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1.
AAPS PharmSciTech ; 25(2): 37, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38355916

RESUMO

Hot-melt extrusion (HME) is a globally recognized, robust, effective technology that enhances the bioavailability of poorly soluble active pharmaceutical ingredients and offers an efficient continuous manufacturing process. The twin-screw extruder (TSE) offers an extremely resourceful customizable mixer that is used for continuous compounding and granulation by using different combinations of conveying elements, kneading elements (forward and reverse configuration), and distributive mixing elements. TSE is thus efficiently utilized for dry, wet, or melt granulation not only to manufacture dosage forms such as tablets, capsules, or granule-filled sachets, but also for designing novel formulations such as dry powder inhalers, drying units for granules, nanoextrusion, 3D printing, complexation, and amorphous solid dispersions. Over the past decades, combined academic and pharmaceutical industry collaborations have driven novel innovations for HME technology, which has resulted in a substantial increase in published articles and patents. This article summarizes the challenges and models for executing HME scale-up. Additionally, it covers the benefits of continuous manufacturing, process analytical technology (PAT) considerations, and regulatory requirements. In summary, this well-designed review builds upon our earlier publication, probing deeper into the potential of twin-screw extruders (TSE) for various new applications.


Assuntos
Química Farmacêutica , Tecnologia Farmacêutica , Composição de Medicamentos/métodos , Tecnologia Farmacêutica/métodos , Química Farmacêutica/métodos , Tecnologia de Extrusão por Fusão a Quente , Indústria Farmacêutica/métodos , Temperatura Alta
2.
Expert Opin Drug Deliv ; 16(6): 567-582, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31046479

RESUMO

INTRODUCTION: Interest in hot-melt extrusion (HME) technology for novel applications is growing day by day, which is evident from several hundred publications within the last 5 years. HME is a cost-effective, solvent free, 'green' technology utilized for various formulations with low investment costs compared to conventional technologies. HME has also earned the attention of the pharmaceutical industry by the transformation of this technology for application in continuous manufacturing. AREAS COVERED: Part II of the review focuses on various novel opportunities or innovations of HME such as multiple component systems (co-crystals, co-amorphous systems and salts), twin-screw granulation, semi-solids, co-extrusion, abuse deterrent formulations, solid self-emulsifying drug delivery systems, chronotherapeutic drug delivery systems, and miscellaneous applications. EXPERT OPINION: HME is being investigated as an alternative technology for preparation of multicomponent systems such as co-crystals and co-amorphous techniques. Twin-screw granulation has gained increased interest in preparation of granules via twin-screw melt granulation or twin-screw dry granulation. This novel application of the HME process provides a promising alternate approach in the formulation of granules and solid dosage forms. However, this technology may need to be further investigated for scalability aspects of these novel applications for industrial production.


Assuntos
Composição de Medicamentos/métodos , Tecnologia de Extrusão por Fusão a Quente , Preparações Farmacêuticas/administração & dosagem , Indústria Farmacêutica , Temperatura Alta , Tecnologia Farmacêutica/métodos
3.
Expert Opin Drug Deliv ; 16(5): 539-550, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31007090

RESUMO

INTRODUCTION: Currently, hot melt extrusion (HME) is a promising technology in the pharmaceutical industry, as evidenced by its application to manufacture various FDA-approved commercial products in the market. HME is extensively researched for enhancing the solubility and bioavailability of poor water-soluble drugs, taste masking, and modifying release in drug delivery systems. Additionally, its other novel opportunities or pharmaceutical applications, and capability for continuous manufacturing are being investigated. This efficient, industrially scalable, solvent-free, continuous process can be easily automated and coupled with other novel platforms for continuous manufacturing of pharmaceutical products. AREAS COVERED: This review focuses on updates on solubility enhancement of poorly water-soluble drugs and process analytical tools such as UV/visible spectrophotometry; near-infrared spectroscopy; Raman spectroscopy; and rheometry for continuous manufacturing, with a special emphasis on fused deposition modeling 3D printing. EXPERT OPINION: The strengths, weakness, opportunities, threats (SWOT) and availability of commercial products confirmed wide HME applicability in pharmaceutical research. Increased interest in continuous manufacturing processes makes HME a promising strategy for this application. However, there is a need for extensive research using process analytical tools to establish HME as a dependable continuous manufacturing process.


Assuntos
Sistemas de Liberação de Medicamentos , Tecnologia de Extrusão por Fusão a Quente , Tecnologia Farmacêutica/métodos , Disponibilidade Biológica , Composição de Medicamentos , Indústria Farmacêutica/métodos , Preparações Farmacêuticas/química , Solubilidade , Análise Espectral Raman
4.
J Pharm Sci ; 108(9): 2895-2904, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30965041

RESUMO

Dry granulation is an indispensable process used to improve the flow property of moisture-sensitive materials. Considering the limitations of currently available dry granulation techniques, it is necessary to develop a novel technique. In this study, a twin-screw dry granulation (TSDG) technology was successfully applied to produce a sustained-release dry granule formulation, which was subsequently compressed into sustained-release tablets. Based on a preliminary study, theophylline was selected as model drug, Klucel™ EF, Ethocel™, and magnesium stearate were selected as excipients. A Resolution V Irregular Fraction Design was applied to determine the effect of different processing parameters (screw speed, feeding rate, barrel temperature, and screw configuration) on product properties (flow properties, particle size distribution, and dissolution time). A reliable model was achieved by combining the data obtained, and processing parameters were automatically optimized to attain the setting goal. In general, TSDG was demonstrated to be an alternative method for the preparation of dry granules. The continuous processing nature, simplicity of operation, and ease of optimization made TSDG competitive compared with other conventional dry granulation techniques.


Assuntos
Dessecação/métodos , Composição de Medicamentos/métodos , Excipientes/química , Teofilina/química , Química Farmacêutica/instrumentação , Química Farmacêutica/métodos , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Dessecação/instrumentação , Composição de Medicamentos/instrumentação , Liberação Controlada de Fármacos , Estudos de Viabilidade , Tamanho da Partícula , Solubilidade , Comprimidos , Temperatura , Resistência à Tração , Teofilina/farmacocinética
5.
Int J Pharm ; 555: 380-393, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30458256

RESUMO

Dry granulation is the preferred technique for solvent-sensitive products, especially drugs with stability problems such as hydrolysis. Twin-screw granulation is a continuous granulation technique, offering a potential alternative to conventional dry granulation techniques such as roller compaction. The major advantage of twin-screw granulation is the ability to adjust process parameters of dry granulation without compromising the compression properties. This study was aimed to perform exploratory studies of heat-assisted continuous twin-screw dry granulation process to formulate sustained release tablets for APIs with different melting points: theophylline, acetaminophen and lidocaine hydrochloride hydrate. Granulation feasibility was studied with different binders (e.g. Klucel™ EF, Kollidon® VA64), sustained release agents (e.g. Klucel™ MF, Eudragit® RSPO) and diluents at various drug loads. The processing conditions were below the melting point or glass transition temperature of the formulation ingredients. After successful granulation, DSC and XRD studies revealed the crystalline nature of the granules and FTIR studies showed no interaction of the API with the excipients. The granules were compressed into sustained release tablets without any compressibility issues. The tablets were stable after testing for 6 months at 25 °C/60% RH. This novel continuous dry granulation technique may offer an excellent alternative to conventional dry granulation techniques.


Assuntos
Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Excipientes/química , Tecnologia Farmacêutica/métodos , Acetaminofen/administração & dosagem , Acetaminofen/química , Varredura Diferencial de Calorimetria , Cristalização , Preparações de Ação Retardada , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Temperatura Alta , Lidocaína/administração & dosagem , Lidocaína/química , Comprimidos , Teofilina/administração & dosagem , Teofilina/química , Temperatura de Transição , Difração de Raios X
6.
Int J Pharm ; 519(1-2): 186-197, 2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-28017768

RESUMO

The main objective of this work was to explore the potential of coupling fused deposition modeling in three-dimensional (3D) printing with hot-melt extrusion (HME) technology to facilitate additive manufacturing, in order to fabricate tablets with enhanced extended release properties. Acetaminophen was used as the model drug and different grades and ratios of polymers were used to formulate tablets. Three-point bending and hardness tests were performed to determine the mechanical properties of the filaments and tablets. 3D-printed tablets, directly compressed mill-extruded tablets, and tablets prepared from a physical mixture were evaluated for drug release rates using a USP-II dissolution apparatus. The surface and cross-sectional morphology of the 3D-printed tablets were assessed by scanning electron microscopy. Differential scanning calorimetry and thermogravimetric analysis were used to characterize the crystal states and thermal properties of materials, respectively. The 3D-printed tablets had smooth surfaces and tight structures; therefore, they showed better extended drug release rates than the directly compressed tablets did. Further, this study clearly demonstrated the feasibility of coupling HME with 3D printing technology, which allows for the formulation of drug delivery systems using different grades and ratios of pharmaceutical polymers. In addition, formulations can be made based on the personal needs of patients.


Assuntos
Preparações de Ação Retardada/química , Comprimidos/química , Acetaminofen/química , Química Farmacêutica/métodos , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Polímeros/química , Impressão Tridimensional , Tecnologia Farmacêutica/métodos
7.
AAPS PharmSciTech ; 18(2): 341-348, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26573158

RESUMO

Developing a pediatric oral formulation with an age-appropriate dosage form and taste masking of naturally bitter active pharmaceutical ingredients (APIs) are key challenges for formulation scientists. Several techniques are used for taste masking of bitter APIs to improve formulation palatability; however, not all the techniques are applicable to pediatric dosage forms because of the limitations on the kind and concentration of the excipients that can be used. Hot-melt extrusion (HME) technology is used successfully for taste masking of bitter APIs and overcomes some of the limitations of the existing taste-masking techniques. Likewise, analytical taste assessment is an important quality control parameter evaluated by several in vivo and in vitro methods, such as the human taste panel, electrophysiological methods, electronic sensor, and animal preference tests to aid in selecting a taste-masked formulation. However, the most appropriate in vivo method to assess the taste-masking efficacy of pediatric formulations remains unknown because it is not known to what extent the human taste panel/electronic tongue can predict the palatability in the pediatric patients. The purpose of this study was to develop taste-masked caffeine citrate extrudates via HME and to demonstrate the wide applicability of a single bottle-test rat model to record and compare the volume consumed of the taste-masked solutions to that of the pure API. Thus, this rat model can be considered as a low-cost alternative taste-assessment method to the most commonly used expensive human taste panel/electronic tongue method for pediatric formulations.


Assuntos
Cafeína/administração & dosagem , Cafeína/química , Citratos/administração & dosagem , Citratos/química , Paladar/fisiologia , Administração Oral , Animais , Química Farmacêutica/métodos , Nariz Eletrônico , Excipientes/química , Humanos , Masculino , Pediatria , Controle de Qualidade , Ratos , Ratos Sprague-Dawley , Soluções/química , Tecnologia Farmacêutica/métodos
8.
Pharm Dev Technol ; 22(8): 1012-1016, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26740126

RESUMO

OBJECTIVE: To develop a fast dissolving film strip containing epinephrine HCl for the potential treatment of pediatric anaphylaxis. METHODS: Four different films have been prepared by solvent casting technique where the percentages of the polymer (Lycoat RS720) were optimized. The polymer percentages were (20%, 25%, 27% and 30%) of the total formulation weighs. The thickness and elastic modulus of the optimized film was evaluated using dynamic mechanical analyzer. Epinephrine content uniformity was assessed using UV at wavelength 280 nm. For the dissolution test, fast dissolving films (FDFs) were evaluated in 500 Simulated Saliva, with 50 rpm. In vivo taste and disintegration evaluation was performed on six healthy volunteers. RESULTS: Films formed by formulations 1, 2 and 3 were too sticky after drying, while formulation 4 that has 30% polymer content formed smooth, transparent, flexible and uniform film, and therefore, it was selected for further testing. The value of elastic modulus was determined at 1.325 MPa. The thickness of the film at different locations was measured at 0.29 mm. Drug content in film was measured at 93% ±10. More than 90% of epinephrine was released from the film within 7.2 min. Bitterness of epinephrine was masked efficiently according to volunteer's comments with average disintegration time of 20 s. CONCLUSION: This study presents potential proof for using FDFs as a replacement therapy of epinephrine injections for pediatrics.


Assuntos
Epinefrina , Anafilaxia/tratamento farmacológico , Química Farmacêutica , Criança , Humanos , Pediatria , Polímeros , Solubilidade
9.
J Mater Sci Mater Med ; 27(6): 103, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27091045

RESUMO

The objective of the current study was to formulate and characterize thermoreversible gel of Eletriptan Hydrobromide for brain targeting via the intranasal route. Ethosomes were prepared by 3(2) factorial design with two independent variables (concentration of soya lecithin and ethanol) and two response variables [percent entrapment efficiency and vesicle size (nm)] using ethanol injection method. Formulated ethosomes were evaluated for preliminary microscopic examination followed by percent drug entrapment efficiency, vesicle size analysis, zeta potential, polydispersibility index and Transmission electron microscopy (TEM). TEM confirms spherical morphology of ethosomes, whereas Malvern zeta sizer confirms that the vesicle size was in the range of 191 ± 6.55-381.3 ± 61.0 nm. Ethosomes were incorporated in gel using poloxamer 407 and carbopol 934 as thermoreversible and mucoadhesive polymers, respectively. Ethosomal gels were evaluated for their pH, viscosity, mucoadhesive strength, in vitro drug release and ex vivo drug permeation through the sheep nasal mucosa. Mucoadhesive strength and pH was found to be 4400 ± 45 to 5500 ± 78.10 dynes/cm(2) and 6.0 ± 0.3 to 6.2 ± 0.1, respectively. In-vitro drug release from the optimized ethosomal gel formulation (G4) was found to be almost 100 % and ex vivo permeation of 4980 µg/ml with a permeability coefficient of 11.94 ± 0.04 × 10(-5) cm/s after 24 h. Histopathological study of the nasal mucosa confirmed non-toxic nature of ethosomal gels. Formulated EH loaded ethosomal thermoreversible gel could serve as the better alternative for the brain targeting via the intranasal route which in turn could subsequently improve its bioavailability.


Assuntos
Nanoestruturas/química , Pirrolidinas/administração & dosagem , Triptaminas/administração & dosagem , Administração Intranasal , Animais , Géis/química , Microscopia Eletrônica de Transmissão , Mucosa Nasal , Pirrolidinas/química , Ovinos , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Triptaminas/química
10.
Expert Opin Drug Deliv ; 13(3): 451-64, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26886062

RESUMO

INTRODUCTION: Hot-melt extrusion (HME) technology is applied successfully in the plastic, rubber and food industry. HME has also emerged as an important technology for drug delivery applications in pharmaceutical research and manufacturing because of its process automation and low-cost scale-up properties, which reduce labor costs and capital investment. There are a number of commercial FDA-approved HME-derived products, signifying the commercial feasibility of this novel technique in drug delivery applications. HME is a highly efficient, solvent-free continuous processing technique for the development of solid dispersions; thus, research efforts to develop sustained, modified and targeted drug delivery systems to improve the solubility and bioavailability of poorly water-soluble active pharmaceutical ingredients (APIs) are of interest. AREAS COVERED: This review focuses on both the innovations and applications of HME in the production of pharmaceutical formulations, and on the significant findings of the general principles regarding formulation and process development via HME as described in published articles. EXPERT OPINION: Challenges faced by pharmaceutical companies to produce efficient drug formulations may be partly overcome by HME's advantages - high drug-loading capacity, good content uniformity, cost-effectiveness, and ease of processing scale-up. Nevertheless, HME's high processing temperatures may be an obstacle if adequate knowledge about the product's formulation is lacking.


Assuntos
Sistemas de Liberação de Medicamentos , Preparações Farmacêuticas/administração & dosagem , Tecnologia Farmacêutica/métodos , Disponibilidade Biológica , Química Farmacêutica/métodos , Temperatura Alta , Solubilidade
11.
J Pharm Pharmacol ; 68(5): 692-704, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26589107

RESUMO

OBJECTIVE: The aim of this study was to evaluate the effect of polymer carrier, hot melt extrusion and downstream processing parameters on the water uptake properties of amorphous solid dispersions. METHODS: Three polymers and a model drug were used to prepare amorphous solid dispersions utilizing the hot melt extrusion technology. The sorption-desorption isotherms of solid dispersions and their physical mixtures were measured by the dynamic vapour sorption system, and the effects of polymer hydrophobicity, hygroscopicity, molecular weight and the hot melt extrusion process were investigated. Fourier transform infrared (FTIR) imaging was performed to understand the phase separation driven by the moisture. KEY FINDINGS: Solid dispersions with polymeric carriers with lower hydrophilicity, hygroscopicity and higher molecular weight could sorb less moisture under the high relative humidity (RH) conditions. The water uptake ability of polymer-drug solid dispersion systems were decreased compared with the physical mixture after hot melt extrusion, which might be due to the decreased surface area and porosity. The FTIR imaging indicated that the homogeneity of the drug molecularly dispersed within the polymer matrix was changed after exposure to high RH. CONCLUSION: Understanding the effect of formulation and processing on the moisture sorption properties of solid dispersions is essential for the development of drug products with desired physical and chemical stability.


Assuntos
Fenofibrato/química , Temperatura Alta , Polímeros/química , Tecnologia Farmacêutica/métodos , Água/química , Absorção Fisico-Química , Celulose/análogos & derivados , Celulose/química , Composição de Medicamentos , Interações Hidrofóbicas e Hidrofílicas , Peso Molecular , Polietilenoglicóis/química , Espectroscopia de Infravermelho com Transformada de Fourier , Molhabilidade
12.
Drug Dev Ind Pharm ; 42(6): 906-15, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26472165

RESUMO

Commercially available domperidone orodispersible tablets (ODT) are intended for immediate release of the drug, but none of them have been formulated for sustained action. The aim of the present research work was to develop and evaluate orodispersible sustained release tablet (ODT-SR) of domperidone, which has the convenience of ODT and benefits of controlled release product combined in one. The technology comprised of developing sustained release microspheres (MS) of domperidone, followed by direct compression of MS along with suitable excipients to yield ODT-SR which rapidly disperses within 30 seconds and yet the dispersed MS maintain their integrity to have a sustained drug release. The particle size of the MS was optimized to be less than 200 µm to avoid the grittiness in the mouth. The DSC thermograms of MS showed the absence of drug-polymer interaction within the microparticles, while SEM confirmed their spherical shape and porous nature. Angle of repose, compressibility and Hausner's ratio of the blend for compression showed good flowability and high percent compressibility. The optimized ODT-SR showed disintegration time of 21 seconds and matrix controlled drug release for 9 h. In-vivo pharmacokinetic studies in Wistar rats showed that the ODT-SR had a prolonged MRT of 11.16 h as compared 3.86 h of conventional tablet. The developed technology is easily scalable and holds potential for commercial exploitation.


Assuntos
Preparações de Ação Retardada/química , Domperidona/química , Comprimidos/química , Administração Oral , Animais , Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos , Excipientes/química , Dureza , Microesferas , Tamanho da Partícula , Polímeros/química , Ratos , Ratos Wistar
13.
AAPS PharmSciTech ; 17(1): 78-88, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26283197

RESUMO

Over the past few decades, nanocrystal formulations have evolved as promising drug delivery systems owing to their ability to enhance the bioavailability and maintain the stability of poorly water-soluble drugs. However, conventional methods of preparing nanocrystal formulations, such as spray drying and freeze drying, have some drawbacks including high cost, time and energy inefficiency, traces of residual solvent, and difficulties in continuous operation. Therefore, new techniques for the production of nanocrystal formulations are necessary. The main objective of this study was to introduce a new technique for the production of nanocrystal solid dispersions (NCSDs) by combining high-pressure homogenization (HPH) and hot-melt extrusion (HME). Efavirenz (EFZ), a Biopharmaceutics Classification System class II drug, which is used for the treatment of human immunodeficiency virus (HIV) type I, was selected as the model drug for this study. A nanosuspension (NS) was first prepared by HPH using sodium lauryl sulfate (SLS) and Kollidon® 30 as a stabilizer system. The NS was then mixed with Soluplus® in the extruder barrel, and the water was removed by evaporation. The decreased particle size and crystalline state of EFZ were confirmed by scanning electron microscopy, zeta particle size analysis, and differential scanning calorimetry. The increased dissolution rate was also determined. EFZ NCSD was found to be highly stable after storage for 6 months. In summary, the conjugation of HPH with HME technology was demonstrated to be a promising novel method for the production of NCSDs.


Assuntos
Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Nanopartículas/química , Alcinos , Benzoxazinas/química , Varredura Diferencial de Calorimetria/métodos , Ciclopropanos , Portadores de Fármacos/química , Estabilidade de Medicamentos , Liofilização/métodos , Temperatura Alta , Tamanho da Partícula , Polietilenoglicóis/química , Polivinil/química , Povidona/química , Solubilidade , Suspensões/química , Água/química
14.
AAPS PharmSciTech ; 17(1): 20-42, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26159653

RESUMO

Hot-melt extrusion (HME) is a promising technology for the production of new chemical entities in the developmental pipeline and for improving products already on the market. In drug discovery and development, industry estimates that more than 50% of active pharmaceutical ingredients currently used belong to the biopharmaceutical classification system II (BCS class II), which are characterized as poorly water-soluble compounds and result in formulations with low bioavailability. Therefore, there is a critical need for the pharmaceutical industry to develop formulations that will enhance the solubility and ultimately the bioavailability of these compounds. HME technology also offers an opportunity to earn intellectual property, which is evident from an increasing number of patents and publications that have included it as a novel pharmaceutical formulation technology over the past decades. This review had a threefold objective. First, it sought to provide an overview of HME principles and present detailed engineered extrusion equipment designs. Second, it included a number of published reports on the application of HME techniques that covered the fields of solid dispersions, microencapsulation, taste masking, targeted drug delivery systems, sustained release, films, nanotechnology, floating drug delivery systems, implants, and continuous manufacturing using the wet granulation process. Lastly, this review discussed the importance of using the quality by design approach in drug development, evaluated the process analytical technology used in pharmaceutical HME monitoring and control, discussed techniques used in HME, and emphasized the potential for monitoring and controlling hot-melt technology.


Assuntos
Química Farmacêutica/métodos , Preparações Farmacêuticas/química , Tecnologia Farmacêutica/métodos , Disponibilidade Biológica , Sistemas de Liberação de Medicamentos/métodos , Indústria Farmacêutica/métodos , Desenho de Equipamento/métodos , Temperatura Alta , Solubilidade
15.
AAPS PharmSciTech ; 17(1): 158-66, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26628438

RESUMO

Ointments are generally prepared either by fusion or by levigation methods. The current study proposes the use of hot-melt extrusion (HME) processing for the preparation of a polyethylene glycol base ointment. Lidocaine was used as a model drug. A modified screw design was used in this process, and parameters such as feeding rate, barrel temperature, and screw speed were optimized to obtain a uniform product. The product characteristics were compared with an ointment of similar composition prepared by conventional fusion method. The rheological properties, drug release profile, and texture characteristics of the hot-melt extruded product were similar to the conventionally prepared product. This study demonstrates a novel application of the hot-melt extrusion process in the manufacturing of topical semi-solids.


Assuntos
Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Pomadas/química , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Temperatura Alta , Reologia
16.
Molecules ; 20(12): 21787-801, 2015 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-26690103

RESUMO

Through the incorporation of a thiophene functionality, a novel solution-processable small organic chromophore was designed, synthesized and characterized for application in bulk-heterojunction solar cells. The new chromophore, (2Z,2'Z)-2,2'-(1,4-phenylene)bis(3-(5-(4-(diphenylamino)phenyl)thiophen-2-yl)acrylonitrile) (coded as AS2), was based on a donor-acceptor-donor (D-A-D) module where a simple triphenylamine unit served as an electron donor, 1,4-phenylenediacetonitrile as an electron acceptor, and a thiophene ring as the π-bridge embedded between the donor and acceptor functionalities. AS2 was isolated as brick-red, needle-shaped crystals, and was fully characterized by ¹H- and (13)C-NMR, IR, mass spectrometry and single crystal X-ray diffraction. The optoelectronic and photovoltaic properties of AS2 were compared with those of a structural analogue, (2Z,2'Z)-2,2'-(1,4-phenylene)bis(3-(4-(diphenylamino)phenyl)-acrylonitrile) (AS1). Benefiting from the covalent thiophene bridges, compared to AS1 thin solid film, the AS2 film showed: (1) an enhancement of light-harvesting ability by 20%; (2) an increase in wavelength of the longest wavelength absorption maximum (497 nm vs. 470 nm) and (3) a narrower optical band-gap (1.93 eV vs. 2.17 eV). Studies on the photovoltaic properties revealed that the best AS2-[6,6]-phenyl-C61-butyric acid methyl ester (PC61BM)-based device showed an impressive enhanced power conversion efficiency of 4.10%, an approx. 3-fold increase with respect to the efficiency of the best AS1-based device (1.23%). These results clearly indicated that embodiment of thiophene functionality extended the molecular conjugation, thus enhancing the light-harvesting ability and short-circuit current density, while further improving the bulk-heterojunction device performance. To our knowledge, AS2 is the first example in the literature where a thiophene unit has been used in conjunction with a 1,4-phenylenediacetonitrile accepting functionality to extend the π-conjugation in a given D-A-D motif for bulk-heterojunction solar cell applications.


Assuntos
Corantes/química , Tiofenos/química , Cristalografia por Raios X , Eletroquímica , Processos Fotoquímicos , Energia Solar , Soluções
17.
Molecules ; 20(9): 17362-77, 2015 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-26393566

RESUMO

Two solution-processable small organic molecules, (E)-6,6'-bis(4-(diphenylamino)phenyl)-1,1'-bis(2-ethylhexyl)-(3,3'-biindolinylidene)-2,2'-dione (coded as S10) and (E)-6,6'-di(9H-carbazol-9-yl)-1,1'-bis(2-ethylhexyl)-(3,3'-biindolinylidene)-2,2'-dione (coded as S11) were successfully designed, synthesized and fully characterized. S10 and S11 are based on a donor-acceptor-donor structural motif and contain a common electron accepting moiety, isoindigo, along with different electron donating functionalities, triphenylamine and carbazole, respectively. Ultraviolet-visible absorption spectra revealed that the use of triphenylamine donor functionality resulted in an enhanced intramolecular charge transfer transition and reduction of optical band gap, when compared with its carbazole analogue. Both of these materials were designed to be donor semiconducting components, exerted excellent solubility in common organic solvents, showed excellent thermal stability, and their promising optoelectronic properties encouraged us to scrutinize charge-carrier mobilities using solution-processable organic field effect transistors. Hole mobilities of the order of 2.2 × 10(-4) cm²/Vs and 7.8 × 10(-3) cm²/Vs were measured using S10 and S11 as active materials, respectively.


Assuntos
Indóis/química , Indóis/síntese química , Aminas/química , Carbazóis/química , Estrutura Molecular , Semicondutores
18.
Int J Pharm ; 496(1): 33-41, 2015 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-25863118

RESUMO

The objective of the present study was to develop pH-independent/dependent sustained release (SR) tablets of ondansetron HCl dihydrate (OND), a selective 5-HT3 receptor antagonist that is used for prevention of nausea and vomiting caused by chemotherapy, radiotherapy and postoperative treatment. The challenge with the OND API is its pH-dependent solubility and relatively short elimination half-life. Therefore, investigations were made to solve these problems in the current study. Formulations were prepared using stearic acid as a binding agent via a melt granulation process in a twin-screw extruder. The micro-environmental pH of the tablet was manipulated by the addition of fumaric acid to enhance the solubility and release of OND from the tablet. The in vitro release study demonstrated sustained release for 24h with 90% of drug release in formulations using stearic acid in combination with ethyl cellulose, whereas 100% drug release in 8h for stearic acid-hydroxypropylcellulose matrices. The formulation release kinetics was correlated to the Higuchi diffusion model and a non-Fickian drug release mechanism. The results of the present study demonstrated for the first time the pH dependent release from hydrophilic-lipid matrices as well as pH independent release from hydrophobic-lipid matrices for OND SR tablets manufactured by means of a continuous melt granulation technique utilizing a twin-screw extruder.


Assuntos
Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Excipientes/química , Ondansetron/administração & dosagem , Celulose/análogos & derivados , Celulose/química , Preparações de Ação Retardada , Liberação Controlada de Fármacos , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Cinética , Ondansetron/química , Antagonistas da Serotonina/administração & dosagem , Antagonistas da Serotonina/química , Solubilidade , Ácidos Esteáricos/química , Comprimidos , Tecnologia Farmacêutica/métodos
19.
J Org Chem ; 80(8): 3832-40, 2015 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-25822257

RESUMO

Supramolecular self-assembly and self-organization are simple and convenient ways to design and create controlled assemblies with organic molecules, and they have provoked great interest due to their potential applications in various fields, such as electronics, photonics, and light-energy conversion. Herein, we describe the synthesis of two π-conjugated porphyrin molecules bearing tetraphenylethene moieties with high fluorescence quantum yield. Photophysical and electrochemical studies were conducted to understand the physical and redox properties of these new materials, respectively. Furthermore, these derivatives were used to investigate self-assembly via the solvophobic effect. The self-assembled aggregation was performed in nonpolar and polar organic solvents and forms nanospheres and ring-like nanostructures, respectively. The solution based aggregation was studied by means of UV-vis absorption, emission, XRD, and DLS analyses. Self-assembled ring-shape structures were visualized by SEM and TEM imaging. This ring-shape morphology of nanosized macromolecules might be a good candidate for the creation of artificial light-harvesting nanodevices.

20.
AAPS J ; 17(1): 194-205, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25344439

RESUMO

This contribution describes a continuous process for the production of solid lipid nanoparticles (SLN) as drug-carrier systems via hot-melt extrusion (HME). Presently, HME technology has not been used for the manufacturing of SLN. Generally, SLN are prepared as a batch process, which is time consuming and may result in variability of end-product quality attributes. In this study, using Quality by Design (QbD) principles, we were able to achieve continuous production of SLN by combining two processes: HME technology for melt-emulsification and high-pressure homogenization (HPH) for size reduction. Fenofibrate (FBT), a poorly water-soluble model drug, was incorporated into SLN using HME-HPH methods. The developed novel platform demonstrated better process control and size reduction compared to the conventional process of hot homogenization (batch process). Varying the process parameters enabled the production of SLN below 200 nm. The dissolution profile of the FBT SLN prepared by the novel HME-HPH method was faster than that of the crude FBT and a micronized marketed FBT formulation. At the end of a 5-h in vitro dissolution study, a SLN formulation released 92-93% of drug, whereas drug release was approximately 65 and 45% for the marketed micronized formulation and crude drug, respectively. Also, pharmacokinetic study results demonstrated a statistical increase in Cmax, Tmax, and AUC0-24 h in the rate of drug absorption from SLN formulations as compared to the crude drug and marketed micronized formulation. In summary, the present study demonstrated the potential use of hot-melt extrusion technology for continuous and large-scale production of SLN.


Assuntos
Portadores de Fármacos/química , Fenofibrato/administração & dosagem , Lipídeos/química , Nanopartículas , Animais , Área Sob a Curva , Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Fenofibrato/química , Fenofibrato/farmacocinética , Temperatura Alta , Hipolipemiantes/administração & dosagem , Hipolipemiantes/química , Hipolipemiantes/farmacocinética , Masculino , Tamanho da Partícula , Ratos , Ratos Wistar , Solubilidade , Tecnologia Farmacêutica/métodos
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