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1.
Radiology ; 311(3): e232653, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38888474

RESUMEN

The deployment of artificial intelligence (AI) solutions in radiology practice creates new demands on existing imaging workflow. Accommodating custom integrations creates a substantial operational and maintenance burden. These custom integrations also increase the likelihood of unanticipated problems. Standards-based interoperability facilitates AI integration with systems from different vendors into a single environment by enabling seamless exchange between information systems in the radiology workflow. Integrating the Healthcare Enterprise (IHE) is an initiative to improve how computer systems share information across health care domains, including radiology. IHE integrates existing standards-such as Digital Imaging and Communications in Medicine, Health Level Seven, and health care lexicons and ontologies (ie, LOINC, RadLex, SNOMED Clinical Terms)-by mapping data elements from one standard to another. IHE Radiology manages profiles (standards-based implementation guides) for departmental workflow and information sharing across care sites, including profiles for scaling AI processing traffic and integrating AI results. This review focuses on the need for standards-based interoperability to scale AI integration in radiology, including a brief review of recent IHE profiles that provide a framework for AI integration. This review also discusses challenges and additional considerations for AI integration, including technical, clinical, and policy perspectives.


Asunto(s)
Inteligencia Artificial , Sistemas de Información Radiológica , Integración de Sistemas , Flujo de Trabajo , Radiología/normas , Sistemas de Información Radiológica/normas
2.
Biomacromolecules ; 19(11): 4430-4441, 2018 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-30350598

RESUMEN

A new family of cellulosic ether polymeric excipients has been recently engineered for fabrication of amorphous solid dispersions of active pharmaceutical ingredients via hot-melt extrusion (HME). These hydroxypropyl methyl cellulose excipients enable plasticizer-free melt processing at much lower temperatures (135-160 °C) due to their substantially reduced glass transition temperatures ( Tg = 98-110 °C). The novel amorphous cellulose ethers were found to be rheologically solidlike well above their glass transition ( Tg + 70 °C). We demonstrate that in the pharmaceutically relevant HME processing temperature range these polymers behave similarly to yield-stress fluids and flow only when the applied stress exceeds a critical stress value. This critical stress value (0.50 ± 0.05 MPa, 150 °C) is surprisingly high but is easily achieved under typical HME conditions. The origin of their yield-stress fluidlike behavior is hypothesized to arise from hydrogen bonds of the HPMC materials that act as physical cross-links and do not relax within the measured temperature and time window unless the applied stress exceeds the critical stress value. Support for this hypothesis arises from infrared spectroscopic estimates of the free and bound hydrogen bond levels at end-use temperatures.


Asunto(s)
Celulosa/química , Portadores de Fármacos/química , Éter/química , Excipientes/química , Calor , Plastificantes/química , Polímeros/química , Preparaciones Farmacéuticas/química , Reología
3.
Materials (Basel) ; 11(10)2018 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-30248983

RESUMEN

Europium is the most-studied and least-well-understood rare earth ion (REI) dopant in GaN. While attempting to increase the efficiency of red GaN light-emitting diodes (LEDs) by implanting Eu⁺ into p-type GaN templates, the Strathclyde University group, in collaboration with IST Lisbon and Unipress Warsaw, discovered hysteretic photochromic switching (HPS) in the photoluminescence spectrum of doubly doped GaN(Mg):Eu. Our recent work, summarised in this contribution, has used time-, temperature- and light-induced changes in the Eu intra-4f shell emission spectrum to deduce the microscopic nature of the Mg-Eu defects that form in this material. As well as shedding light on the Mg acceptor in GaN, we propose a possible role for these emission centres in quantum information and computing.

4.
J Thorac Cardiovasc Surg ; 154(6): 2144-2151.e1, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-28942970

RESUMEN

OBJECTIVE: The immunosuppressive efficacy of inhaled nanoparticle tacrolimus was compared with systemic tacrolimus in a rodent allogeneic lung transplant model. METHODS: Sixteen rats underwent allogeneic left orthotopic lung transplantation and were divided into 3 treatment groups: (1) inhaled nanoparticle tacrolimus: 6.4 mg tacrolimus/6.4 mg lactose twice per day; (2) intramuscular tacrolimus: 1 mg/kg tacrolimus once per day; and (3) inhaled lactose: 6.4 mg of lactose twice per day. Five days after transplant, the rats were necropsied and underwent histologic rejection grading and cytokine analysis. Trough levels of tacrolimus were measured in allograft, blood, and kidney. RESULTS: Both intramuscular (n = 6) and nanoparticle tacrolimus (n = 6) rats displayed lower histologic grades of rejection (mean scores 3.4 ± 0.6 and 4.6 ± 0.9, respectively) when compared with lactose rats (n = 4) (mean score 11.38 ± 0.5, P = .07). Systemic tacrolimus trough levels (median) were lower in nanoparticle tacrolimus-treated rats versus intramuscular-treated rats (29.2 vs 118.6 ng/g; P < .001 in kidney, and 1.5 vs 4.8 ng/mL; P = .01 in blood). CONCLUSIONS: Inhaled nanoparticle tacrolimus provided similar efficacy in preventing acute rejection when compared with systemic tacrolimus while maintaining lower systemic levels.


Asunto(s)
Inhibidores de la Calcineurina/administración & dosificación , Rechazo de Injerto/prevención & control , Inmunosupresores/administración & dosificación , Trasplante de Pulmón/efectos adversos , Nanopartículas , Tacrolimus/administración & dosificación , Administración por Inhalación , Aloinjertos , Animales , Inhibidores de la Calcineurina/sangre , Inhibidores de la Calcineurina/química , Inhibidores de la Calcineurina/farmacocinética , Citocinas/sangre , Modelos Animales de Enfermedad , Composición de Medicamentos , Rechazo de Injerto/sangre , Rechazo de Injerto/inmunología , Inmunosupresores/sangre , Inmunosupresores/química , Inmunosupresores/farmacocinética , Inyecciones Intramusculares , Lactosa/química , Masculino , Ratas Endogámicas BN , Ratas Endogámicas Lew , Tacrolimus/sangre , Tacrolimus/química , Tacrolimus/farmacocinética
5.
Eur J Pharm Biopharm ; 119: 56-67, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28583588

RESUMEN

The formation of molecularly dispersed amorphous solid dispersions by the hot-melt extrusion technique relies on the thermal and mechanical energy inputs, which can cause chemical degradation of drugs and polymeric carriers. Additionally, drug degradation may be exacerbated as drugs convert from a more stable crystalline form to a higher energy amorphous form. Therefore, it is imperative to study how drug degrades and evaluate methods to minimize drug degradation during the extrusion process. In this work, gliclazide was used as a model thermally labile drug for the degradation kinetics and process optimization studies. Preformulation studies were conducted using thermal analyses, and liquid chromatography-mass spectroscopy to identify drug degradation pathways and to determine initial extrusion conditions. Formulations containing 10% drug and 90% AFFINISOL™ HPMC HME 100LV were then extruded using a twin screw extruder, and the extrudates were characterized using X-ray powder diffraction, modulated dynamic scanning calorimetry, and potency testing to evaluate physicochemical properties. The energies of activation for both amorphous gliclazide, crystalline gliclazide, and gliclazide solution were calculated using the Arrhenius equation to further guide the extrusion optimization process. Preformulation studies identify two hydrolysis degradation pathways of gliclazide at elevated temperatures. The activation energy study indicates a significantly higher degradation rate for the amorphous gliclazide compared to the crystalline form. After optimization of the hot-melt extrusion process, including improved screw designs, machine setup, and processing conditions, gliclazide amorphous solid dispersion with ∼95% drug recovery was achieved. The ability to process thermally labile drugs and polymers using hot-melt extrusion will significantly expand the possible applications of this manufacturing process.


Asunto(s)
Química Farmacéutica/métodos , Gliclazida/análisis , Gliclazida/síntesis química , Calor , Rastreo Diferencial de Calorimetría/métodos , Termogravimetría/métodos , Difracción de Rayos X/métodos
6.
AAPS PharmSciTech ; 17(1): 106-19, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26335416

RESUMEN

Hypromellose is a hydrophilic polymer widely used in immediate- and modified-release oral pharmaceutical dosage forms. However, currently available grades of hypromellose are difficult, if not impossible, to process by hot melt extrusion (HME) because of their high glass transition temperature, high melt viscosity, and low degradation temperature. To overcome these challenges, a modified grade of hypromellose, AFFINISOL™ HPMC HME, was recently introduced. It has a significantly lower glass transition temperature and melt viscosity as compared to other available grades of hypromellose. The objective of this paper is to assess the extrudability and performance of AFFINISOL™ HPMC HME (100LV and 4M) as compared to other widely used polymers in HME, including HPMC 2910 100cP (the currently available hypromellose), Soluplus®, Kollidon® VA 64, and EUDRAGIT® E PO. Formulations containing polymer and carbamazepine (CBZ) were extruded on a co-rotating 16-mm twin-screw extruder, and the effect of temperature, screw speed, and feed rate was investigated. The performance of the solid dispersions was evaluated based on Flory-Huggins modeling and characterized by differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), Raman spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and dissolution. All formulations extruded well except for HPMC 2910 100cP, which resulted in over-torqueing the extruder (machine overloading because the motor cannot provide efficient energy to rotate the shaft). Among the HME extrudates, only the EUDRAGIT® E PO formulation was crystalline as confirmed by DSC, XRD, and Raman, which agreed with predictions from Flory-Huggins modeling. Dissolution testing was conducted under both sink and non-sink conditions. Sink dissolution testing in neutral media revealed that amorphous CBZ in the HME extrudates completely dissolved within 15 min, which was much more rapid than the time for complete dissolution of bulk CBZ (60 min) and EUDRAGIT® E PO solid dispersion (more than 6 h). Non-sink dissolution in acidic media testing revealed that only CBZ contained in the AFFINISOL™ HPMC HME, and EUDRAGIT® E PO solid dispersions rapidly supersaturated after 15 min, reaching a twofold drug concentration compared to the CBZ equilibrium solubility. In summary, AFFINISOL™ HPMC HME 100LV and AFFINISOL™ HPMC HME 4M are useful in the pharmaceutical HME process to increase wetting and dissolution properties of poorly water-soluble drugs like CBZ.


Asunto(s)
Química Farmacéutica/métodos , Derivados de la Hipromelosa/química , Polímeros/química , Rastreo Diferencial de Calorimetría/métodos , Carbamazepina/química , Composición de Medicamentos/métodos , Calor , Polietilenglicoles/química , Ácidos Polimetacrílicos/química , Polivinilos/química , Povidona/química , Polvos/química , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Viscosidad , Agua/química , Difracción de Rayos X/métodos
7.
Orthopedics ; 38(10): e904-10, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26488786

RESUMEN

Anatomic total shoulder arthroplasty (TSA) and reverse total shoulder arthroplasty (RSA) are routinely performed in patients older than 80 years. Often unaware of the differences between the 2 procedures, patients may expect similar outcomes from these procedures. This article reports the outcomes of primary TSA and RSA in patients older than 80 years, with attention directed toward differences in outcomes between the procedures. The authors evaluated a consecutive series of patients who were at least 80 years old and were treated with primary shoulder arthroplasty and had a minimum follow-up of 2 years. Of these patients, 18 underwent primary TSA for osteoarthritis and 33 underwent primary RSA for rotator cuff tear arthropathy. Pain scores, function scores, and range of motion were evaluated preoperatively and at final follow-up. Perioperative and postoperative complications, transfusion rates, length of stay, and subjective satisfaction with the outcome were reported. In these patients, TSA and RSA were similarly effective in improving pain scores, functional scores, and range of motion measurements. Patients who had TSA reported significantly greater satisfaction with surgery and had superior American Shoulder and Elbow Society total and function scores, forward elevation, and external rotation, but similar net improvement from preoperative levels. Although no significant differences were shown in complications, length of stay, or requirement for transfusion, patients treated with RSA had higher rates of transfusion and postoperative complications. Both procedures were similarly effective treatments for patients older than 80 years and showed similar improvements in pain, function, and motion. Patients undergoing RSA were less likely to have good to excellent results, with higher complication and transfusion rates.


Asunto(s)
Artroplastia de Reemplazo/métodos , Osteoartritis/cirugía , Rango del Movimiento Articular , Lesiones del Manguito de los Rotadores , Articulación del Hombro/cirugía , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Estudios Retrospectivos , Rotación , Resultado del Tratamiento
8.
Microsc Microanal ; 21(4): 994-1005, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26123063

RESUMEN

We present a simple and robust method to acquire quantitative maps of compositional fluctuations in nanostructures from low magnification high-angle annular dark field (HAADF) micrographs calibrated by energy-dispersive X-ray (EDX) spectroscopy in scanning transmission electron microscopy (STEM) mode. We show that a nonuniform background in HAADF-STEM micrographs can be eliminated, to a first approximation, by use of a suitable analytic function. The uncertainty in probe position when collecting an EDX spectrum renders the calibration of HAADF-STEM micrographs indirect, and a statistical approach has been developed to determine the position with confidence. Our analysis procedure, presented in a flowchart to facilitate the successful implementation of the method by users, was applied to discontinuous InGaN/GaN quantum wells in order to obtain quantitative determinations of compositional fluctuations on the nanoscale.

9.
Sci Rep ; 5: 9703, 2015 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-25853988

RESUMEN

We studied the optical properties of metalorganic chemical vapour deposited (MOCVD) InGaN/GaN multiple quantum wells (MQW) subjected to nitrogen (N) implantation and post-growth annealing treatments. The optical characterization was carried out by means of temperature and excitation density-dependent steady state photoluminescence (PL) spectroscopy, supplemented by room temperature PL excitation (PLE) and PL lifetime (PLL) measurements. The as-grown and as-implanted samples were found to exhibit a single green emission band attributed to localized excitons in the QW, although the N implantation leads to a strong reduction of the PL intensity. The green band was found to be surprisingly stable on annealing up to 1400°C. A broad blue band dominates the low temperature PL after thermal annealing in both samples. This band is more intense for the implanted sample, suggesting that defects generated by N implantation, likely related to the diffusion/segregation of indium (In), have been optically activated by the thermal treatment.

10.
Drug Dev Ind Pharm ; 41(3): 382-97, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24329130

RESUMEN

Acetyl-11-keto-ß-boswellic acid (AKBA), a gum resin extract, possesses poor water-solubility that limits bioavailability and a high melting point making it difficult to successfully process into solid dispersions by fusion methods. The purpose of this study was to investigate solvent and thermal processing techniques for the preparation of amorphous solid dispersions (ASDs) exhibiting enhanced solubility, dissolution rates and bioavailability. Solid dispersions were successfully produced by rotary evaporation (RE) and KinetiSol® Dispersing (KSD). Solid state and chemical characterization revealed that ASD with good potency and purity were produced by both RE and KSD. Results of the RE studies demonstrated that AQOAT®-LF, AQOAT®-MF, Eudragit® L100-55 and Soluplus with the incorporation of dioctyl sulfosuccinate sodium provided substantial solubility enhancement. Non-sink dissolution analysis showed enhanced dissolution properties for KSD-processed solid dispersions in comparison to RE-processed solid dispersions. Variances in release performance were identified when different particle size fractions of KSD samples were analyzed. Selected RE samples varying in particle surface morphologies were placed under storage and exhibited crystalline growth following solid-state stability analysis at 12 months in comparison to stored KSD samples confirming amorphous instability for RE products. In vivo analysis of KSD-processed solid dispersions revealed significantly enhanced AKBA absorption in comparison to the neat, active substance.


Asunto(s)
Química Farmacéutica/métodos , Olíbano/síntesis química , Gomas de Plantas/síntesis química , Triterpenos/síntesis química , Agua/química , Animales , Olíbano/metabolismo , Masculino , Gomas de Plantas/metabolismo , Ratas , Ratas Sprague-Dawley , Solubilidad , Triterpenos/metabolismo , Agua/metabolismo , Difracción de Rayos X
11.
Drug Dev Ind Pharm ; 41(6): 959-68, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24842545

RESUMEN

The purpose of this study was to evaluate analytical techniques for the measurement of the glass transition temperature of HPMC and formulated solid dispersions thereof. Unmodified samples of various grades of HPMC and solid dispersions of HPMC and itraconazole produced by hot melt extrusion were analyzed by thermomechanical analysis, differential scanning calorimetry, thermally stimulated depolarization current and dielectric spectroscopy. It was found that dielectric spectroscopy offers the best accuracy and reproducibility for analysis of the base HPMC powders regardless of the substitution type or viscosity grade and that the obtained results were not frequency dependent. The results of dielectric measurements of solid dispersions prepared by hot melt extrusion were compared with predicted values of the Gordon-Taylor equation. It was found that time-temperature superposition effects and small molecule frequency dependence makes broadly applying determination of the glass transition temperature in drug dispersions by dielectric spectroscopy prohibitively difficult.


Asunto(s)
Espectroscopía Dieléctrica/métodos , Portadores de Fármacos/química , Derivados de la Hipromelosa/química , Itraconazol/química , Rastreo Diferencial de Calorimetría , Química Farmacéutica/métodos , Itraconazol/administración & dosificación , Reproducibilidad de los Resultados , Factores de Tiempo , Temperatura de Transición , Viscosidad
12.
J Pharm Sci ; 102(12): 4330-6, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24114922

RESUMEN

Hot-melt granulation (HMG) by twin screw extrusion is a novel technology for the continuous processing of pharmaceuticals but confidence must still be gained regarding whether the environment affects drug properties. In this preliminary study, granulation was studied for a model product containing lactose monohydrate and active ingredients of differing water solubility, namely ibuprofen versus caffeine. The formulations were granulated at 220 rpm and 100°C with polyethylene glycol binders of differing molecular weights and at concentrations between 6.5% and 20%. In terms of granule properties, the low melting point of ibuprofen had a dominant influence by producing larger, stronger granules, whereas the caffeine products were more comparable to a blank containing no active ingredient. Drug degradation was study by differential scanning calorimetry, X-ray diffraction, and high-pressure liquid chromatography. The only detected change was the dehydration of lactose monohydrate for the caffeine and blank products, whereas the lubricating influence of the ibuprofen protected its granules. The short residence time (∼60 s) was consider to be influential in minimizing damage of the drug despite the high temperature and shear attributed to HMG inside a twin screw extruder.


Asunto(s)
Antiinflamatorios no Esteroideos/química , Cafeína/química , Composición de Medicamentos , Ibuprofeno/química , Composición de Medicamentos/instrumentación , Estabilidad de Medicamentos , Calor , Lactosa/química , Tamaño de la Partícula , Solubilidad , Difracción de Rayos X
13.
Drug Dev Ind Pharm ; 39(3): 413-24, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23216244

RESUMEN

Suspension-type metered dose inhaler formulations characteristically have a high degree of dispersion instability. This may occur as the result of any of a large number of formulation issues including phase separation, particle growth, agglomeration/flocculation, moisture ingress, and particle interactions with both the canister material and other particles. Many of these undesirable instabilities may arise as a result of the physical and chemical properties of the dispersed powder in the liquid propellant system. As such, this review provides a detailed understanding of the characteristics of the dispersed phase in the liquid propellant system necessary to ensure stability of the final formulation.


Asunto(s)
Sistemas de Liberación de Medicamentos , Estabilidad de Medicamentos , Inhaladores de Polvo Seco/instrumentación , Pulmón/efectos de los fármacos , Inhaladores de Dosis Medida , Polvos , Administración por Inhalación , Humanos , Tamaño de la Partícula
14.
Eur J Pharm Biopharm ; 77(2): 207-15, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21130874

RESUMEN

Substantial improvements in transplant therapy have been made in the past four decades resulting in the acceptance of organ transplantation as a viable treatment for late-stage disease and organ failure. More recently, lung transplantation has gained acceptance; however, high incidence of chronic rejection and opportunistic infections has limited success rates in comparison with other transplant procedures. To achieve more targeted therapy, pulmonary administration of nebulized tacrolimus (TAC) colloidal dispersion once daily for 28 consecutive days in Sprague Dawley (SD) rats has been investigated for safety and systemic elimination. A liquid dispersion of colloidal TAC and lactose (1:1 ratio by weight) was aerosolized using a vibrating mesh nebulizer and administered via a nose-only dosing chamber. Blood chemistry and histological comparisons to saline-dosed animals showed no clinically significant differences in liver and kidney function or lung tissue damage. Maximum blood and lung concentrations sampled 1h after the final dose showed TAC concentrations of 10.1 ± 1.4 ng/mL and 1758.7 ± 80.0 ng/g, respectively. Twenty-four hours after the final dose, systemic TAC concentrations measured 1.0 ± 0.5 ng/mL, which is well below clinically accepted trough concentrations (5-15 ng/mL) for maintenance therapy, and therefore, would not be expected to induce toxic side effects. The propensity for pulmonary retention seen when compared to single dose lung levels may be due to macrophage uptake and the lipophilic nature of TAC. Additionally, three month stability testing of TAC powder for reconstitution showed no changes in amorphous nature or drug potency when stored at ambient conditions. TAC colloidal dispersion proved to be non-toxic when administered by pulmonary inhalation to SD rats over 28 days while providing therapeutic concentrations locally. This delivery strategy may prove safe and effective for the prevention of lung allograft rejection in lung transplant recipients.


Asunto(s)
Rechazo de Injerto/prevención & control , Inmunosupresores/administración & dosificación , Trasplante de Pulmón , Pulmón/efectos de los fármacos , Tacrolimus/administración & dosificación , Tacrolimus/química , Administración por Inhalación , Animales , Recuento de Células Sanguíneas , Pruebas de Química Clínica , Coloides , Evaluación Preclínica de Medicamentos , Estabilidad de Medicamentos , Femenino , Inmunosupresores/química , Inmunosupresores/farmacocinética , Inmunosupresores/uso terapéutico , Lactosa , Masculino , Nebulizadores y Vaporizadores , Difracción de Polvo , Ratas , Solubilidad , Tacrolimus/farmacocinética , Tacrolimus/uso terapéutico , Trasplante Homólogo
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