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1.
AAPS PharmSciTech ; 22(2): 56, 2021 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-33486601

RESUMO

Compared with single micelle, the new PTX-HS15/T80 mixed micelle system (PTX-HS15/T80 MMs) had achieved better results in solubilization, stability, and sensitization before. Therefore, we intend to further verify the potential advantages of the mixed micelle delivery system through in vitro cytotoxicity test and animal test to understand the anticancer effect and in vivo pharmaceutical behavior of the system. In vitro cytotoxicity test showed that the new PTX-HS15/T80 MMs had a stronger ability to inhibit the proliferation of cancer cells. The results of in vivo pharmacokinetics showed that the micelle had shorter half-life, higher clearance rate, and lower blood concentration and had good blood clearance characteristics. The results of in vivo tissue distribution showed that, compared with the single micelle Taxol®, the new PTX-HS15/T80 MMs had good distribution characteristics in the lung (AUC (lung 0-4 H) increased about 26%) and low concentration in the heart (AUC (Heart 0-4 H) decreased about 10%). Paclitaxel was mainly metabolized through the liver and kidney. The above results suggested that the new PTX-HS15/T80 MMs may have a certain therapeutic potential against lung cancer and reduce the toxic and side effects. In general, the mixed micelle delivery system was not only simple and cheap to prepare but also had certain advantages in vitro and in vivo, indicating that the combination of surfactants provides a good choice for solving the problem of insoluble drug delivery.


Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Sistemas de Liberação de Medicamentos , Micelas , Paclitaxel/administração & dosagem , Polietilenoglicóis/química , Polissorbatos/química , Ácidos Esteáricos/química , Animais , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos/métodos , Feminino , Masculino , Paclitaxel/farmacocinética , Paclitaxel/farmacologia , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
2.
Food Chem ; 347: 129070, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33482483

RESUMO

Interesterification is widely employed as an effective technique to modify oils and fats. This study utilizes palm-based oil (palm olein: palm kernel oil: palm stearin, 5:3:2, w/w/w) as the raw material for the interesterification process performed in a pilot-scale packed bed reactor. Enzymatic interesterification (EIE) was catalyzed by Lipozyme TL IM (813.0 g) at 60℃ with reaction flow rate of 100 mL/min. Chemical interesterification (CIE) was catalyzed using sodium methoxide (0.3 wt%) as catalyst at 105 °C for 30 min. The results showed that the EIE fats had lower solid fat content tendency compared to that of CIE fats. The crystallization onset temperature was higher in EIE fats (23.09℃) compared to that of CIE (19.08℃). The results were consistent with the crystallization kinetics whereby the Avrami K constants of EIE fats were higher than that of CIE fats at various temperatures, indicating rapid crystallization and instant nucleation. Linear growth mechanism was dominant and the crystals formed were smaller in size as observed using polarized light microscope. The interesterified fats exhibited the presence of ß and ß'-crystals. While most of the tocopherol content was retained after EIE (386.18 ug/g), the molecular distillation process reduced the tocopherol concentration (110.01 ug/g) which consequently affected the oxidative stability. The findings in this work contribute to the fundamental understanding on the differences between CIE and EIE fats and provides data to support the preparation of modified fats via EIE that shows great potential as a controllable technique for industrialization.


Assuntos
Ácidos Graxos/química , Óleo de Palmeira/química , Biocatálise , Cristalização , Esterificação , Cinética , Lipase/metabolismo , Ácido Oleico/química , Oxirredução , Reologia , Ácidos Esteáricos/química , Termodinâmica
3.
ACS Appl Mater Interfaces ; 13(3): 4740-4749, 2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33370088

RESUMO

Superhydrophobic conductive materials have received a great amount of interest due to their wide applications in oil-water separation, electrically driven smart surface, electromagnetic shielding, and body motion detection. Herein, a highly conductive superhydrophobic cotton cloth is prepared by a facile method. A layer of polydopamine/reduced graphene oxide (PDA/rGO) was first coated on the cotton fabric, and then copper nanoparticles were in situ grown on the prepared surface. After further modification with stearic acid (STA), the wettability of the cotton surface changed from superhydrophilic to superhydrophobic (water contact angle (WCA) = 153°). The electrical conductivity of the PDA/rGO/Cu/STA cotton is as high as 6769 S·m-1, while the stearic acid effectively protects Cu NPs from oxidation. As a result, the superhydrophobic PDA/rGO/Cu/STA cotton has shown excellent electrical stability and can be used in detecting human motions in both ambient and underwater conditions. The sensor can recognize human motion from air into water and other underwater activities (e.g., underwater bending, stretching, and ultrasound). This multifunctional cotton device can be used as an ideal sensor for underwater intelligent devices and provides a basis for further research.


Assuntos
Técnicas Biossensoriais/instrumentação , Fibra de Algodão/análise , Grafite/química , Indóis/química , Polímeros/química , Dispositivos Eletrônicos Vestíveis , Técnicas Biossensoriais/métodos , Condutividade Elétrica , Desenho de Equipamento , Humanos , Interações Hidrofóbicas e Hidrofílicas , Movimento (Física) , Oxirredução , Ácidos Esteáricos/química , Água/química , Molhabilidade
4.
Food Chem ; 334: 127585, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32711275

RESUMO

Glycerol monosterate (GMS) and stearic acid (SA) share a similar carbon chain structure while SA has a carboxyl head group and GMS has two free hydroxyl groups. The current research focuses on the relationship between GMS and SA chemical structure, nano and mesoscale crystal structure, and the oleogel macroscopic characteristics. Molecular analysis revealed the formation of different types of hydrogen bonds, which disappear upon temperature increase at different temperatures. Nano-structural analysis exhibited tight and ordered lamellar structures for SA compared with loosely packed short lamellar structures in GMS oleogel, presumably due to its larger hydrophilic head group. Microstructure imaging revealed ordered anisotropically orientated needle-like crystals in SA and isotopically ordered braid-like crystals in GMS oleogels. Mechanical analysis revealed that gel strength is enhanced when crystal structure is isotropically oriented, similar behavior seen is composite materials, where the structuring agent crystals behave like a reinforcing agent within the oil matrix.


Assuntos
Ácidos Esteáricos/química , Ligação de Hidrogênio , Nanoestruturas/química , Compostos Orgânicos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termogravimetria , Difração de Raios X
5.
Food Chem ; 339: 127808, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32829241

RESUMO

This paper reports an experimental study of the formation and properties of dark chocolate prepared using novel CB alternative fats (CBAs): symmetric (OSatO) and asymmetric (SatSatO) mixed-acid triacylglycerols (TAGs), in which Sat and O represent saturated fatty acids (stearic:S + palmitic:P) and oleic acid moieties, respectively. It was found that the ternary fat mixtures of CB/SatSatO/OSatO with a ratio of CB/(SatSatO + OSatO) of 1:1 formed the most stable ß-form of the double chain length (DCL) structure (ß-2), which revealed sufficient hardness and sharp melting profiles around body temperature without tempering processes. Fat bloom formation was not observed in dark chocolate with CBAs at ratios of CB/SatSatO/OSatO of 50/20/30-50/0/50 during the one-year storage test at temperatures between 15 °C and 30 °C. Overall, the present study has shown that fat mixtures made of CB/SatSatO/OSatO, which are rich in oleic acid moieties, can be employed as a cocoa butter equivalent (CBE) fat without tempering procedures.


Assuntos
Chocolate , Gorduras na Dieta , Triglicerídeos/química , Varredura Diferencial de Calorimetria , Cristalização , Ácidos Graxos/química , Ácido Oleico/química , Ácido Palmítico/química , Ácidos Esteáricos/química
6.
J Oleo Sci ; 69(11): 1403-1409, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33055438

RESUMO

We studied the structures and properties of gel samples prepared by mixtures of N-[3-(dimethylamino)propyl]docosanamide (APA-22) acid salt (APA-22 L-lactic acid), 1-octadecanol (C18OH), and water. The gel samples prepared at the mole ratios [APA-22 L-lactic acid]:C18OH = 1:3, 1:4, and 1:5 yielded two phases; one being the α-gel (α-form hydrated crystal) phase, incorporating a significant quantity of water between lamellar bilayers, and the other being the excess water phase. The lamellar d-spacing remained practically unaltered at these mole ratios, thus maintaining the quantity of water incorporated between the lamellar bilayers relatively constant. Starting at 30°C, the gel samples transformed into a lamellar liquid crystal phase at high temperatures (85°C) and a ß-gel phase at low temperatures (5°C). Interestingly, following dilution by pure water, the viscosity of the gel samples decreased with increasing C18OH content. We expect that the viscosity change affects the performance of the gel samples as hair conditioners.


Assuntos
Amidas/química , Tensoativos/química , Cristalização , Géis , Preparações para Cabelo , Ácido Láctico/química , Bicamadas Lipídicas/química , Ácidos Esteáricos/química , Temperatura , Viscosidade , Água/química
7.
J Oleo Sci ; 69(9): 1043-1049, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32788510

RESUMO

The 2-ethylhexyl stearate is used as a bio-lubricant in various cosmetic products. The present study is focused on the biocatalyzed esterification of 2-ethylhexanol and stearic acid to form 2-ethylhexyl stearate catalyzed by Fermase CALB 10000 in the presence of ultrasound treatment. The maximum conversion (95.87%) was obtained at molar ratio of 2-ethylhexanol to stearic acid 2:1, enzyme amount of 2 % (w/w), power 80 W, duty cycle 50 % and temperature 50°C in comparatively short reaction time (3 h) in the presence of Fermase as a catalyst. At optimum conditions, it is observed that in the presence of ultrasound; the reaction time minimizes up to 4 h as compared to mechanical stirring method (7 h). The physiochemical properties for the 2-ethylhexyl palmitate were also evaluated.


Assuntos
Hexanóis/química , Estearatos/síntese química , Ondas Ultrassônicas , Biocatálise , Fenômenos Químicos , Enzimas Imobilizadas/química , Esterificação , Estearatos/química , Ácidos Esteáricos/química , Temperatura , Fatores de Tempo
8.
J Oleo Sci ; 69(9): 1139-1143, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32788524

RESUMO

We compared the cytotoxic effects and tumor necrosis factor-α (TNF-α) production induced by 13 trans-octadecenoic acid positional isomers (trans-4-C18:1 to trans-16-C18:1) in RAW264.7 cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and enzyme-linked immunosorbent assay, respectively. No significant differences were observed in the cytotoxic effects among the 13 trans-C18:1 positional isomers and control on RAW264.7 cells. TNF-α production significantly decreased by treatment of trans-4-C18:1 as compared to control, but no significant differences in TNF-α production were observed among other trans-C18:1 positional isomers and control. These results suggest that the double bond position in trans-C18:1 may affect TNF-α production in cells.


Assuntos
Células RAW 264.7/metabolismo , Ácidos Esteáricos/toxicidade , Fator de Necrose Tumoral alfa/metabolismo , Animais , Isomerismo , Camundongos , Ácidos Esteáricos/química , Relação Estrutura-Atividade
9.
Arch Biochem Biophys ; 692: 108532, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32795451

RESUMO

Fatty acid uptake and accumulation in lipid droplets are essential processes of lipid metabolism. Oocyte in vitro culture in media enriched with fatty acid is used to modify the lipid content and composition, aiming to study the consequences of obesity and enhance cell cryotolerance. We applied Raman spectroscopy and deuterium labeling approach to quantify stearic acid uptake and investigate its incorporation within oocytes. Our data suggest that deuterium labeling does not affect oocyte maturation rates. The efficiency of deuterated stearic acid (dSA) uptake was shown to decrease with the increase of its concentration in culture medium and the duration of in vitro culture. The molar ratio between dSA and bovine serum albumin has no significant effect on the dSA uptake for 200 µM but modifies concentration dependence of the lipid uptake. dSA accumulates in all the lipid droplets inside oocytes. Different lipid droplets within the same oocyte exhibit different concentrations of dSA. The scatter in the dSA concentration in lipid droplets decreases with the culture time. Using dSA as an example, we provide a comprehensive description of how fatty acid concentration, its molar ratio versus bovine serum albumin, and culture time affect the uptake of the fatty acids in oocytes. Raman microspectroscopy of deuterium-labeled fatty acids is a nondestructive tool providing information about fatty acid uptake and heterogeneity of their accumulation between lipid droplets within the single oocyte.


Assuntos
Deutério , Gotículas Lipídicas/metabolismo , Oócitos/metabolismo , Ácidos Esteáricos , Animais , Gatos , Deutério/química , Deutério/farmacocinética , Deutério/farmacologia , Feminino , Marcação por Isótopo , Oócitos/citologia , Ácidos Esteáricos/química , Ácidos Esteáricos/farmacocinética , Ácidos Esteáricos/farmacologia
10.
J Chromatogr A ; 1624: 461259, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32540084

RESUMO

An analytical procedure for the rapid and selective derivatization of free fatty acids into methyl esters directly in plasma without transmethylation of lipid-bound fatty acids was developed for their analysis by gas chromatography-mass spectrometry. The methyl esters of free fatty acids were obtained by reaction with methyl iodide in the solution of dipolar aprotic solvents and in the presence of solid bases. The mechanism of the methylation reaction with these reagents was investigated. Optimal conditions for the selective methylation of free fatty acids were established using different dipolar aprotic solvents and different solid bases. The possible transmethylation of covalently bonded fatty acids from plasma lipids has been investigated under different experimental conditions in order to be avoided. Total methylation of free fatty acids was achieved in 1 min at room temperature using methyl iodide and anhydrous potassium carbonate or sodium carbonate in dimethyl sulfoxide. Under these conditions, transmethylation of lipid-bound fatty acids was avoided. The methyl esters can be injected directly from the reaction solvents. A plasma volume of 50 µL was used without special purification. The detection limits were around 0.1 ng/µL. The proposed method avoids the drawbacks of the previous methods used for the one-step analysis of individual free fatty acids in human plasma.


Assuntos
Ácidos Graxos não Esterificados/sangue , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Limite de Detecção , Metilação , Reprodutibilidade dos Testes , Solventes/química , Ácidos Esteáricos/química
11.
Ceska Slov Farm ; 69(1): 43-47, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32460509

RESUMO

To identify possible interactions of components in dosage forms, studies are usually carried out at the stage of pharmaceutical development. Such studies can predict compatibility of active pharmaceutical ingredients and excipients in order to optimize drug formulation and certain parameters of technological process. Compatibility of some components of a newly developed neuroprotective medicinal product Neuronucleos, namely, thioctic acid, pyridoxine hydrochloride, magnesium stearate and magnesium lactate, was studied by means of differential scanning calorimetry (DSC) and Fourier-transform infrared spectroscopy (FTIR). No interactions were observed between thioctic acid and pyridoxine hydrochloride. Formation of an intermolecular complex between thioctic acid and magnesium stearate was established, in which this acid substitutes the crystalline water of magnesium stearate. No significant interactions were found for magnesium lactate with thioctic acid or magnesium stearate. Thus, pharmaceutical compatibility of the most of the tested Neuronucleos components was studied and established, with the only exception (thioctic acid with magnesium stearate). Moreover, the present study provides valuable information about thermal effects in a certain temperature range, which is important for setting the technological process parameters.


Assuntos
Compostos de Magnésio/química , Piridoxina/química , Ácidos Esteáricos/química , Ácido Tióctico/química , Excipientes
12.
Pharm Res ; 37(6): 92, 2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32394200

RESUMO

PURPOSE: The aim of the study was to evaluate organogel nanoparticles as a lipophilic vehicle to increase the oral bioavailability of poorly soluble compounds. Efavirenz (EFV), a Biopharmaceutical Classification System (BCS) Class II, was used as drug model. METHODS: Organogel nanoparticles loaded with EFV were formulated with sunflower oil, 12-hydroxystearic acid (HSA) and polyvinyl alcohol (PVA). Various parameters have been investigated in the current study such as (i) the release profile of organogel assessed by USP 4 cell flow dialysis, (ii) the impact of organogel on intestinal absorption, using Caco-2 cells as in vitro model and jejunum segments as ex vivo assay and (iii) the bioavailability of organogel following oral pharmacokinetic study. RESULTS: 250-300 nm spherical particles with a final concentration of 4.75 mg/mL drug loading were obtained, corresponding to a thousand fold increase in EFV solubility, combined to a very high encapsulation efficiency (>99.8%). Due to rapid diffusion, drug was immediately released from the nanoparticles. The biopharmaceutical evaluation on ex vivo jejunum segments demonstrated an increased absorption of EFV from organogel nanoparticles compare to a native EFV suspension. In vitro assays combining Caco-2 cell cultures with TEM and confocal microscopy demonstrated passive diffusion, while paracellular integrity and endocytosis activity remain expelled. Oral pharmacokinetics of EFV organogel nanoparticles improve oral bioavailability (Fr: 249%) and quick absorption compared to EFV suspension. CONCLUSION: Organogel nanoparticles increase the bioavailability of BCS Class II drugs. The main phenomena is simply oil transfer from the gelled particles through the cell membrane.


Assuntos
Benzoxazinas/química , Portadores de Fármacos/química , Géis/química , Nanocápsulas/química , Álcool de Polivinil/química , Ácidos Esteáricos/química , Óleo de Girassol/química , Alquinos , Animais , Benzoxazinas/administração & dosagem , Benzoxazinas/farmacocinética , Disponibilidade Biológica , Células CACO-2 , Permeabilidade da Membrana Celular , Sobrevivência Celular/efeitos dos fármacos , Ciclopropanos , Difusão , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos , Excipientes/química , Humanos , Absorção Intestinal , Masculino , Solubilidade , Suspensões/química , Distribuição Tecidual
13.
Food Chem ; 324: 126801, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32353654

RESUMO

Structuring of vegetable oils has potential application in food, pharmaceutical and cosmetic products. In this study, structuring effects of stearic acid derivatives on sunflower seed oil were systematically investigated by experimental and molecular simulation methods. Stearic acid (SA), 12-hydroxy stearic acid (HSA) and 2-hydroxyethyl stearate (HES) were able to structure sunflower seed oil, among which the structuring ability of HES was reported for the first time. The oleogel formed with HSA exhibited good mechanical properties (such as hardness, fracturability, adhesiveness, chewiness and storage modulus), which coincided with its highest solid fat content and degree of crystallinity. Oleogels containing SA and HES showed similar mechanical properties. Both the molecular dynamics (MD) simulation and independent gradient model (IGM) confirmed that the HSA dimer possessed the strongest interaction during the self-assembly process while the dimers of HES and SA had similar interactions, which could explain their structuring performance.


Assuntos
Estearatos/química , Ácidos Esteáricos/química , Óleo de Girassol/química , Armazenamento de Alimentos , Dureza , Modelos Moleculares , Simulação de Dinâmica Molecular , Compostos Orgânicos/química , Temperatura
14.
Molecules ; 25(4)2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32074951

RESUMO

The use of natural products as chemotherapeutic agents is well established; however, many of these are associated with undesirable side effects, including high toxicity and instability. Furthermore, the development of drug resistant cancers makes the search for new anticancer lead compounds a priority. In this study, the extraction of an Ircinia sp. sponge resulted in the isolation of an inseparable mixture of (7E,12E,20Z)-variabilin (1) and (7E,12Z,20Z)-variabilin (2) and structural assignment was established using standard 1D and 2D NMR experiments. The cytotoxic activity of the compound against three solid tumour cell lines displayed moderate anti-cancer activity through apoptosis, together with a general lack of selectivity among the cancer cell lines studied. Structural assignment and cytotoxic evaluation of variabilin was complicated and further aggravated by its inherent instability. Variabilin was therefore incorporated into solid lipid nanoparticles (SLNs) and the stability and cytotoxic activity evaluated. Encapsulation of variabilin into SLNs led to a marked improvement in stability of the natural product coupled with enhanced cytotoxic activity, particularly against the prostate (PC-3) cancer cell line, with IC50 values of 87.74 µM vs. 8.94 µM for the variabilin alone and Var-SLN, respectively. Both variabilin and Var-SLN revealed comparable activity to Ceramide against the MCF-7 breast cancer cell line, revealing IC50 values of 34.8, 38.1 and 33.6 µM for variabilin, Var-SLN and Ceramide, respectively. These samples revealed no activity (>100 µM for all) against HT-29 (colon) cell lines and MCF-12 (normal breast) cell lines. Var-SLNs induced 47, 48 and 59% of apoptosis in HT-29, MCF-7 and PC-3 cells, respectively, while variabilin alone revealed 38, 29 and 29% apoptotic cells for HT-29, MCF-7 and PC-3 cell lines, respectively. The encapsulation of natural products into SLNs may provide a promising approach to overcome some of the issues hindering the development of new anticancer drugs from natural products.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Proteínas/farmacologia , Ácidos Esteáricos/farmacologia , Antineoplásicos/química , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Lipídeos/química , Lipídeos/farmacologia , Células MCF-7 , Nanopartículas/química , Proteínas/química , Ácidos Esteáricos/química
15.
Artigo em Inglês | MEDLINE | ID: mdl-31963838

RESUMO

The hydrophobicity and anti-fouling properties of materials have important application value in industrial and agricultural production and people's daily life. To study the relationship between the unit width L0 of the parabolic hydrophobic material and the hydrophobicity and anti-fouling properties, the rough surface structure of the parabolic with different widths was prepared by grinding with different SiC sandpapers, and further, to obtain hydrophobic materials through chemical oxidation and chemical etching, and modification with stearic acid (SA). The morphology, surface wetting and anti-fouling properties of the modified materials were characterized by SEM and contact angle measurement. The oil-water separation performance and self-cleaning performance of the materials were explored. The surface of the modified copper sheet forms a rough structure similar to a paraboloid. When ground with 1500 grit SiC sandpaper, it is more conducive to increase the hydrophobicity of the copper sheet surface and increase the contact angle of water droplets on the copper surface. Additionally, the self-cleaning and anti-fouling experiments showed that as L0 decreases, copper sheets were less able to stick to foreign things such as soil, and the better the self-cleaning and anti-fouling performance was. Based on the oil-water separation experiment of copper mesh, the lower L0 has a higher oil-water separation efficiency. The results showed that material with parabolic morphology has great self-cleaning, anti-fouling, and oil-water separation performance. The smaller the L0 was, the larger the contact angle and the better hydrophobic performance and self-cleaning performance were.


Assuntos
Cobre/química , Interações Hidrofóbicas e Hidrofílicas , Teste de Materiais , Óleos/química , Oxirredução , Ácidos Esteáricos/química , Água/química , Molhabilidade
16.
Int J Pharm ; 576: 119027, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31953090

RESUMO

We developed a safe and efficacious drug delivery system for treatment of brain diseases. A novel in-situ gel system was prepared using soybean oil, stearic acid and N-methyl-2-pyrrolidinone (NMP) (10:1:3, v/w/v). This system had low viscosity as a sol in vitro and turned into a solid or semi-solid gel in situ after administration. The poorly water-soluble drug flunarizine hydrochloride (FNZ) was incorporated into this "organogel" system. Organogel-FNZ was characterized by light microscopy, differential scanning calorimetry (DSC) and rheology. Drug release in vitro was investigated. The initial "burst" effect did not occur in organogel-FNZ, which is different from other gels formed in situ. Pharmacokinetic studies were undertaken in rats using gel administration (14 mg kg-1), intravenous administration (5 mg kg-1) and administration using drops (14 mg kg-1). Organogel-FNZ could reduce the clearance rate and prolong the duration of action, in the plasma and brain tissues of rats. The peak serum concentration, area under the curve and absolute bioavailability of the organogel-FNZ group were higher than those of the intraocular- drops group. Organogel-FNZ is a promising drug-delivery system for treatment of brain diseases by intraocular administration.


Assuntos
Portadores de Fármacos , Flunarizina/administração & dosagem , Pirrolidinonas/química , Óleo de Soja/química , Ácidos Esteáricos/química , Administração Intravenosa , Administração Oftálmica , Animais , Disponibilidade Biológica , Composição de Medicamentos , Liberação Controlada de Fármacos , Flunarizina/química , Flunarizina/farmacocinética , Géis , Masculino , Soluções Oftálmicas , Coelhos , Ratos Sprague-Dawley , Viscosidade
17.
Int J Pharm ; 576: 118994, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31893543

RESUMO

Lubricants are important for both preserving the tooling of high-speed tablet presses and attaining quality tablets. Magnesium stearate (MgSt) is most commonly used due to its superior lubrication efficiency; however, it can lead to negative effects on tabletability and dissolution. In this study, we have systematically evaluated two poloxamers, P188 and P407, for their suitability as alternative tablet lubricants. For two excipients with different mechanical properties, i.e., microcrystalline cellulose and lactose, both poloxamers exhibit acceptable lubrication efficiency without negatively impacting tabletability. Compared to 1% MgSt, the performance of 2% of both poloxamers in an experimental tablet formulation of ritonavir led to better lubrication, higher tabletability, and enhanced in vitro drug release. Thus, the use of P188 and P407 as alternative tablet lubricants deserves further evaluations.


Assuntos
Celulose/química , Excipientes/química , Lactose/química , Lubrificantes/química , Poloxâmero/química , Ritonavir/química , Administração Oral , Composição de Medicamentos , Liberação Controlada de Fármacos , Cinética , Ritonavir/administração & dosagem , Solubilidade , Ácidos Esteáricos/química , Comprimidos
18.
Mater Sci Eng C Mater Biol Appl ; 108: 110408, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31924047

RESUMO

With the increasing requirement of bone repair materials, hydroxyapatite (HA) has been paid widely attention to investigation because of its good bioactivity and osteoconductivity. The structure of HA is a vital factor to expand its application in the field of hard tissue therapy. Thus, many strategies have been utilized in fabricating one-dimensional (1D) and three-dimensional (3D) nanostructured HA. In this paper, we successful synthesize HA with 1D nanofibers and 3D nanostructured microspheres using stearic acid as a template and different phosphates as phosphorus sources under the same synthetic system. The morphology of HA changes from nanofibers with high flexibility to nanostructured microspheres with good sphericity under the synergistic effect of stearic acid and various phosphates. The HA nanofibers and microspheres are promising for applications in biomedical fields. Base on characterization results, the formation mechanisms of HA nanofibers and HA microspheres self-assembled by nanorods are proposed. Furthermore, the HA morphology transition from nanofibers to nanostructured microspheres may be attributed to the formation of polyphosphate-induced water-in-oil microemulsion system in the synthesis process. The finding may provide a new direction to control HA morphology from 1D nanofibers to 3D microspheres based on previous strategies.


Assuntos
Durapatita/química , Nanofibras/química , Nanoestruturas/química , Microesferas , Ácidos Esteáricos/química , Difração de Raios X
19.
Drug Dev Ind Pharm ; 46(1): 159-171, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31894713

RESUMO

Objective: The main scope of present investigation was preparation and physicochemical characterization of solid lipid nanoparticles (SLNs) loaded by α-tocopherol acetate (ATA).Methods: ATA-loaded nanoparticles were prepared by solvent injection-homogenization technique using stearic acid as the solid lipid, phosphatidylcholine as the stabilizer and finally coated by chitosan with the aim of increasing z-potential and also having a more stable nano-formulation. Then, characterization of SLNs has been conducted using dynamic light scattering (DLS), zeta potential measurement, Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC).Results: Nanoparticles with average sizes of 175 ± 15 nm and zeta potential of +35 ± 2.5 mV were obtained. An excellent drug entrapment efficiency of 90.58 ± 1.38% was obtained with a no-burst slow release up to about 10 days tested. The final plateau of release of ATA from nanoparticulate system within 216 h was 61.13 ± 0.13% which was approached in about 150 h. Physical stability studies showed that the ATA nano-formulation remained stable with slight increase in mean particle size and polydispersity index over a 3-month period in refrigerated temperature. Considering both FTIR and DSC analysis, it can be concluded that there is no new band formation between materials and ATA in our nano-formulation. Particle sizes obtained using AFM images are in a good agreement to those established from the DLS analysis.Conclusion: These data showed a promising delivery system for vitamin E based on SLN platform.


Assuntos
Portadores de Fármacos/química , Lipídeos/química , Nanopartículas , alfa-Tocoferol/administração & dosagem , Química Farmacêutica , Quitosana/química , Preparações de Ação Retardada , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Tamanho da Partícula , Fosfatidilcolinas/química , Refrigeração , Ácidos Esteáricos/química , alfa-Tocoferol/química
20.
Int J Pharm ; 575: 118936, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31846729

RESUMO

A numerical study of the tableting process using a finite element method (FEM) is important to quantitatively understand the structural change inside the tablet and the mechanism of tableting failures such as capping, picking, lamination, and sticking. In the pharmaceutical field, the Drucker-Prager Cap (DPC) model is used most widely to demonstrate the mechanical behavior of the powder during tableting. The DPC model, however, cannot consider compaction speed, although the compaction speed has a large impact on the tablet strength and tableting failures. In the present study, a combined novel model using both the DPC and Perzyna models, which incorporates a visco-plastic behavior considering the compression speed, was proposed and numerical simulation was conducted. Cellulose, lactose, and acetaminophen were selected as model powders. The DPC-Perzyna model parameters were determined from experimental compaction tests, unconfined compression tests, and tension tests. The calculated loading curves agreed with the experimental data under different compaction speeds, in addition the high compression speed resulted in less plastic deformation and much residual stress. It was demonstrated that the DPC-Perzyna model proposed in the present study was useful to analyze the tableting process when considering compression speed.


Assuntos
Modelos Teóricos , Comprimidos , Tecnologia Farmacêutica , Acetaminofen/química , Celulose/química , Simulação por Computador , Excipientes/química , Lactose/química , Pressão , Ácidos Esteáricos/química
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