrystals and has attracted widespread attention from both the pharmaceutical industry and academia. However, few studies have examined how to discover polymorphic cocrystals and their potential formation mechanism. In this study, we report the novel discovery of salicylic acid: 3-nitrobenzamide (SA-3NBZ) polymorphic cocrystals by thermal methods. The formation mechanism is elucidated based on theoretical calculations. SA-3NBZ polymorphic cocrystals with molar ratio of 1:1 and 2:2 were discovered using the combination of differential scanning calorimetry and hot stage microscopy. Single-crystal X-ray diffraction analysis confirmed this discovery. Density functional theory calculations corrected with dispersion were conducted to illustrate the energetic stabilization of SA polymorphic cocrystals. Compared with the starting materials, formation of the cocrystals at 1:1 and 2:2 present a weak stabilization with overall energy reduction of -0.01 and -0.05 eV/molecule, respectively. The calculated noncovalent interactions index further suggests that intralayer hydrogen bonds and van der Waals forces contribute to these weak interactions. The density functional theory calculations are in good agreement with the X-ray diffraction data. Hence, thermal analysis is a simple and reliable method to discover polymorphic cocrystals.


Assuntos
Cristalização/métodos , Benzamidinas , Varredura Diferencial de Calorimetria/métodos , Cristalografia por Raios X/métodos , Ligação de Hidrogênio , Modelos Moleculares , Difração de Pó/métodos , Ácido Salicílico/química , Solubilidade , Difração de Raios X/métodos
14.
Se Pu ; 36(12): 1290-1296, 2018 Dec 08.
Artigo em Chinês | MEDLINE | ID: mdl-30574708

RESUMO

A chiral separation method was developed for the analysis of methamphetamine (METH) and amphetamine (AM) in hair by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The samples were extracted using methanol by ultrasonication in a high-temperature water bath. The chromatographic separation was performed on a SUPELCO Astec CHIROIOTIC® V2 column with the mobile phase of methanol-20 mmol/L ammonium acetate aqueous solution containing 0.1% (v/v) formic acid (99:1, v/v). All the compounds showed linear relationship in the range of 15-300 ng/mg (r>0.99). The limits of detection (LODs) of METH and AM were 0.1 ng/mg and 0.15 ng/mg, respectively. The limits of quantification (LOQs) of METH and AM were 0.4 ng/mg and 0.5 ng/mg, respectively. The inter-day precisions were all ≤ 6.8%, and the intra-day precisions were all ≤ 11.4%. Fifty drug abuse samples were determined by this method. Up to 70% of the cases were determined as S-(+)-METH and S-(+)-AM, while 18% of the cases were S-(+)-METH, S-(+)-AM, R-(-)-METH and R-(-)-AM. The proposed method is rapid, simple, and provides technical support and a scientific basis for the chiral analysis in actual hair samples for forensic toxicant identification.


Assuntos
Anfetamina/análise , Cabelo/química , Metanfetamina/análise , Cromatografia Líquida de Alta Pressão , Humanos , Limite de Detecção , Estereoisomerismo , Detecção do Abuso de Substâncias , Espectrometria de Massas em Tandem
15.
Int J Pharm ; 509(1-2): 391-399, 2016 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-27282539

RESUMO

Two new 1:1 cocrystals of resveratrol (RES) with 4-aminobenzamide (RES-4ABZ) and isoniazid (RES-ISN) were synthesized by liquid assisted grinding (LAG) and rapid solvent removal (RSR) methods using ethanol as solvent. Their physiochemical properties were characterized using PXRD, DSC, solid state and solution NMR, FT-IR, and HPLC. Pharmaceutically relevant properties, including tabletability, solubility, intrinsic dissolution rate, and hygroscopicity, were evaluated. Temperature-composition phase diagram for RES-ISN cocrystal system was constructed from DSC data. Both cocrystals show higher solubility than resveratrol over a broad range of pH. They are phase stable and non-hygroscopic even under high humidity conditions. Importantly, both cocrystals exhibit improved solubility and tabletability compared with RES, which make them more suitable candidates for tablet formulation development.


Assuntos
Estilbenos/química , Comprimidos/química , Benzamidas/química , Varredura Diferencial de Calorimetria/métodos , Química Farmacêutica/métodos , Cristalização/métodos , Espectroscopia de Ressonância Magnética/métodos , Modelos Moleculares , Difração de Pó/métodos , Resveratrol , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Temperatura , Difração de Raios X/métodos , para-Aminobenzoatos/química
16.
Pharm Res ; 33(4): 1030-9, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26744333

RESUMO

PURPOSE: The purpose of this work was to develop thermal methods to identify cocrystal systems with stoichiometric diversity. METHODS: Differential scanning calorimetry (DSC) and hot stage microscopy (HSM) have been applied to study the stoichiometric diversity phenomenon on cocrystal systems of the model compound salicylic acid (SA) with different coformers (CCFs). The DSC method was particularly useful in the identification of cocrystal re-crystallization, especially to improve the temperature resolution using a slower heating rate. HSM was implemented as a complementary protocol to confirm the DSC results. The crystal structures were elucidated by single-crystal X-ray diffraction (SXRD). RESULTS: Two new cocrystal systems consisting of salicylic acid-benzamide (SA-BZD, 1:1, 1:2) and salicylic acid-isonicotinamide (SA-ISN, 1:1, 2:1) have been identified in the present work. The chemical structures of the newly discovered cocrystals SA-BZD (1:2) and SA-ISN (2:1) have been elucidated using X-ray single crystal and powder diffraction methods. CONCLUSIONS: The developed thermal methods could rapidly identify cocrystal systems with stoichiometric diversity, with the potential to discover new pharmaceutical cocrystals in the future.


Assuntos
Anti-Infecciosos/química , Benzamidas/química , Niacinamida/química , Ácido Salicílico/química , Varredura Diferencial de Calorimetria , Cristalização , Cristalografia por Raios X , Modelos Moleculares , Difração de Pó , Temperatura
17.
J Microencapsul ; 33(1): 43-52, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26626402

RESUMO

CONTEXT: PLGA nanoparticles have been widely utilised to encapsulate lipophilic drugs for sustained release. OBJECTIVE: This study was to enhance encapsulation efficiency and drug loading for the poorly lipophilic drug dihydroartemisinin (DHA) in PLGA nanoparticles, where amphiphilic phospholipid was employed as the intermediate. MATERIALS AND METHODS: DHA-phospholipid complex formulation was optimised using the response surface method. DHA-phospholipid complex-nanoparticles (DHA-PLC-NPs) were prepared using the solvent evaporation method. RESULTS: The particle size, zeta potential, entrapment efficiency and drug loading of the nanoparticles were 265.3 ± 7.9 nm, -21.4 ± 6.3 mV, 74.2 ± 6.5% and 2.80 ± 0.35%, respectively. Compared with the rapidly released free form, DHA underwent sustained release from the nanoparticles. DHA-PLC-NPs presented stronger cell proliferative inhibition than DHA treatment alone and apoptosis was obviously induced after DHA-PLC-NPs treatment. CONCLUSION: Phospholipid complexes are useful intermediate to improve the lipophilicity of drugs, the interaction with the hydrophobic core of PLGA and the encapsulation efficiency of poorly lipophilic drugs in polymeric nanoparticles.


Assuntos
Artemisininas , Portadores de Fármacos , Ácido Láctico , Nanopartículas/química , Fosfolipídeos , Ácido Poliglicólico , Artemisininas/química , Artemisininas/farmacocinética , Artemisininas/farmacologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/farmacologia , Células Hep G2 , Humanos , Ácido Láctico/química , Ácido Láctico/farmacocinética , Ácido Láctico/farmacologia , Nanopartículas/ultraestrutura , Fosfolipídeos/química , Fosfolipídeos/farmacocinética , Fosfolipídeos/farmacologia , Ácido Poliglicólico/química , Ácido Poliglicólico/farmacocinética , Ácido Poliglicólico/farmacologia , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
18.
Nat Prod Res ; 29(2): 185-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25277166

RESUMO

An efficient, feasible enrichment and separation method of epimedins A, B, C and icariin from Herba Epimedii was developed by the combination of microwave-assisted extraction, macroporous resins and preparative HPLC. WDX-5 macroporous resin shows better recoveries at 96.2%, 97.0%, 98.2% and 97.1% for epimedins A, B, C and icariin than other macroporous resins used in the experiments. As a result, epimedins A (5.1 mg), B (15.3 mg), C (7.6 mg) and icariin (14.3 mg) were obtained from 6.0 g crude Herba Epimedii with the recoveries at 70.8%, 68.9%, 66.7% and 95.3%, respectively. The method developed in this study may provide scientific references for the enrichment and separation of flavonoids from Herba Epimedii.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Epimedium/química , Flavonoides/isolamento & purificação , Estrutura Molecular
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...