Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Front Bioeng Biotechnol ; 11: 1115254, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37600314

RESUMO

Perfluorocarbon (PFC) are biocompatible compounds, chemically and biologically inert, and lacks toxicity as oxygen carriers. PFCs nanoemulsions and nanoparticles (NPs) are highly used in diagnostic imaging and enable novel imaging technology in clinical imaging modalities to notice and image pathological and physiological alterations. Therapeutics with PFCs such as the innovative approach to preventing thrombus formation, PFC nanodroplets utilized in ultrasonic medication delivery in arthritis, or PFC-based NPs such as Perfluortributylamine (PFTBA), Pentafluorophenyl (PFP), Perfluorohexan (PFH), Perfluorooctyl bromide (PFOB), and others, recently become renowned for oxygenating tumors and enhancing the effects of anticancer treatments as oxygen carriers for tumor hypoxia. In this review, we will discuss the recent advancements that have been made in PFC's applications in theranostic (therapeutics and diagnostics) as well as assess the benefits and drawbacks of these applications.

3.
J Biotechnol ; 354: 63-71, 2022 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-35724764

RESUMO

Probiotics are beneficial bacteria that have a significant effect on host health and they are widely used in preventing and treating diseases. Nowadays probiotics are present in food, drug and several commercial complement products. In recent years the use of probiotics in the nanotechnology area, especially in nanoparticle synthesis, has significantly been increased. In this review, after some introduction about probiotic and their advantages, all the nanoparticles produced by probiotics are reviewed and discussed. Furthermore, biosynthetic mechanisms of nanoparticles and its applications in cancer therapy, antibacterial and photo catalytic activities, are also discussed.


Assuntos
Nanopartículas , Probióticos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bactérias , Probióticos/uso terapêutico
4.
Toxicol Rep ; 9: 647-655, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35399215

RESUMO

In this work, we did our best to develop a novel and interesting analytical method based on coupling of spectrofluorimetry with first-order multivariate calibration techniques for simultaneous determination of lead (Pd), zinc (Zn) and cadmium (Cd) in HeLa cells. To achieve this goal, quenching of the emission of graphene (GR) was individually investigated in the presence of Pb, Zn and Cd and then, according to the linear ranges obtained from individual calibration graphs, a multivariate calibration model was developed based on modeling of the quenching of the emission of GR in the presence of the mixtures of Pb, Zn and Cd. First-order multivariate calibration models were constructed by partial least squares (PLS), principal component regression (PCR), orthogonal signal correction-PLS (OSC-PLS), continuum power regression (CPR), robust continuum regression (RCR) and partial robust M-regression (PRM) and their performances were evaluated and statistically compared. Finally, the OSC-PLS was chosen as the best model with the best practical performance for analytical purposes.

5.
Pharm Dev Technol ; 27(1): 25-39, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34895024

RESUMO

Due to the rapid clearance of external agents from the surface of the cornea, conventional ocular formulations usually require frequent and long duration of administration to achieve a therapeutic level of the drug on the cornea which can be conquered using prolonged-release nanofibrous inserts. In the present study, for the first time, polymeric nanofibers of itraconazole (ITZ), a potent triazole antifungal agent, were prepared as ocular inserts to enhance the topical ocular delivery of the drug. Three different nanofibers were prepared by electrospinning using polyvinyl alcohol-cellulose acetate and polycaprolactone-polyethylene glycol 12 000 polymeric blends. Nanofibers indicated uniform structures with the mean diameter ranging between 137 and 180 nm. Differential scanning calorimetry and Fourier-transform infrared spectroscopy confirmed the amorphous state of the drug in the formulations and the no drug-polymer interaction. Appropriate stability, suitable flexibility, and 2.2-3.9 MPa tensile strength were observed. Formulations indicated antifungal efficacy against Candida albicans and Aspergillus fumigatus and cell viability >70% at different concentrations. Results of bioassay against Candida albicans exhibited prolonged in vitro release of 50-70% of ITZ for almost 55 days. The results suggested that the nanofibers could be considered suitable for prolonged delivery of the ITZ as an antifungal requiring frequent and long duration of administration.


Assuntos
Itraconazol , Nanofibras , Antifúngicos , Itraconazol/química , Itraconazol/farmacologia , Nanofibras/química , Polímeros/química , Álcool de Polivinil/química
6.
J Biomed Mater Res A ; 109(11): 2164-2172, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33866680

RESUMO

Oral administration of insulin is one of the most challenging topics within this area, because insulin is degraded in stomach before it enters the bloodstream. In this study, for the first time, a nano-carrier for controlled and targeted oral delivery of insulin was developed using de-esterified Tragacanth and chitosan. The fabricated nanoparticles were synthesized using coacervation technique and their properties were optimized using response surface methodology. The effect of experimental variables on the particle size and loading efficiency was examined. In addition, the interactions between components were analyzed using Fourier transform infrared. The thermal stability of nanoparticles was studied by thermal gravimetric analysis. The insulin loading efficiency was measured and in vitro release profile and ex vivo insulin permeability was determined. Optimized nanoparticles showed spherical shape with a size less than 200 nm and zeta potential of +17 mV. Owing to their nanoscale dimensions and mucoadhesiveness, nanoparticles were synthesized using medium molecular weight of Chitosan. The insulin loading efficacy for the system was 6.4%, released under simulated gastrointestinal conditions in a pH-dependent manner. Based on all of the obtained results, it can be concluded that these nanoparticles can potentially be utilized as a carrier for the oral insulin delivery.


Assuntos
Quitosana , Portadores de Fármacos , Insulina , Nanocompostos , Tragacanto , Administração Oral , Animais , Quitosana/química , Quitosana/farmacologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Humanos , Insulina/química , Insulina/farmacocinética , Insulina/farmacologia , Masculino , Nanocompostos/química , Nanocompostos/uso terapêutico , Ratos , Ratos Wistar , Tragacanto/química , Tragacanto/farmacologia
7.
Adv Pharm Bull ; 11(2): 311-317, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33880353

RESUMO

Purpose: The present study aimed to formulate PLGA and PLGA-PEG-galactosamine nanoparticles (NPs) loaded with amphotericin B with appropriate physicochemical properties and antifungal activity. PLGA was functionalized with GalN to increase the adhesion and antifungal activity of NPs against Candida albicans. Methods: The physicochemical properties of NPs were characterized by particle size determination, zeta potential, drug crystallinity, loading efficiency, dissolution studies, differential scanning calorimeter (DSC), X-ray powder diffraction (XRPD), and Fourier transform infrared (FT-IR). Antifungal activity of the NPs at different drug/polymer ratios was examined by determining minimum inhibitory concentrations (MICs). Results: the FT-IR and 1 HNMR analysis successfully confirmed the formation of PLGA- PEG-GalN NPs. The PLGA NPs were in the size range of 174.1 ± 3.49 to 238.2±7.59 nm while PLGA-GalN NPs were 255.6 ±4.08 nm in size , respectively. Loading efficiency was in the range of 67%±2.4 to 77%±1.6, and entrapment efficiency in the range of 68.185%±1.9 to 73.05%±0.6. Zeta potential and loading efficiency for PLGA-GalN NPs were -0.456, 71%. The NPs indicated an amorphous status according to XRPD patterns and DSC thermograms. The PLGA-PEG-GalN NPs showed higher fungistatic activity than PLGA NPs. Conclusion: the results demonstrated that the antifungal activity of PLGA-PEG-GalN NPs was higher than pure amphotericin B and PLGA NPs.

8.
Adv Pharm Bull ; 9(4): 593-600, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31857963

RESUMO

Purpose: The purpose of the present study was to improve the ocular delivery for ketorolac tromethamine (KT) used to treat inflammation of the eye. Methods: Eudragit nanoparticles loaded with KT were prepared and incorporated in polyvinyl alcohol (PVA) and hydroxyethyl cellulose (HEC) films. Nanoparticles were characterized by Fourier transform-infrared (FT-IR), scanning electron microscopy (SEM). Physicochemical properties and encapsulation effciency were investigated for nanoparticles. Also, the inserts were evaluated for their physiochemical parameters like percentage moisture absorption, percentage moisture loss, thickness and folding endurance. Results: Mean particle size and zeta potential were in range of 153.8-217 nm and (-10.8) - (-40.7) mV, respectively. The results show that the use of a surfactant has not led to any major change on drug loading. The loading increases with the amount of polymer. The insert had a thickness varying from 0.072 ± 0.0098 to 0.0865 ± 0.0035 mm. The thicknesses of the inserts and the folding endurance increased with the total polymer concentration. The physicochemical properties showed that the Eudragit® L-100 nanoparticles loaded PVA-HEC films could be an effective carrier for KT. Conclusion: For the first time, inserts of Eudragit nanoparticles were successfully prepared for ophthalmic drug delivery system to prevent frequent drug administration and enhance patient compliance.

9.
Adv Pharm Bull ; 9(2): 249-254, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31380250

RESUMO

Purpose: The objective of this study was to improve the permeability and water solubility rate of a poor water soluble drug, cyclosporine A (CsA). Methods: In order to improve the drug dissolution rate and oral bioavailability, electrospinning method was used as an approach to prepare. The fibers were evaluated for surface morphology, thermal characterizations, drug crystallinity, in vitro drug release and in vivo bioavailability studies. Results: Scanning electron microscope (SEM) results confirmed that the fibers were in microsize range and the size of the fibers was in the rang of 0.2 to 2 micron. Differential scanning calorimetry (DSC) and powder X-ray diffractometry (XRPD) analysis ensured that the crystalline lattice of drug were weakened or destroyed in the fibers. The drug release was 15.28%, 20.67%, and 32.84% from pure drug, fibers of formulation B, and formulation A, respectively. In vivo study results indicated that the bioavailability parameters of the optimized fiber formulation were improved and the maximum concentration (Cmax) were significantly higher for fibers (3001 ng/mL) than for pure drug (2550 ng/mL). The dissolution rate of the formulations was dependent on the nature and ratio of drug to carriers. Conclusion: The physicochemical properties showed that the optimized mixture of polyethylene glycol (PEG) and povidone (PVP) fibers could be an effective carrier for CsA delivery. PEG and PVP fibers improved the absolute bioavailability and drug dissolution rate with appropriate physicochemical properties.

10.
Int J Biol Macromol ; 120(Pt A): 587-595, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30170050

RESUMO

In this work, we have fabricated a novel amperometric cholesterol (CHO) biosensor because of the importance of determination of CHO levels in blood which is an important parameter for diagnosis and prevention of disease. To achieve this goal, cholesterol oxidase, cholesterol esterase and horseradish peroxidase were simultaneously co-immobilized onto a glassy carbon electrode (GCE) modified with gold nanoparticles/chitin-ionic liquid/poly(3,4-ethylenedioxypyrrole)/graphene-multiwalled carbon nanotubes-1,1'-ferrocenedicarboxylic acid-ionic liquid. Modifications applied to the bare GCE were characterized by cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. The biosensor detected CHO in linear ranges of 0.1-25 µM and 25-950 µM with a detection limit of 0.07 µM. The sensitivity of the biosensor was estimated to be 6.6 µA µM-1 cm-2, its response time was <5 s and Michaelis-Menten constant was calculated to be 0.12 µM. Results obtained in this study revealed that the biosensor was selective, sensitive, stable, repeatable and reproducible. Finally, the biosensor was successfully applied to the determination of CHO levels in rats plasma.


Assuntos
Técnicas Biossensoriais/instrumentação , Colesterol Oxidase/química , Colesterol/sangue , Técnicas Eletroquímicas/métodos , Peroxidase do Rábano Silvestre/química , Esterol Esterase/química , Animais , Benzoatos/química , Quitina/química , Eletrodos , Enzimas Imobilizadas/química , Compostos Ferrosos/química , Vidro/química , Ouro/química , Limite de Detecção , Nanopartículas Metálicas/química , Metalocenos , Nanotubos de Carbono/química , Pirróis/química , Ratos , Reprodutibilidade dos Testes
11.
Iran J Pharm Res ; 17(2): 470-479, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29881405

RESUMO

The objective of this study was to develop a novel bacterially-triggered micro-particular system of de-esterified tragacanth (DET) in combination with Eudragit S-100 coated capsules for colon drug delivery of 5-fluorouracil (5-FU) using microemulsion method. The loading study was conducted at different drug-to-polymer ratios and cross-linker concentrations. The maximum loading efficiency was achieved, 44.1% at 1:5 drug-to-polymer ratio and 0.7% cross-linker concentration. The FTIR results also confirmed the encapsulation of 5-FU in microspheres. The release profile was dependent on the cross-linker concentration, environmental pH, and presence of pectinase enzyme. Microspheres inserted into Eudragit S-100 coated capsules released less than 5% of the drug at stomach and small intestine pH levels, whereas 70% of the drug was released at colon pH levels, and about 25% of the drug did not release unless in the presence of pectinase enzyme. To omit burst release, microspheres were washed with water, and the release became pH independent, and was just achieved in the presence of pectinase enzyme. 5-FU loaded microspheres with an IC50 value of 80 µg/mL were as effective as the free drug on HT-29. Generally, the results demonstrated that drug-loaded microspheres inserted into Eudragit S-100 coated capsules can be effective for colon-targeted delivery.

12.
J Pharm Biomed Anal ; 156: 23-35, 2018 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-29684908

RESUMO

In this work, voltammetric data recorded by a glassy carbon electrode (GCE) was used to investigate the interactions of tolcapone (Tasmar, TAS) with human serum albumin (HSA) at the electrode surface. The recorded voltammetric data was also combined with spectroscopic data to construct an augmented data matrix which was analysed by multivariate curve resolution-alternating least squares (MCR-ALS) as an efficient chemometric tool to obtain more information about TAS-HSA interactions. The results of MCR-ALS confirmed formation of one complex species (HSA-TAS2) and application of MCR-BANDS to the results of MCR-ALS confirmed the absence of rotational ambiguities and existing unambiguous and reliable results. Binding of TAS to HSA was also modeled by molecular docking and the results showed that the TAS was bound to sub-domain IIA of HSA which were compatible with the ones obtained by recording experimental data. Hard-modeling of combined voltammetric and spectroscopic data by EQUISPEC helped us to compute binding constant of HSA-TAS2 complex species which was compatible with the binding constant value obtained by direct analysis of experimental data. Finally, a new electroanalytical method was developed based on TAS-HSA interactions for determination of HSA in two ranges of 0-541 nM and 541-1200 nM with a limit of detection of 0.04 nM and a sensitivity of 0.02 µA nM-1.


Assuntos
Antiparkinsonianos/química , Benzofenonas/química , Técnicas Biossensoriais/métodos , Nitrofenóis/química , Albumina Sérica Humana/análise , Técnicas Biossensoriais/instrumentação , Carbono/química , Eletrodos , Simulação de Acoplamento Molecular , Ligação Proteica , Albumina Sérica Humana/química , Espectrometria de Fluorescência , Tolcapona
13.
Talanta ; 183: 1-10, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29567149

RESUMO

In this work, fabrication of a novel and ultrasensitive electrochemical biosensor based on immobilization of tyrosine hydroxylase onto palladium-platinum bimetallic alloy nanoparticles/chitosan-1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide/graphene-multiwalled carbon nanotubes-IL/glassy carbon electrode for determination of L-tyrosine in some high tyrosine foods including cheese, egg and yogurt was reported. Immobilization of tyrosine hydroxylase onto the surface of the biosensor was performed by cross-linking tyrosine hydroxylase and chitosan through the addition of glutaraldehyde. Enzymatic biosensors employ the affinity and selectivity of catalytically active proteins towards their target molecules and here, the tyrosine hydroxylase selectively catalyzes the conversion of tyrosine to levodopa which can be oxidized at lower potentials than tyrosine. The modifications were characterized by electrochemical impedance spectroscopy, cyclic voltammetry, energy dispersive X-ray spectroscopic and scanning electron microscopy. Under optimal conditions, the biosensor detected tyrosine in concentration ranges of 0.01 × 10-9 to 8.0 × 10-9 mol L-1 and 8.0 × 10-9 to 160.0 × 10-9 mol L-1 with a limit of detection of 0.009 × 10-9 mol L-1. The biosensor was able to selective determination of tyrosine even in the presence of common interferents therefore, the biosensor was highly selective. The biosensor also showed good operational stability, antifouling properties, sensitivity, repeatability and reproducibility.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas , Análise de Alimentos/métodos , Tirosina 3-Mono-Oxigenase/metabolismo , Tirosina/análise , Queijo/análise , Conformação Molecular , Óvulo/química , Iogurte/análise
14.
Braz. J. Pharm. Sci. (Online) ; 54(4): e17228, 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1001591

RESUMO

In the current work, a sustained drug delivery system of flutamide (FLT) was developed using Poly(D,L-lactide-co-glycolide) (PLGA) decorated bypoly(ethylene glycol) (PEG) grafted prazosin (PLGA-PEG-Praz) as a targeting moiety. In a multi-step reaction, PLGA was linked to PEG and prazosin. The structure of the synthesized polymers was confirmed by FTIR and 1H-NMR. Flutamide-loaded nanoparticles were prepared by quasi-emulsion solvent diffusion technique. The nanoparticles were evaluated for size, zeta potential, polydispersity index, drug crystallinity, loading efficiency, and release properties. Also, the physicochemical properties of the nanoparticles were analyzed using Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry, and Powder X-Ray Diffractometry (XRD). The particle size of nanoparticles was ranged between 191 and 249 nm. Loading efficiency of nanoparticles was about 43%-69%. Results showed a steady release rate for nanoparticles compared to that of a pure drug powder. SEM characterization confirmed that particles were in nanosize range. DSC and XRPD results verified a decrease in drug crystallinity in the prepared formulations. In conclusion, the results of this study showed that PLGA-PEG-Praz nanoparticles could be a good choice to improve the physicochemical properties of the drug and these formulations can increase Flutamide efficacy.


Assuntos
Prazosina/análise , Nanopartículas , Flutamida/uso terapêutico , Neoplasias da Próstata/fisiopatologia , Espectroscopia de Infravermelho com Transformada de Fourier/instrumentação
15.
Pharm Res ; 34(2): 301-309, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27928646

RESUMO

PURPOSE: Nystatin loaded PLGA and PLGA-Glucosamine nanoparticles were formulated. PLGA were functionalized with Glucosamine (PLGA-GlcN) to enhance the adhesion of nanoparticles to Candida Albicans (C.albicans) cell walls. METHOD: Quasi-emulsion solvent diffusion method was employed using PLGA and PLGA-GlcN with various drug-polymer ratios for the preparation of nanoparticles. The nanoparticles were evaluated for size, zeta potential, polydispersity index, drug crystallinity, loading efficiency and release properties. DSC, SEM, XRPD, 1H-NMR, and FT-IR were performed to analyze the physicochemical properties of the nanoparticles. Antifungal activity of the nanoparticles was evaluated by determination of MICs against C.albicans. RESULTS: The spectra of 1H-NMR and FT-IR analysis ensured GlcN functionalization on PLGA nanoparticles. SEM characterization confirmed that particles were in the nanosize range and the particle size for PLGA and PLGA-GlcN nanoparticles were in the range of 108.63 ± 4.5 to 168.8 ± 5.65 nm and 208.76 ± 16.85 nm, respectively. DSC and XRPD analysis ensured reduction of the drug crystallinity in the nanoparticles. PLGA-GlcN nanoparticles exhibit higher antifungal activity than PLGA nanoparticles. CONCLUSION: PLGA-GlcN nanoparticles showed more antifungal activity with appropriate physicochemical properties than pure Nystatin and PLGA nanoparticles.


Assuntos
Antifúngicos/química , Glucosamina/química , Ácido Láctico/química , Nanopartículas/química , Nistatina/química , Ácido Poliglicólico/química , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Química Farmacêutica/métodos , Portadores de Fármacos/química , Nistatina/farmacologia , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
16.
Artif Cells Nanomed Biotechnol ; 44(2): 497-503, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-25289448

RESUMO

The aim of the present study was to formulate methylprednisolone acetate -Eudragit(®) RS100 nanofibers and nanobeads by the electrospinning method. The physicochemical characteristics of the prepared electrospuns were assessed as well. The particle size and morphology were evaluated using scanning electron microscopy. The crystallinity of the drug in the nanofibers and nanobeads obtained was also studied by X-ray crystallography and differential scanning calorimetry (DSC) thermograms. In addition, FT-IR spectroscopy was applied to investigate any possible chemical interaction between the drug and carrier during the preparation process. The drug release kinetics were considered, to predict the release mechanism. Increasing the concentration of the injected solution resulted in the production of more nanofibers and less nanobeads, with the particle size ranging from 100 to 500 nm. The drug crystallinity was decreased during the electrospinning process; however, no interaction between drug and polymer was observed. The electrospuns showed faster drug release pattern compared to the pure drug. The release data were best fitted to the Weibull model, in which the corresponding shape factor values of the model were less than 0.75 indicating the diffusion mechanism of drug release. In conclusion, electrospinning could be considered as a simple and cost effective method for fabricating the drug: polymer nanofibers and nanobeads.


Assuntos
Fenômenos Químicos , Portadores de Fármacos/química , Eletricidade , Metilprednisolona/análogos & derivados , Nanofibras/química , Nanotecnologia/métodos , Ácidos Polimetacrílicos/química , Liberação Controlada de Fármacos , Cinética , Metilprednisolona/química , Acetato de Metilprednisolona
17.
Adv Pharm Bull ; 4(4): 391-9, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25436197

RESUMO

PURPOSE: The purpose of this study was to prepare and characterize solid dispersion formulation of furosemide to enhance dissolution rate. METHODS: Solid dispersions with different drug: carrier ratios were prepared by cogrinding method using crospovidone and microcrystalline cellulose as carrier. The physical state and interactions between the drug and carrier were characterized by Fourier transform infrared spectroscopic (FT-IR) and X ray diffraction (XRD). RESULTS: Solid dispersions (especially with drug: Carrier ratio of 1:2) showed a higher dissolution rate than their respective physical mixture and pure furosemide. Dissolution rate in pH 5.8 was also higher than pH 1.2. The XRD analysis showed that crystalline form was changed to the amorphous state in the solid dispersions. FT-IR analysis did not show any physicochemical interactions in the solid dispersion formulations. Release kinetic of formulations were fitted best to the Weibull and Wagner log probability (linear kinetic) as well as suggested 2 and Gompertz (non-linear kinetic) models. CONCLUSION: The dissolution properties of furosemide were improved with the use of hydrophilic carriers in solid dispersions due to change in the crystalline form of the drug and more intimate contact between drug and carriers which was dependent on the type and ratio of carrier as well as dissolution medium pH.

18.
Bioimpacts ; 4(3): 141-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25337467

RESUMO

INTRODUCTION: The main objective of this study was preparation and characterization of solid dispersion of piroxicam to enhance its dissolution rate. METHODS: Solid dispersion formulations with different carriers including crospovidone, microcrystalline cellulose, Elaeagnus angustifolia fruit powder, with different drug to carrier ratios were prepared employing cogrinding method. Dissolution study of the piroxicam powders, physical mixtures and solid dispersions was performed in simulated gastric fluid and simulated intestinal fluid using USP Apparatus type II. The physical characterization of formulations were analyzed using powder X ray diffraction (PXRD), particle size analyzer and differential scanning calorimetry (DSC). Interactions between the drug and carriers were evaluated by Fourier transform infrared (FT-IR) spectroscopic method. RESULTS: It was revealed that all of three carriers increase the dissolution rate of piroxicam from physical mixtures and especially in solid dispersions compared to piroxicam pure and treated powders. PXRD and DSC results confirmed the reduction of crystalline form of piroxicam. FT-IR analysis did not show any physicochemical interaction between drug and carriers in the solid dispersion formulations. CONCLUSION: Dissolution rate was dependent on the type and ratio of drug to carrier as well as pH of dissolution medium. Dissolution data of formulations were fitted well into the linear Weibull as well as non-linear logistic and suggested models.

19.
Colloids Surf B Biointerfaces ; 116: 751-6, 2014 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-24581925

RESUMO

The mesoporous glass-ceramic (GC) was employed as a carrier to investigate its capability for pharmaceutical applications. Piroxicam (PX) as a model drug was loaded in the GC by using of solvent evaporation technique. The physicochemical properties and morphology of the powders were evaluated employing X-ray powder diffractometry (XRPD), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The drug adsorption isotherms were assessed as well. Drug release profiles were examined by fitting the data to the 10 common kinetic models. The specific surface area, Vm (the volume of the N2 adsorbed on the 1g of the GC when the monolayer is complete) and the average pore diameter of the GC powder before and after loading process were measured by the Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) analysis benefiting N2 adsorption/desorption isotherms. The ideal loading of PX in the GC was 41.8%. The average pore diameter for the GC was determined to be about 10nm. The Freundlich model was found to be the best adsorption isotherm. Decrease of the GC specific surface area and Vm values were observed after loading process. Drug release data were best fitted to the Weibull model with the shape factor of 0.4-0.7 signifying the Fickian diffusion of PX from the GC. Accordingly, the GC could be considered as a suitable adsorbent to develop an oral drug delivery system.


Assuntos
Cerâmica/química , Fosfatos/química , Piroxicam/química , Físico-Química , Vidro/química , Tamanho da Partícula , Porosidade , Propriedades de Superfície
20.
J Pharm Pharm Sci ; 15(4): 583-91, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23106960

RESUMO

PURPOSE: Drug release from nanosystems at the sites of either absorption or effect biophase is a major determinant of its biological action. Thus, in vitro drug release is of paramount importance in gaining insight for the systems performance in vivo. METHODS: A novel in vitro in vivo correlation, IVIVC, model denoted as double reciprocal area method was presented and applied to 19 drugs from 55 nano formulations with total 336 data, gathered from literature. RESULTS: The proposed model correlated the in vitro with in vivo parameters with overall error of 12.4 ± 3.9%. Also the trained version of the model predicted the test formulations with overall error of 15.8 ± 3.7% indicating the suitability of the approach. A theoretical justification was provided for the model considering the unified classical release laws. CONCLUSION: The model does not necessitate bolus intravenous drug data and seems to be suitable for IVIVC of drugs with release rate-limited absorption.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/administração & dosagem , Nanotecnologia/métodos , Farmacocinética , Absorção , Área Sob a Curva , Química Farmacêutica/métodos , Modelos Biológicos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...