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1.
Chemistry ; 30(44): e202400452, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-38837264

RESUMO

Bio-active ethylcellulose (EC) polymeric films have been obtained by incorporating curcumin (curc) and Ag(I)-based compounds, known for their antioxidant and antimicrobial activity, respectively, within the polymeric matrix. The recently reported Ag(I) coordination polymer, in both its structural forms (α-[(bpy)Ag(OTf)]∞ and ß-{[(bpy)Ag][OTf]}∞), and the [(bpy)Ag(OTf)]∞-curc polymeric co-crystal (bpy=2,2'-bipyridine; OTf=trifluoromethanesulfonate) have been selected as Ag(I) species. The hybrid composite films have been prepared through the simple solvent casting method and characterized through Powder X-Ray Diffraction (PXRD), Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscope (SEM), UV-vis spectroscopy. The deep investigation of the film samples highlighted the non-inert behaviour of EC towards these specific active ingredients. Antimicrobial tests showed that EC films embedding the Ag(I)-based compounds present good antimicrobial performance, in particular against Staphylococcus aureus, used as a model of Gram-positive bacteria. In addition, Silver migration tests, performed on the Ag(I)-incorporating EC films, evidenced low values of silver release particularly in the case of the EC films incorporating [(bpy)Ag(OTf)]∞-curc.

2.
J Microencapsul ; 40(5): 345-356, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37129865

RESUMO

This research aims to develop bitter taste-masking microcapsules containing azithromycin (AZI) by a simpler and familiar method, fluid-bed coating technology, in comparison with Zithromax®. Cores of microcapsules, AZI microparticles, were prepared by fluid-bed granulation, then taste-masking polymer was covered on by fluid-bed coating technique. Eudragit L100, Eudragit RL100, and ethyl cellulose in single and combined with Eudragit L100 and Eudragit E100 were used as taste-masking polymers. The obtained microcapsules were characterised by taste-masking ability, in vitro release, SEM, coating thickness, and coating efficiency. Combination of ethyl cellulose and Eudragit E100 (3:1) in coating thickness of 45.13 ± 2.12% w/w prevents AZI release from microcapsules below bitter taste threshold (1.78 ± 1.17 µg/ml). Bioavailability of powders containing AZI microcapsules and pH modulators (50 mg Na3PO4 and 35 mg Mg(OH)2) was not significantly different from the reference product (Zithromax®, Pfizer, New York, NY) in the rabbit model (p > 0.05). These results support the possibility of developing a generic product containing AZI.


Assuntos
Azitromicina , Paladar , Animais , Coelhos , Pós , Cápsulas , Solubilidade
3.
Molecules ; 28(4)2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36838759

RESUMO

This report presents a nanoparticulate platform for cannabidiol (CBD) for topical treatment of inflammatory conditions. We have previously shown that stabilizing lipids improve the encapsulation of CBD in ethyl cellulose nanoparticles. In this study, we examined CBD release, skin permeation, and the capability of lipid-stabilized nanoparticles (LSNs) to suppress the release of IL-6 and IL-8. The nanoparticles were stabilized with cetyl alcohol (CA), stearic acid (SA), lauric acid (LA), and an SA/LA eutectic combination (SALA). LSN size and concentration were measured and characterized by differential scanning calorimetry (DSC), in vitro release of loaded CBD, and skin permeability. IL-6 and IL-8 secretions from TNF-α-induced HaCaT cells were monitored following different LSN treatments. CBD released from the LSNs in dispersion at increasing concentrations of polysorbate 80 showed non-linear solubilization, which was explained by recurrent precipitation. A significant high release of CBD in a cell culture medium was shown from SALA-stabilized nanoparticles. Skin permeation was >30% lower from SA-stabilized nanoparticles compared to the other LSNs. Investigation of the CBD-loaded LSNs' effect on the release of IL-6 and IL-8 from TNF-α-induced HaCaT cells showed that nanoparticles stabilized with CA, LA, or SALA were similarly effective in suppressing cytokine release. The applicability of the CBD-loaded LSNs to treat topical inflammatory conditions has been supported by their dermal permeation and release inhibition of pro-inflammatory cytokines.


Assuntos
Anti-Inflamatórios , Canabidiol , Nanopartículas , Anti-Inflamatórios/farmacologia , Canabidiol/farmacologia , Citocinas , Interleucina-6 , Interleucina-8 , Lipídeos , Nanopartículas/química , Fator de Necrose Tumoral alfa , Células HaCaT , Humanos
4.
Mol Pharm ; 19(8): 2712-2724, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35476407

RESUMO

In the present work, an insoluble polymer, i.e., ethyl cellulose (EC), was combined with the water-soluble polyvinylpyrrolidone (PVP) as a carrier system for the formulation of amorphous solid dispersions. The rationale was that by conjoining these two different types of carriers a more gradual drug release could be created with less risk for precipitation. Our initial hypothesis was that upon contact with the dissolution medium, PVP would be released, creating a porous EC matrix through which the model drug indomethacin could diffuse. On the basis of observations of EC as a coating material, the effect of the molecular weight of PVP, and the ratio of EC/PVP on the miscibility of the polymer blend, the solid state of the solid dispersion and the drug release from these solid dispersions were investigated. X-ray powder diffraction, modulated differential scanning calorimetry, and solid-state nuclear magnetic resonance were used to unravel the miscibility and solid-state properties of these blends and solid dispersions. Solid-state nuclear magnetic resonance appeared to be a crucial technique for this aspect as modulated differential scanning calorimetry was not sufficient to grasp the complex phase behavior of these systems. Both EC/PVP K12 and EC/PVP K25 blends were miscible over the entire composition range, and addition of indomethacin did not alter this. Concerning the drug release, it was initially thought that more PVP would lead to faster drug release with a higher probability that all of the drug molecules would be able to diffuse out of the EC network as more pores would be created. However, this view on the release mechanism appeared to be too simplistic as an optimum was observed for both blends. On the basis of this work, it could be concluded that drug release from this complex ternary system was affected not only by the ratio of EC/PVP and the molecular weight of PVP but also by interactions between the three components, the wettability of the formulations, and the viscosity layer that was created around the particles.


Assuntos
Excipientes , Povidona , Varredura Diferencial de Calorimetria , Celulose/análogos & derivados , Indometacina/química , Polímeros/química , Porosidade , Povidona/química , Solubilidade , Difração de Raios X
5.
Mol Pharm ; 19(5): 1477-1487, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35347993

RESUMO

Flufenamic acid (FFA) is a highly polymorphic drug molecule with nine crystal structures reported in the Cambridge Structural Database. This study explores the use of synchrotron X-ray powder diffraction combined with differential scanning calorimetry to study crystallization and polymorphic phase transitions upon heating FFA-polymer amorphous solid dispersions (ASDs). Ethyl cellulose (EC, 4 cp) and hydroxypropylmethylcellulose (HPMC) grades with different viscosities and substitution patterns were used to prepare dispersions with FFA at 5:1, 2:1, 1:1, and 1:5 w/w drug/polymer ratios by quench cooling. We employed a 6 cp HPMC 2910 material and two HPMC 2208 samples at 4000 and 100 000 cp. Hyphenated X-ray diffraction (XRD)-differential scanning calorimetry (DSC) studies show that the 6 and 100 000 cp HPMCs and 4 cp EC polymers can stabilize FFA form IV by inhibiting the transition to form I during heating. It appears that the polymers stabilize FFA in both amorphous and metastable forms via a combination of intermolecular interactions and viscosity effects. Increasing the polymer content of the ASD also inhibits polymorphic transitions, with drug/polymer ratios of 1:5 w/w resulting in FFA remaining amorphous during heating. The comparison of FFA ASDs prepared with different samples of HPMCs and ECs suggests that the chemical substitution of the polymer (HPMC 2208 has 19-24% methoxy groups and 4-12% hydroxypropyl groups, while HPMC 2910 has 28-30% methoxy groups and 7-12% hydroxypropyl groups) plays a more significant role in directing polymorphic transitions than the viscosity. A previously unreported polymorph of FFA was also noted during heating but its structure could not be determined.


Assuntos
Ácido Flufenâmico , Polímeros , Varredura Diferencial de Calorimetria , Derivados da Hipromelose/química , Polímeros/química , Solubilidade , Difração de Raios X
6.
Cellulose (Lond) ; 29(7): 3947-3961, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35399619

RESUMO

Ethyl cellulose (EC) was filled with bentonite (Bent) particles by mechanical dispersion to produce composite film materials that were studied using various methods. According to X-ray diffraction (XRD) analysis, the inter-chain separation length was larger in EC/Bent composite then those in pure polymer. Infrared spectrometry indicated a formation of hydrogen bonds between the hydroxyl groups of EC and the silanol groups of clay. Tests showed an increase in tensile strength of the polymer material (by 35-40%) when doped with bentonite. It was found that modification of polymer with bentonite resulted in increasing of the adsorption efficiency of methylene blue (MB): the equilibrium concentration of MB ions in adsorbent phase increased 2.5 times. The MB adsorption kinetics obeyed the pseudo-first-order mechanism. Isotherms were in good agreement with Langmuir model. For the composite, the maximum monolayer adsorption capacity was 4 times higher than that for pure polymer.

7.
Pharm Dev Technol ; 26(3): 335-348, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33430677

RESUMO

A dual pH- and time-dependent polymeric coated capsule was developed to achieve the site specificity of simvastatin (SIM) release in the colon. To improve the SIM solubility, soluplus-based nanosuspension of the drug were prepared by applying the anti-solvent crystallization technique; this was then followed by lyophilization. Particle size, polydispersity index, and saturation solubility were evaluated. The optimized nanosuspension was combined with SLS and freeze-dried before filling into hard gelatin capsules. Drug release characteristics of the coated capsules were studied in HCl 0.1 N, the phosphate buffers 6.8 and 7.4, and the simulated colonic fluid (pH 6.8). The in-vitro cytotoxic effects of SIM nanoparticles against HT29 cells were then evaluated using the MTT assay. The prepared nanoparticles were spherical with a mean size of 261.66 nm, the zeta potential of -18.20 and the dissolution efficiency of 59.71%. X-ray diffraction and differential scanning calorimetry studies showed that the nanosizing technique transformed the crystalline drug into the more soluble amorphous form. The coated capsules had no release in the gastric media, providing the specific delivery of SIM in the colon. The cytotoxic effect of the SIM nanoparticles was significantly increased, as compared to the free SIM. The findings, therefore, showed that the coated capsules using the two polymers of ethyl cellulose and Eudragit S100 could be suitable for the colon target delivery of SIM.


Assuntos
Anticolesterolemiantes/administração & dosagem , Antineoplásicos/administração & dosagem , Preparações de Ação Retardada/química , Sinvastatina/administração & dosagem , Anticolesterolemiantes/química , Anticolesterolemiantes/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Liberação Controlada de Fármacos , Células HT29 , Humanos , Concentração de Íons de Hidrogênio , Sinvastatina/química , Sinvastatina/farmacologia
8.
AAPS PharmSciTech ; 22(7): 241, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34590171

RESUMO

The objective of this study was to stabilize the enteric property of bleached shellac by composite formation with ethyl cellulose. The composite film at the ratio of 9:1, 8:2, 7:3, 6:4, and 5:5 was prepared by the film casting method. The physicochemical properties were acid value, insoluble solid, water permeability coefficient, % polarity, mechanical property, FTIR, PXRD, DSC, % solubility in aqueous, and various pH (1.2 and 7.4). All the films were able to protect against the low pH and water. The total solubility at pH 7.4 was reported for the low ratio of ethyl cellulose (9:1 and 8:2). The stability of all films was then investigated for 180 days. The results demonstrated that the ethyl cellulose could stabilize the bleached shellac indicated by the low changes in acid value and insoluble solid. The higher ratio of ethyl cellulose contributed to the lower polymerization during storage. The results were due to the protection of the bleached shellac's active sites. The entanglement of ethyl cellulose caused interaction difficulties between active groups leading to stabilized bleached shellac. The proper ratio was 7:3 because of high solubility, and low polymerization. The findings demonstrated that the composite film could improve the enteric property of bleached shellac for a long period.


Assuntos
Resinas Vegetais , Permeabilidade , Polimerização , Solubilidade
9.
Pharm Dev Technol ; 25(2): 187-196, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31637932

RESUMO

The effect of formulation and processing parameters on processability and release from hot-melt extrusion (HME)-based matrices appears to be API and polymer dependent. Accordingly, the aim of this work was to design an extended-release formulation of diclofenac sodium by using HME technique and design of experiment (DoE). The extrudates were prepared using a vertical lab-scale single screw extruder. A D-optimal design with 16 formulations was employed to evaluate and model the effect of diclofenac sodium, ethyl cellulose and Natrosol L levels on the release profile. The percentage of drug release at 2, 4, 8 and 16 h were the dependent variables. The formulation factors that affect drug release were identified and satisfactorily modeled. The goodness of fit (R2) and goodness of prediction (Q2) parameters obtained for release responses were 0.913 and 0.682 at 2 h, 0.946 and 0.67 at 4 h, 0.942 and 0.658 at 8 h, and 0.892 and 0.673 at 16 h, respectively. The design space of optimal fractions of ethyl cellulose and Natrosol L at various drug levels was successfully constructed by response surface methodology. In conclusion, the DoE approach helped to identify and quantify formulation variables that affect the release of diclofenac sodium from HME-based formulation.


Assuntos
Preparações de Ação Retardada/química , Diclofenaco/química , Celulose/análogos & derivados , Celulose/química , Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos/efeitos dos fármacos , Temperatura Alta , Polietilenoglicóis/química , Polímeros/química , Solubilidade/efeitos dos fármacos
10.
Sensors (Basel) ; 19(23)2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31771092

RESUMO

The development of a simple, low-cost sensor for the effective sensing of multiple gases in industrial or residential zones has been in high demand in recent days. In this article, we have proposed an optical sensor for the dual sensing of oxygen (O2) and ammonia (NH3) gases, which consists of oxygen and ammonia-sensitive fluorescent dyes coated individually on both sides of a glass substrate. An ethyl cellulose (EC) matrix doped with platinum (II) meso-tetrakis (pentafluorophenyl) porphyrin (PtTFPP) serves as the oxygen-sensing material, whereas the NH3-sensing material includes an eosin Y fluorescent indicator immobilized within a cellulose acetate (CA) matrix. Both the oxygen and ammonia-sensitive materials were excited by the same LED light source with a 405 nm peak wavelength, while the corresponding emissions were detected separately for the selective sensing of the gases under study. The dual gas sensor exhibits maximum sensitivities of around 60 and 20 for oxygen and ammonia gases, respectively. The high sensitivity and selectivity of the proposed optical dual sensor suggests the feasibility of the simultaneous sensing of oxygen and ammonia for practical applications.

11.
Sensors (Basel) ; 19(12)2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31248116

RESUMO

Novel hot electron-emitting working electrodes and conventional counter electrodes were created by screen printing. Thus, low-cost disposable electrode chips for bioaffinity assays were produced to replace our older expensive electrode chips manufactured by manufacturing techniques of electronics from silicon or on glass chips. The present chips were created by printing as follows: (i) silver lines provided the electronic contacts, counter electrode and the bottom of the working electrode and counter electrode, (ii) the composite layer was printed on appropriate parts of the silver layer, and (iii) finally a hydrophobic ring was added to produce the electrochemical cell boundaries. The applicability of these electrode chips in bioaffinity assays was demonstrated by an immunoassay of human C-reactive protein (i) using Tb(III) chelate label displaying long-lived hot electron-induced electrochemiluminescence (HECL) and (ii) now for the first time fluorescein isothiocyanate (FITC) was utilized as an a low-cost organic label displaying a short-lived HECL in a real-world bioaffinity assay.


Assuntos
Eletroquímica/métodos , Elétrons , Imunoensaio/métodos , Medições Luminescentes/métodos , Proteína C-Reativa/metabolismo , Calibragem , Eletrodos , Humanos , Propriedades de Superfície
12.
Molecules ; 24(8)2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30999569

RESUMO

BACKGROUND: This study is designed to discover a method for delivering an efficient potent pheophytin a (pheo-a) into more absorbed and small polymeric ethyl cellulose (EC) microparticles. METHODS: Silica gel and Sephadex LH-20 columns were used to isolate pheo-a from the chloroform extract of the edible plant, Suaeda vermiculata. Pheo-a was incorporated into EC microparticles using emulsion-solvent techniques. The antioxidant activity of pheo-a microparticles was confirmed by the level of superoxide radical (SOD), nitric oxide (NO), and reducing power (RP) methods. Meanwhile, the cytotoxic effect of the product was investigated on MCF-7 cells using MTT assay. RESULTS: Pheo-a was isolated from S. vermiculata in a 12% concentration of the total chloroform extract. The structures were confirmed by NMR and IR spectroscopic analysis. The formulated microparticles were uniform, completely dispersed in the aqueous media, compatible as ingredients, and had a mean diameter of 139 ± 1.56 µm as measured by a particle size analyzer. Pheo-a demonstrated a valuable antioxidant activity when compared with ascorbic acid. The IC50 values of pheo-a microparticles were 200.5 and 137.7 µg/mL for SOD, and NO respectively. The reducing power of pheo-a microparticles was more potent than ascorbic acid and had a 4.2 µg/mL for IC50 value. Pheo-a microparticles did not show notable cytotoxicity on the MCF-7 cell line (IC50 = 35.9 µg/mL) compared with doxorubicin (IC50 = 3.2 µg/mL). CONCLUSIONS: the results showed that water-soluble pheo-a microparticles were prepared with a valuable antioxidant activity in a wide range of concentrations with a noteworthy cytotoxic effect.


Assuntos
Antioxidantes , Celulose/análogos & derivados , Chenopodiaceae/química , Portadores de Fármacos , Feofitinas , Antioxidantes/química , Antioxidantes/farmacocinética , Antioxidantes/farmacologia , Celulose/química , Celulose/farmacocinética , Celulose/farmacologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/farmacologia , Humanos , Células MCF-7 , Feofitinas/química , Feofitinas/farmacocinética , Feofitinas/farmacologia
13.
J Sci Food Agric ; 99(8): 4063-4071, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30761529

RESUMO

BACKGROUND: Edible packaging and coating with natural antimicrobials such as essential oils is an emerging technology for the control of pathogen growth in meat products. This study aimed to explore ethyl cellulose (EC) of three viscosities for the structuring of cinnamon essential oil (CEO), and investigated the physicochemical properties of the resulting oleogel and its emulsion, as well as the corresponding antibacterial activity in model and actual environments (as in sausages). RESULTS: The network structure of CEO-EC oleogel was more compact with increased EC viscosity, thereby improving the binding capacity and stability of the oil. A positive correlation was found between EC viscosity and particle size of the CEO-EC emulsion. The 45 cP CEO-EC emulsion exhibited greatest antimicrobial activitiy in models with Escherichia coli (E. coli) O157:H7 (ATCC 700927) and Staphylococcus aureus (S. aureus) (ATCC 29213), as well as in sausage, with respect to total counts of mesophilic bacteria, psychrotrophs, lactobacilli, and pseudomonads. CONCLUSION: The CEO-EC oleogel has antibacterial activity, determined by the EC viscosity, that provide potential antibacterial protection for meat products and might be especially suitable for some traditional Chinese ready-to-eat sausages without strictly sealed packaging. © 2019 Society of Chemical Industry.


Assuntos
Antibacterianos/química , Celulose/análogos & derivados , Cinnamomum zeylanicum/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Óleos de Plantas/química , Antibacterianos/farmacologia , Celulose/química , Escherichia coli O157/efeitos dos fármacos , Escherichia coli O157/crescimento & desenvolvimento , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Compostos Orgânicos/química , Compostos Orgânicos/farmacologia , Óleos de Plantas/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Viscosidade
14.
Pharm Dev Technol ; 24(10): 1200-1209, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31343377

RESUMO

This article summarizes the critical factors involved in product development of a single dosage form formulated by compacting ethyl cellulose (EC) coated controlled release pellets into a tablet. The greatest challenge associated with this type of complex system is to minimize the effect of compression on the drug release. The effects of compression on the drug release were optimized with combination of the following factors (1) particle size of the core pellets, (2) the selection of the coating polymer's viscosity grade, and (3) emergence of cushioning agents. The optimization of these factors provided superior protection for the controlled release coated pellets; therefore, the desired drug release from the tablet was successfully achieved as designed. However, the drug release rates from the coated pellets before and after the compression were minimized and exhibited only a slight difference.


Assuntos
Celulose/análogos & derivados , Modelos Químicos , Preparações Farmacêuticas/química , Tecnologia Farmacêutica/métodos , Celulose/química , Preparações de Ação Retardada , Liberação Controlada de Fármacos , Solubilidade , Comprimidos
15.
AAPS PharmSciTech ; 20(6): 222, 2019 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-31214900

RESUMO

The aim of the work is to develop a data fusion model using near-infrared (NIR) and process parameters for the predictions of drug dissolution from controlled release multiparticulate beads. Using a design of experiments, ciprofloxacin-coated beads were manufactured and critical process parameters such as air volume, product temperature, curing temperature, and curing time were measured; environmental humidity was monitored using a Pyrobuttons®. The NIR spectra were decomposed using principal component analysis (PCA). The PCA scores were fused with process measurements and all variables were autoscaled. The autoscaled variables were regressed against measured dissolution data at 1 h and 2 h time points; the PLS regression used quadratic and cross terms. The NIR spectra only model using data collected at the end of bead curing generated a PLS model using 5 latent variables with R2 equal to 0.245 and 0.299 and RMSECV 13.23 and 13.12 for the 1 h and 2 h dissolution time points, respectively. The low R2 and high root mean square error of cross validation (RMSECV) values indicate that NIR spectra alone were insufficient to model the drug release. Similar results were obtained for NIR model using data collected at the end of spraying phase. Models with fused spectral and process data yielded better prediction with R2 above 0.88 and RMSECV less than 5% for the 1 h and 2 h dissolution time points. The data fusion model predicted dissolution profiles with an error less than 10%.


Assuntos
Antibacterianos/administração & dosagem , Antibacterianos/química , Ciprofloxacina/administração & dosagem , Ciprofloxacina/química , Preparações de Ação Retardada/química , Liberação Controlada de Fármacos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Umidade , Análise de Componente Principal , Temperatura
16.
Lipids Health Dis ; 17(1): 136, 2018 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-29885655

RESUMO

BACKGROUND: The study was to develop an extended release (ER) encapsulated and compacted pellets of Atenolol using hydrophobic (wax based and polymeric based) and high viscosity grade hydrophilic matrix formers to control the release of this highly water soluble drug by extrusion/spheronization (ES). Atenolol is used for cardiovascular diseases and available as an immediate release (IR) tablet dosage form. The lipids, Carnauba wax (CW), Glyceryl monostearate (GMS) and cellulose based i.e. Hydroxypropyl methylcellulose (HPMC) and Ethyl cellulose (EC) were used in preparing Atenolol ER pellets. Thermal sintering and compaction techniques were also applied to control the burst release of Atenolol. METHOD: For this purpose, thirty-six trial formulations (F1-F36) were designed by Response Surface Methodology (RSM), using Design-Expert 10 software, keeping (HPMC K4M, K15 M & K100 M), (EC 7FP, 10FP & 100FP), waxes (GMS, & CW), their combinations, sintering temperature and duration, as input variables. Dissolution studies were performed in pH, 1.2, 4.5 and 6.8 dissolution media. Drug release kinetics using different models such as zero order, first order, Korsmeyer-Peppas, Hixon Crowell, Baker-Lonsdale and Higuchi kinetics were studied with the help of DDsolver, an excel based add-in program. RESULTS: The formulations F35 and F36 showed compliance with Korsmeyer-Peppas Super case II transport model (R2 = 0.975-0.971) in dissolution medium pH 4.5. No drug excipient interaction observed by FTIR. Stereomicroscopy showed that sintered combination pellets, (F35), were highly spherical (AR = 1.061, and sphericity = 0.943). The cross-sectional SEM magnification (at 7000X) of F34 and F35 showed dense cross-linking. The results revealed that the optimized formulations were F35 (sintered pellets) and F36 (compacted pellets) effectively controlling the drug release for 12 h. CONCLUSION: Extended-release encapsulated, and compacted pellets were successfully prepared after the combination of lipids CW (10%) and GMS (20%) with EC (10FP 20% & 100FP 20%). Sintering and compaction, in addition, stabilized the system and controlled the initial burst release of the drug. Extended release (ER) Atenolol is an effective alternative of IR tablets in controlling hypertension and treating other cardiovascular diseases.


Assuntos
Anti-Hipertensivos/química , Atenolol/química , Celulose/análogos & derivados , Preparações de Ação Retardada/química , Glicerídeos/química , Ceras/química , Celulose/química , Química Farmacêutica , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos , Análise Fatorial , Humanos , Concentração de Íons de Hidrogênio , Cinética , Solubilidade , Soluções , Temperatura , Água/química
17.
Sensors (Basel) ; 18(9)2018 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-30200343

RESUMO

In this study, a quantitative analysis of nitrate in aqueous solution was performed through the combination of an oxazine170 perchlorate⁻ethyl cellulose (O17-EC) membrane with aluminum-containing compounds. Aluminum of Devarda's alloy (DA) or a clay hydrotalcite (HT) was employed for the reduction of nitrate to produce ammonia, and the produced ammonia was detected by the O17-EC membrane. The method of combining the O17-EC membrane with aluminum compounds has showed a broad detection range of nitrate. That is, the DA was combined with the O17-EC membrane and showed the linear nitrate detection ranges of 1⁻10 mM and 10⁻100 mM, while the O17-EC membrane immobilized with the clay HT showed a linear detection range of 0.1⁻1 mM nitrate. The visual color transition of the nitrate-sensing membranes at different nitrate concentrations was clearly observed under sunlight or irradiation of a light-emitting diode (LED) at an excitation wavelength of 470 nm (LED470).

18.
Drug Dev Ind Pharm ; 44(3): 421-431, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29098888

RESUMO

Plasticizers play a crucial role in various process of microencapsulation. In this study, the effect of incorporation of plasticizer in process of emulsion solvent evaporation was investigated on properties of ethyl cellulose (EC) microcapsules containing propranolol hydrochloride. The effect of plasticizer type and concentration were investigated on characteristics of microcapsules prepared from different viscosity grades of EC. Product yield, encapsulation efficiency, mean particle size, shape, surface characteristics, solid state of drug, and drug release profiles were evaluated. Product yield and encapsulation efficiency were not dependent on plasticizer type and concentration. However, encapsulation efficiency decreased with increase in EC viscosity grade in the most of the cases. The mean particle size was in the range of 724-797 µm and was not dependent on plasticizer type. Microcapsules formed in the presence of PEG had a very smooth surface with few pores. XRD and DSC studies revealed a reduction of drug crystallinity after microencapsulation especially in presence of PEG. The results showed that the presence of TEC and DEP with different concentrations had no marked effect on drug release from microcapsules containing different viscosity grades of EC. This was not the case when PEG was used, and despite its water solubility it reduced the drug release rate noticeably. The reduction in the drug release in the presence of PEG was concentration-dependent. The use of PEG as a plasticizer in process of emulsion solvent evaporation highly improved the EC microcapsule structure and retarded the drug release rate and therefore is recommended.


Assuntos
Cápsulas/química , Celulose/análogos & derivados , Citratos/química , Emulsões/química , Ácidos Ftálicos/química , Polietilenoglicóis/química , Propranolol/química , Celulose/química , Composição de Medicamentos/métodos , Tamanho da Partícula , Plastificantes/química , Solubilidade , Solventes/química , Viscosidade/efeitos dos fármacos
19.
AAPS PharmSciTech ; 19(2): 881-885, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29043605

RESUMO

Present study aims at solubilizing slightly water-soluble peptide into a nanosize emulsion which is filled into a hard gelatin capsule in the form of preconcentrate. Further, liquid-filled capsule was dip-coated with ethyl cellulose and Eudragit S100 for colon targeting. An in vitro release profile was studied for selected formulations, i.e., Formulation A (5 mg ethyl cellulose and 40 mg Eudragit S100), Formulation B (10 mg ethyl cellulose and 30 mg Eudragit S100), and Formulation C (10 mg ethyl cellulose and 20 mg Eudragit S100). Formulations B and A showed an immediate release after 5 and 6 h, respectively, which represents ileo-ceacal transit time. The nanosize of emulsion, i.e., below 100 nm, was confirmed by transmission electron microscopy. Also, a phase transition of nanosize emulsion from water in oil to oil in water on dilution with water was observed through TEM. This novel approach of filling poorly water-soluble protein in solubilized form of nanosize emulsion preconcentrate into coated hard gelatin capsules for colon targeting has been reported first time. This approach could be a breakthrough for the better management of local intestinal pathologies.


Assuntos
Química Farmacêutica/métodos , Colo , Sistemas de Liberação de Medicamentos/métodos , Imunossupressores/química , Peptídeos/química , Cápsulas , Colo/efeitos dos fármacos , Colo/metabolismo , Preparações de Ação Retardada/metabolismo , Emulsões , Imunossupressores/administração & dosagem , Imunossupressores/metabolismo , Peptídeos/administração & dosagem , Peptídeos/metabolismo , Ácidos Polimetacrílicos , Solubilidade , Comprimidos com Revestimento Entérico
20.
Pharm Dev Technol ; 22(6): 827-835, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27387408

RESUMO

OBJECTIVE: Wet agglomeration is a process wherein dispersed particles are held together in an aggregated form by the presence of a small quantity of solvent which acts as binder liquid. In this work, the efficiency of binder liquid was tested in the presence of various additives. METHODS: Solid state of carbamazepine (CBZ) agglomerates was characterized by DSC and FT-IR. The obtained agglomerates were also investigated in terms of yield, size distribution, friability, and drug release. RESULTS: CBZ agglomerates formed only in the presence of talc, span, and croscarmellose sodium (CCS), whereas ethyl cellulose and eudragit RS100 failed to make CBZ agglomerates. The presence of talc decreased the agglomerate size and produced CBZ agglomerates with a poor strength. However, span and CCS led to larger agglomerates with superior strength. In contrast to CCS samples, span and talc altered the dissolution rate of CBZ. FT-IR results showed that there is an interaction between CCS and drug. CONCLUSION: This study suggests that care must be taken when additives are used to manufacture agglomerates as the type of additives even in low concentrations can have a big impact on the efficiency of the binder liquid in forming agglomerates thereby affecting the quality of agglomerates.


Assuntos
Excipientes , Carbamazepina , Cristalização , Solventes , Espectroscopia de Infravermelho com Transformada de Fourier , Talco
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