Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 55
Filter
1.
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1559906

ABSTRACT

Introducción: Las fracturas del antebrazo comprometen la diáfisis del radio y el cúbito. Su relación anatómica desempeña un papel importante porque el antebrazo se vincula con los movimientos de la mano para garantizar la función de la extremidad y de los tejidos blandos. Objetivo: Evaluar los resultados del tratamiento de la fractura diafisiarias de antebrazo con placa de compresión dinámica. Métodos: Se realizó un estudio prospectivo, longitudinal y descriptivo en 28 pacientes con fractura diafisaria de antebrazo, intervenidos quirúrgicamente con placa de compresión dinámica en el Hospital Ortopédico Docente "Fructuoso Rodríguez". Los resultados fueron evaluados según la escala funcional de Grace-Eversmann. Resultados: La edad media fue de 38 años, con una proporción entre sexos de 2,1:1. Predominaron las fracturas del tercio medio del radio y del cúbito. Se afectó más el lado izquierdo, pero en el 75 % de los casos hubo un excelente resultado. No se registraron fallas con la técnica quirúrgica aplicada. Conclusiones: La osteosíntesis con placa de compresión dinámica en las fracturas diafisarias de antebrazo es una alternativa adecuada para garantizar tasas de consolidación elevadas y resultados funcionales excelentes.


Introduction: Fractures of the forearm compromise the diaphysis of the radius and ulna. Their anatomical relationship plays an important role because the forearm is linked to hand movements to ensure limb and soft tissue function. Objective: To evaluate the results of treating diaphyseal forearm fracture with dynamic compression plate. Methods: A prospective, longitudinal and descriptive study was carried out in 28 patients with diaphyseal fracture of the forearm. They underwent surgery with a dynamic compression plate at Fructuoso Rodríguez Teaching Orthopedic Hospital. The results were evaluated according to Grace-Eversmann functional scale. Results: The mean age was 38 years, with a gender ratio of 2.1:1. Fractures of the middle third of the radius and ulna predominated. The left side was affected more, but 75% of the cases had excellent result. No failures were recorded with the applied surgical technique. Conclusions: Osteosynthesis with dynamic compression plating in diaphyseal fractures of the forearm is a suitable alternative to guarantee high consolidation rates and excellent functional results.

2.
Chem Res Toxicol ; 36(1): 43-52, 2023 01 16.
Article in English | MEDLINE | ID: mdl-36598842

ABSTRACT

Little filtered cigars are tobacco products with many cigarette-like characteristics. However, despite cigars falling under the U.S. Food and Drug Administration regulatory authority, characterizing flavors, which are still allowed in little filtered cigars, and filter design may influence how people use the products and the resulting exposure to harmful and potentially harmful constituents. We estimated nicotine mouth level intake (MLI) from analyses of little cigar filter butt solanesol levels, brand characteristics, carbon monoxide boost, and puff volume in 48 dual cigarette/cigar users during two repeat bouts of ad lib smoking of three little filtered cigar brands. Mean nicotine MLI for the three brands was significantly different with Swisher Sweets (0.1% ventilation) Cherry at 1.20 mg nicotine, Cheyenne Menthol (1.5%) at 0.63 mg, and Santa Fe unflavored (49%) at 0.94 mg. The association between nicotine MLI and puff volume was the same between Cheyenne Menthol and Santa Fe unflavored. However, these were different from Swisher Sweets Cherry. At least five main factors─flavor, ventilation, filter design, nicotine delivery related to tar, and user puff volume─may directly or indirectly impact MLI and its association with other measures. We found that users of little filtered cigars that have different filter ventilation and flavor draw dissimilar amounts of nicotine from the product, which may be accompanied by differences in exposure to other harmful smoke constituents.


Subject(s)
Nicotine , Tobacco Products , Adult , Humans , Nicotine/analysis , Menthol , Tobacco Products/analysis , Smoking , Nicotiana , Mouth/chemistry
3.
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1559895

ABSTRACT

Introducción: La fractura del extremo distal del húmero constituye un verdadero reto para los traumatólogos. Se han diseñado numerosos métodos de tratamiento quirúrgico para restaurar anatómicamente la superficie articular y lograr una estabilidad que permita la movilidad y la pronta incorporación del paciente a sus actividades diarias. Objetivo: Evaluar los resultados del tratamiento quirúrgico de la fractura del húmero distal con placas perpendiculares Métodos: Se realizó un estudio prospectivo, longitudinal, descriptivo en 18 pacientes con fractura del húmero distal, intervenidos quirúrgicamente con el sistema de placas perpendiculares en el Hospital Ortopédico Docente "Fructuoso Rodríguez" en el período 2017-2020. Los resultados se evaluaron según la escala de la clínica Mayo para la función del codo. Resultados: Se estudiaron 18 casos con un promedio de edad de 49 años. El tipo de fractura más frecuente fue la simple articular. Al año la flexoextensión media fue de 1120/160 y la pronosupinación de 810/800. La complicación más común fue la rigidez articular. El 50 % de los resultados fueron excelentes. Conclusiones: El tratamiento de la fractura de húmero distal con placas perpendiculares ofreció buenos resultados clínicos y funcionales por lo que constituye una opción válida en el Hospital Ortopédico Docente "Fructuoso Rodríguez".


Introduction: The fracture of the distal end of the humerus is a real challenge for traumatologists. Numerous surgical treatment methods have been designed to anatomically restore the joint surface and achieve stability that allows mobility and prompt return of the patient to daily activities. Objective: To evaluate the results of the surgical treatment of the distal humerus fracture with perpendicular plates. Methods: A prospective, longitudinal, descriptive study was carried out in 18 patients with fractures of the distal humerus, who underwent surgery with the perpendicular plate system. The results were evaluated according to Mayo Clinic scale for elbow function. Results: Eighteen cases with an average age of 49 years were studied. The most frequent type of fracture was simple joint. At one year, mean flexoextension was 1120/160 and pronosupination 810/800. The most common complication was joint stiffness. 50% of the results were excellent. Conclusions: The treatment of the distal humerus fracture with perpendicular plates offered good clinical and functional results, in consequence it constitutes a valid option at Fructuoso Rodríguez Orthopedic Teaching Hospital.

4.
Eur J Pharm Biopharm ; 165: 22-30, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33971274

ABSTRACT

Drug delivery to the colon offers great promise for local treatment of colonic diseases as it allows bypassing systemic absorption in the small intestine, thereby increasing luminal drug concentrations in the colon. The primary objective of this in vivo pharmaco-scintigraphy study was to assess the colon drug targeting accuracy of a metronidazole benzoate colonic drug delivery system intended for local treatment of Clostridioides difficile infections. Additionally, it was assessed if the concept of mucoadhesion would increase colonic residence time and promote higher drug bioavailability. Two different capsule formulations were designed and tested in healthy human subjects. Capsules contained either non-mucoadhesive (NM) or mucoadhesive (M) microgranules, both loaded with 100 mg metronidazole benzoate (antibiotic prodrug) and 5 mg samarium oxide (scintigraphy tracer). Filled capsules were coated with a colonic-targeting technology consisting of two functional layers, which allow for accelerated drug release mediated by the intestinal pH in combination with colonic bacteria. Coated capsules were neutron-activated to yield the radioisotope 153Sm prior to administration to 18 healthy subjects. Gamma-scintigraphy imaging was combined with the measurement of drug plasma levels. Formulation NM showed high colon-targeting accuracy. Initial capsule disintegration within the targeted ileocolonic region was observed in 8 out of 9 subjects (89%) with colonic arrival times in the range of 3.5-12 h and reduced systemic exposure. In contrast, the mucoadhesive formulation M showed some inconsistency regarding the site of initial capsule disintegration (targeting accuracy 56%). Variability of drug release was attributed to self-adhesion and agglomeration of the mucoadhesive microparticles within the capsule. Accurate ileocolonic delivery of metronidazole-loaded microgranules was achieved following oral administration of colonic-targeted capsules. Delayed drug release from NM microparticles in the colon leads to a reduced systemic exposure compared to immediate-release data from literature and presumably elevated drug concentrations in the colonic lumen. This approach offers promising options for the local treatment of colonic diseases.


Subject(s)
Colon/diagnostic imaging , Drug Carriers/chemistry , Intestinal Mucosa/diagnostic imaging , Metronidazole/administration & dosage , Administration, Oral , Adult , Biological Availability , Capsules , Cell-Derived Microparticles , Colon/metabolism , Colon/microbiology , Drug Liberation , Enterocolitis, Pseudomembranous/drug therapy , Female , Healthy Volunteers , Humans , Intestinal Mucosa/metabolism , Intestinal Mucosa/microbiology , Male , Metronidazole/pharmacokinetics , Middle Aged , Oxides/administration & dosage , Radioactive Tracers , Radionuclide Imaging , Samarium/administration & dosage , Young Adult
5.
Int J Pharm ; 583: 119379, 2020 Jun 15.
Article in English | MEDLINE | ID: mdl-32360546

ABSTRACT

Enteric-coated dosage forms are widely used for targeting the ileo-colonic region of the gastrointestinal (GI) tract. However, accurate targeting is challenging due to intra- and inter-individual variability in intestinal paramaters such as fluid pH and transit times, which occasionally lead to enteric coating failure. As such, a unique coating technology (Phloral™), which combines two independent release mechanisms - a pH trigger (Eudragit® S; dissolving at pH 7) and a microbiota-trigger (resistant starch), has been developed, offering a fail-safe approach to colonic targeting. Here, we demonstrate that the inclusion of resistant starch in the coating does not affect the pH mediated drug release mechanism or the robustness of the coating in the upper GI tract. In order to make the resistant starch more digestible by bacterial enzymes, heat treatment of the starch in the presence of butanol was required to allow disruption of the crystalline structure of the starch granules. Under challenging conditions of limited exposure to high pH in the distal small intestine fluid and rapid transit through the colon, often observed in patients with inflammatory bowel disease, particularly in ulcerative colitis, this dual-trigger pH-enzymatic coating offers a revolutionary approach for site specific drug delivery to the large intestine.


Subject(s)
Bacteria/enzymology , Colon/microbiology , Gastrointestinal Microbiome , Polymethacrylic Acids/chemistry , Resistant Starch/metabolism , Colon/metabolism , Drug Compounding , Humans , Hydrogen-Ion Concentration , Intestinal Absorption , Intestinal Secretions/chemistry , Tablets, Enteric-Coated
6.
Int J Pharm ; 583: 119372, 2020 Jun 15.
Article in English | MEDLINE | ID: mdl-32344022

ABSTRACT

Inflammatory bowel disease (IBD) is a debilitating condition, estimated to affect 7 million people worldwide. Current IBD treatment strategies are substandard, relying on colonic targeting using the pH gradient along the gastrointestinal tract. Here, we describe an innovative colonic targeting concept, OPTICORE™ coating technology. OPTICORE™ combines two release triggers (pH and enzyme: Phloral™) in the outer layer, with an inner layer promoting a release acceleration mechanism (Duocoat™). The technology comprises an inner layer of partially neutralized enteric polymer with a buffer agent and an outer layer of a mixture of Eudragit® S and resistant starch. 5-aminosalicylic acid (5-ASA) tablets were coated with different inner layers, where the type of polymer, buffer salt concentration and pH of neutralization, were investigated for drug release acceleration. Buffer capacity of polymethacrylate neutralized polymer significantly contributes to the buffer capacity of the inner layer formulation, while buffer salt concentration is a major contributor to dispersion buffer capacity in the case of hypromellose enteric polymer formulations. An interplay between buffer capacity, pH and ionic strength contributes to an accelerated drug release. Resistant starch does not impact the enteric properties but allows for drug release mediated by colonic bacterial enzymes, ensuring complete drug release. Therefore, OPTICORE™ technology is designed to offer significant advantages over standard enteric coatings, particularly allowing for more accurate colonic drug delivery in ulcerative colitis patients.


Subject(s)
Bacteria/enzymology , Colon/microbiology , Gastrointestinal Agents/chemistry , Mesalamine/chemistry , Polymethacrylic Acids/chemistry , Resistant Starch/metabolism , Buffers , Colon/metabolism , Drug Compounding , Drug Liberation , Feces/microbiology , Gastrointestinal Agents/metabolism , Humans , Hydrogen-Ion Concentration , Intestinal Absorption , Kinetics , Mesalamine/metabolism , Osmolar Concentration , Tablets, Enteric-Coated
7.
J Chromatogr A ; 1565: 124-129, 2018 Aug 31.
Article in English | MEDLINE | ID: mdl-29945789

ABSTRACT

Nitrobenzene, a potentially harmful compound found in tobacco smoke, has been largely excluded from prior analysis due to difficulties with quantification. Quantifying harmful compounds in cigarette smoke is useful to compare products, to examine the impact of design parameters on delivery, and to help estimate exposures. A sensitive high-throughput method has been developed for quantifying nitrobenzene in machine-generated mainstream cigarette smoke using isotope dilution gas chromatography-tandem mass spectrometry (ID-GC-MS/MS). This method has sufficient sensitivity to measure vapor phase nitrobenzene concentrations in the low nanogram range, with a 418 pg/cig method limit of detection. Precision estimates from two quality control cigarette products resulted in percent relative standard deviations of 11.5% and 14.9%; product variability estimates from 13 cigarette products resulted in percent relative standard deviations ranging from 2.8% to 16.9%. Nitrobenzene in the machine-generated, mainstream smoke from 15 cigarette products are reported and range from 18 to 38 ng/cig under the Health Canada Intense smoking regimen.


Subject(s)
Gas Chromatography-Mass Spectrometry/methods , Nicotiana/chemistry , Nitrobenzenes/analysis , Tobacco Smoke Pollution/analysis , Calibration , Canada , Ions , Limit of Detection , Particulate Matter/analysis , Reproducibility of Results , Tandem Mass Spectrometry , Tobacco Products/analysis
8.
Tob Regul Sci ; 3(1): 81-94, 2017 Dec 01.
Article in English | MEDLINE | ID: mdl-28220149

ABSTRACT

OBJECTIVE: Our objective was to characterize mainstream smoke constituent deliveries from SPECTRUM variable nicotine research cigarettes under 2 machine smoking regimens. SPECTRUM cigarettes are manufactured by the 22nd Century company for the National Institute on Drug Abuse, National Institutes of Health to contain varying (including reduced) levels of nicotine. METHODS: Mainstream smoke constituent deliveries of "tar," nicotine, carbon monoxide, tobacco-specific nitrosamines (N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)), benzo[a]pyrene, aromatic amines, and carbonyls were analyzed in 23 varieties of SPECTRUM cigarettes using ISO 17025 accredited methods. RESULTS: Data are presented as means and standard deviations of 5 replicates for all analytes. CONCLUSIONS: Under the ISO smoking regimen, mean levels of many smoke emissions for SPECTRUM varieties were comparable to the 3R4F research cigarette. Calculated SPECTRUM elasticity ranged from 1.6 to 4.0. Accordingly, under intense machine smoking conditions differences in emissions of SPECTRUM cigarettes were apparent. In addition, NNN increased with smoke nicotine while the same rate of change was not seen for NNK. It is important to monitor levels of chemicals of public health concern and regulatory interest as technologies emerge to reduce levels of nicotine or other targeted chemicals in tobacco products.

9.
Eur J Pharm Biopharm ; 105: 156-65, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27302556

ABSTRACT

Mucoadhesive microparticles formulated in a capsule and delivered to the gastrointestinal tract might be useful for local drug delivery. However, swelling and agglomeration of hydrophilic polymers in the gastrointestinal milieu can have a negative influence on particle retention of mucoadhesive microparticles. In this work, we investigated the impact of dry-coating with nano-sized hydrophilic fumed silica on dispersibility and particle retention of mucoadhesive microparticles. As a model for local treatment of gastrointestinal diseases, antibiotic therapy of Clostridium difficile infections with metronidazole was selected. For particle preparation, we used a two-step fluidized-bed method based on drug loading of porous microcarriers and subsequent outer coating with the mucoadhesive polymer chitosan. The prepared microparticles were analysed for drug content, and further characterized by thermal analysis, X-ray diffraction, and scanning electron microscopy. The optimal molecular weight and content of chitosan were selected by measuring particle retention on porcine colonic mucosa under dynamic flow conditions. Mucoadhesive microparticles coated with 5% (weight of chitosan coating/total weight of particles) of low molecular weight chitosan showed good in vitro particle retention, and were used for the investigation of dispersibility enhancement. By increasing the amount of silica, the dissolution rate measured in the USPIV apparatus was increased, which was an indirect indication for improved dispersibility due to increased surface area. Importantly, mucoadhesion was not impaired up to a silica concentration of 5% (w/w). In summary, mucoadhesive microparticles with sustained-release characteristics over several hours were manufactured at pilot scale, and dry-coating with silica nanoparticles has shown to improve the dispersibility, which is essential for better particle distribution along the intestinal mucosa in humans. Therefore, this advanced drug delivery concept bears great potential, in particular for local treatment of gastrointestinal diseases.


Subject(s)
Gastrointestinal Diseases/drug therapy , Drug Delivery Systems , Humans , Microscopy, Electron, Scanning , Particle Size , Powder Diffraction
10.
Eur J Pharm Sci ; 90: 64-75, 2016 Jul 30.
Article in English | MEDLINE | ID: mdl-27132811

ABSTRACT

Water is known to exhibit pronounced effects on lipid-based formulations (LBFs) and much research has focused on aqueous dispersion and dilution behavior regarding biopharmaceutical performance. From a product quality perspective, it is also critical to study a range of lower water amounts in formulations with respect to capsule filling. The present work addressed the need for a better understanding of LBF microstructure by taking percolation theory into account. The effects of increasing amounts of water on LBFs were analyzed by conductivity, water activity, time-domain nuclear magnetic resonance, and diffusing wave spectroscopy. Results were interpreted using percolation theory and preliminary mechanical tests were conducted on gelatin and hypromellose (HPMC) capsule shells. For both LBF systems, increasing water amounts led to marked changes in the microstructure of the formulations. Percolation laws could be fitted adequately to the data and thresholds were identified for the formation of continuous water channels (ϕwc~0.02-0.06). A new theoretical model was proposed for water activity. The preliminary shell material studies showed that the threshold for generating water channels in the formulation could be correlated to mechanical changes of the capsule shell that were relatively more pronounced in the case of gelatin. This mechanistic study demonstrated the importance of understanding and monitoring of microstructural changes occurring in LBFs with increasing amounts of water, which will help to design quality into the final dosage form.


Subject(s)
Capsules/chemistry , Drug Compounding/methods , Lipids/chemistry , Models, Chemical , Water/chemistry , Drug Industry/methods , Electric Conductivity
11.
Chem Res Toxicol ; 29(6): 1051-63, 2016 06 20.
Article in English | MEDLINE | ID: mdl-27222918

ABSTRACT

The aim of this study is to explore how differences in cigarette physical design parameters influence tar, nicotine, and carbon monoxide (TNCO) yields in mainstream smoke (MSS) using the International Organization of Standardization (ISO) smoking regimen. Standardized smoking methods were used to evaluate 50 U.S. domestic brand cigarettes and a reference cigarette representing a range of TNCO yields in MSS collected from linear smoking machines using a nonintense smoking regimen. Multivariate statistical methods were used to form clusters of cigarettes based on their ISO TNCO yields and then to explore the relationship between the ISO generated TNCO yields and the nine cigarette physical design parameters between and within each cluster simultaneously. The ISO generated TNCO yields in MSS are 1.1-17.0 mg tar/cigarette, 0.1-2.2 mg nicotine/cigarette, and 1.6-17.3 mg CO/cigarette. Cluster analysis divided the 51 cigarettes into five discrete clusters based on their ISO TNCO yields. No one physical parameter dominated across all clusters. Predicting ISO machine generated TNCO yields based on these nine physical design parameters is complex due to the correlation among and between the nine physical design parameters and TNCO yields. From these analyses, it is estimated that approximately 20% of the variability in the ISO generated TNCO yields comes from other parameters (e.g., filter material, filter type, inclusion of expanded or reconstituted tobacco, and tobacco blend composition, along with differences in tobacco leaf origin and stalk positions and added ingredients). A future article will examine the influence of these physical design parameters on TNCO yields under a Canadian Intense (CI) smoking regimen. Together, these papers will provide a more robust picture of the design features that contribute to TNCO exposure across the range of real world smoking patterns.


Subject(s)
Models, Statistical , Smoke/analysis , Tobacco Products/analysis , Carbon Monoxide/analysis , Carbon Monoxide/standards , International Cooperation , Multivariate Analysis , Nicotine/analysis , Nicotine/standards , Reference Standards , Tars/analysis , Tars/standards , Tobacco Products/standards
12.
Transl Res ; 176: 38-68, 2016 10.
Article in English | MEDLINE | ID: mdl-27220087

ABSTRACT

Ulcerative colitis and Crohn's disease are the 2 major phenotypes of inflammatory bowel disease (IBD), which are influenced by a complex interplay of immunological and genetic elements, though the precise etiology still remains unknown. With IBD developing into a globally prevailing disease, there is a need to explore new targets and a thorough understanding of the pathophysiological differences between the healthy and diseased gut could unearth new therapeutic opportunities. In this review, we provide an overview of the major aspects of IBD pathogenesis and thereafter present a comprehensive analysis of the gut pathophysiology leading to a discussion on some of the most promising targets and biologic therapies currently being explored. These include various gut proteins (CXCL-10, GATA-3, NKG2D, CD98, microRNAs), immune cells recruited to the gut (mast cells, eosinophils, toll-like receptors 2, 4), dysregulated proinflammatory cytokines (interleukin-6, -13, -18, -21), and commensal microbiota (probiotics and fecal microbiota transplantation). We also evaluate some of the emerging nonconventional therapies being explored in IBD treatment focusing on the latest developments in stem cell research, oral targeting of the gut-associated lymphoid tissue, novel anti-inflammatory signaling pathway targeting, adenosine deaminase inhibition, and the beneficial effects of antioxidant and nutraceutical therapies. In addition, we highlight the growth of biologics and their targets in IBD by providing information on the preclinical and clinical development of over 60 biopharmaceuticals representing the state of the art in ulcerative colitis and Crohn's disease drug development.


Subject(s)
Gastrointestinal Tract/physiopathology , Inflammatory Bowel Diseases/physiopathology , Inflammatory Bowel Diseases/therapy , Molecular Targeted Therapy , Animals , Biological Products/pharmacology , Biological Products/therapeutic use , Gastrointestinal Tract/drug effects , Gastrointestinal Tract/microbiology , Gastrointestinal Tract/pathology , Humans , Inflammatory Bowel Diseases/drug therapy , Inflammatory Bowel Diseases/genetics , Microbiota/drug effects , Signal Transduction/drug effects
13.
Int J Pharm ; 502(1-2): 181-7, 2016 Apr 11.
Article in English | MEDLINE | ID: mdl-26892815

ABSTRACT

Monoclonal antibodies (mAbs) are highly effective therapeutic agents, administered exclusively by the parenteral route owing to their previously-documented instability in the gastrointestinal (GI) tract when delivered orally. To investigate the extent of the validity of this assumption, the stability of the tumor necrosis factor alpha (TNF-α) neutralizing IgG1 mAbs, infliximab and adalimumab, was studied in human GI conditions. In gastric fluid, infliximab and adalimumab degraded rapidly, with complete degradation occurring within 1 min. In small intestinal fluid, the molecules were shown to be more stable, but nonetheless degraded within a short time frame of 30 min. Investigations into the mechanisms responsible for infliximab and adalimumab instability in the small intestine revealed that the proteolytic enzyme elastase, and to a lesser extent the enzymes trypsin and chymotrypsin, was responsible for their degradation. By contrast, in the human colon, 75% and 50% of the dose of infliximab and adalimumab, respectively, were intact after 60 min, with conversion of mAbs into F(ab')2 Fab and Fc fragments detected in colonic conditions. These data indicate that therapeutic IgG1 antibodies are more stable in the colon than in the upper GI tract, therefore highlighting the potential for oral delivery of anti-TNF-α mAbs targeted to the colon.


Subject(s)
Adalimumab/chemistry , Infliximab/chemistry , Antirheumatic Agents/chemistry , Chymotrypsin/chemistry , Colon/metabolism , Feces/chemistry , Gastric Juice/chemistry , Humans , Immunoglobulin G/immunology , Intestinal Secretions/chemistry , Pancreatic Elastase/chemistry , Pancreatin/chemistry , Trypsin/chemistry , Tumor Necrosis Factor-alpha/immunology
14.
Tob Regul Sci ; 2(2): 94-105, 2016.
Article in English | MEDLINE | ID: mdl-26779559

ABSTRACT

OBJECTIVE: To provide researchers an extensive characterization of the SPECTRUM variable nicotine research cigarettes. METHODS: Data on cigarette physical properties, nicotine content, harmful and potentially harmful constituents in the tobacco filler was compiled. RESULTS: Data on physical properties, concentrations of menthol, nicotine and minor alkaloids, tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons, ammonia, and toxic metals in the filler tobacco for all available varieties of Spectrum research cigarettes are provided. The similarity in the chemistry and physical properties of SPECTRUM cigarettes to commercial cigarettes renders them acceptable for use in behavioral studies. Baseline information on harmful and potentially harmful constituents in research tobacco products, particularly constituent levels such as minor alkaloids that fall outside typical ranges reported for commercial, provide researchers with the opportunity to monitor smoking behavior and to identify biomarkers that will inform efforts to understand the role of nicotine in creating and sustaining addiction. CONCLUSIONS: Well characterized research cigarettes suitable for human consumption are an important tool in clinical studies for investigating the physiological impacts of cigarettes delivering various levels of nicotine, the impact of reduced nicotine cigarettes on nicotine addiction, and the relationship between nicotine dose and smoking behavior.

15.
J Pharm Sci ; 104(10): 3351-65, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26108711

ABSTRACT

The development of novel systems with oral protein delivery as ultimate goal represents an important field of pharmaceutics. Prilling of protein-loaded polymeric solutions into lipid-based hardening baths could provide here an attractive formulating technology. As the obtained microgel dispersion can be directly capsule-filled, no drying step is required and thermal drug degradation is avoided. This study aims to find excipient combinations for the novel prilling process and investigate systematically diverse material and process factors. Bovine serum albumin and mono-N-carboxymethyl chitosan were selected as model protein and prilling polymer, respectively. The prilling suitability of 880 formulations was screened with 60 ternary phase diagrams comprising two co-solvents, 10 different glycerides, and three so-called complementary excipients. Preliminary capsule compatibility was tested for one month on 245 formulations in hard and soft capsules with different shell materials. Ternary phase diagrams' center points were used to evaluate morphology, encapsulation efficiency, and protein stability of the prilled microgels. As result, several formulations proved suitable for prilling and compatible for capsule filling. Statistical analysis using partial least square regression revealed significant factors regarding different quality attributes of microgel dispersions. Therefore, an improved understanding was obtained for this promising drug delivery approach.


Subject(s)
Drug Delivery Systems/methods , Lipids/chemistry , Proteins/administration & dosage , Administration, Oral , Chemistry, Pharmaceutical , Drug Industry , Drug Stability , Excipients , Gels , Serum Albumin, Bovine/chemistry
16.
Int J Pharm ; 487(1-2): 157-66, 2015 Jun 20.
Article in English | MEDLINE | ID: mdl-25882011

ABSTRACT

The objective of the present work was to develop an improved method to quantify particle retention on mucosal tissue under dynamic flow conditions with simultaneous determination of drug dissolution. The principle was to dissolve the collected inert carrier material and quantify specific marker ions by reliable analytical methods. The mucoadhesive model particles consisted of drug-loaded porous calcium carbonate microcarriers coated with chitosan, and quantification of calcium ions by capillary electrophoresis enabled to determine particle-retention kinetics on colonic mucosal tissue. The method was validated by image analysis, and the particle-retention assay was successfully applied to granulate material (125-250 mm) and small particles (<90 µm) with mucoadhesive properties. Particle retention on colonic mucosa was improved by increasing the chitosan content, demonstrating the sensitivity and usefulness of marker-ion analysis for quantification of detached particles. Furthermore, we showed that drug dissolution from mucoadhesive microparticles followed comparable kinetics in the particle-retention assay and the standard USP IV method. Our findings are helpful for the development of micro-sized colonic drug delivery systems, in particular for optimization of mucoadhesive properties and sustained drug release kinetics of porous drug carriers.


Subject(s)
Intestinal Mucosa , Nanoparticles , Tissue Adhesives , Animals , Calcium Carbonate/chemistry , Chemistry, Pharmaceutical , Colon/metabolism , Drug Delivery Systems , In Vitro Techniques , Ions , Particle Size , Solubility , Swine
17.
Pediátr. Panamá ; 44(1): 33-36, Abril-Mayo 2015.
Article in Spanish | LILACS | ID: biblio-848706

ABSTRACT

Introducción: El síndrome de Marshall o PFAPA, por sus siglas en inglés (Periodic fever, aphtas, pharyngitis and cervical adenopathies), es una patología que se caracteriza principalmente por cuadros de ebres periódicas asociadas a faringitis y estomatitis. Los pacientes suelen recibir múltiples cursos de antibióticos antes de ser diagnosticados. Se desconoce su causa exacta, el diagnóstico es clínico y se con rma con la mejoría del cuadro luego de la administración de prednisona oral. Caso clínico: Se presenta el caso de una paciente de 4 años de edad quien inició con episodios febriles recurrentes desde los 9 meses de edad y luego de múltiples ciclos de antibióticos se sospecha el Síndrome de Marshall el cual mejoró luego del abordaje terapeútico dirigido. Discusión: El síndrome de Marshall o PFAPA es una entidad que debe ser considerada durante la atención primaria en aquellos pacientes que acuden frecuentemente por cuadros de ebre, faringitis y estomatitis aftosas. La sospecha de este diagnóstico mejora la calidad de vida del paciente y sus familiares considerando la ansiedad que produce a los padres llevar a su niño con frecuencia al cuarto de urgencias.


Introduction: Marshall syndrome or PFAPA (Periodic fever, aphtas, pharyngitis and cervical adenopathies), is a condition that is mainly characterized by periodic fevers associated with pharyngitis and stomatitis. Patients usually receive multiple courses of antibiotics before being diagnosed. The exact cause is unknown, the diagnosis is clinical and con rmed with the improvement of the condition after administration of oral prednisone. Case report: We report a case of a 4 year old girls who started with recurrent febrile episodes from 9 months and after multiple courses of antibiotics, Marshall Syndrome was suspected and patient improved after targeted therapy. Discussion: Marshall Syndrome or PFAPA is a condition that must be considered during primary care attention of those patients who frequently consult by cyclic episodes of fever, pharyngitis and aphthous stomatitis. The suspicion of this diagnosis improves the quality of life of patients and their families considering the anxiety of parents who needs to take their child to the emergency

18.
J Pharm Sci ; 103(11): 3675-3687, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25241928

ABSTRACT

Oral delivery of biologicals is a thriving field in pharmaceutics and the first challenge is to achieve a stable drug product. Interesting is prilling of a drug-containing polymeric solution as microgel into an aqueous hardening bath where crosslinking occurs. However, to deliver a final dosage form, for example, soft gelatin capsules, the aqueous hardening bath must be removed, thus leading to manufacturing processes that are potentially harmful for the active. The current work introduces a prilling method with a lipid-based hardening bath, which could theoretically be filled directly into capsules. Bovine serum albumin (BSA) and mono-N-carboxymethyl chitosan (MCC) were selected as model biological and encapsulating polymer, respectively. Several nonaqueous formulations of the receiving bath were investigated; calcium chloride was added to these formulations to allow the MCC gelling. The obtained microgels had average diameters of ∼300 µm and spherical to toroidal shapes, according to the hardening bath composition. Along with a high encapsulation efficiency (>85%), the microgels protected the BSA from any denaturing effect of the hardening bath. The release study showed a rather fast BSA release within the first 10 min from most microgels. This novel approach demonstrated technical viability for encapsulation of biologicals using lipid formulations regarding oral delivery.


Subject(s)
Biological Products/chemistry , Chitosan/chemistry , Drug Carriers , Lipids/chemistry , Serum Albumin, Bovine/chemistry , Administration, Oral , Biological Products/administration & dosage , Capsules , Chemistry, Pharmaceutical , Circular Dichroism , Drug Stability , Electrophoresis, Polyacrylamide Gel , Gels , Hardness , Hydrophobic and Hydrophilic Interactions , Kinetics , Protein Denaturation , Protein Stability , Serum Albumin, Bovine/administration & dosage , Solubility , Spectrometry, Fluorescence , Technology, Pharmaceutical/methods
19.
Eur J Pharm Biopharm ; 87(3): 548-58, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24568926

ABSTRACT

Drug loading into porous carriers may improve drug release of poorly water-soluble drugs. However, the widely used impregnation method based on adsorption lacks reproducibility and efficiency for certain compounds. The aim of this study was to evaluate a drug-loading method based on solvent evaporation and crystallization, and to investigate the underlying drug-loading mechanisms. Functionalized calcium carbonate (FCC) microparticles and four drugs with different solubility and permeability properties were selected as model substances to investigate drug loading. Ibuprofen, nifedipine, losartan potassium, and metronidazole benzoate were dissolved in acetone or methanol. After dispersion of FCC, the solvent was removed under reduced pressure. For each model drug, a series of drug loads were produced ranging from 25% to 50% (w/w) in steps of 5% (w/w). Loading efficiency was qualitatively analyzed by scanning electron microscopy (SEM) using the presence of agglomerates and drug crystals as indicators of poor loading efficiency. The particles were further characterized by mercury porosimetry, specific surface area measurements, differential scanning calorimetry, and USP2 dissolution. Drug concentration was determined by HPLC. FCC-drug mixtures containing equivalent drug fractions but without specific loading strategy served as reference samples. SEM analysis revealed high efficiency of pore filling up to a drug load of 40% (w/w). Above this, agglomerates and separate crystals were significantly increased, indicating that the maximum capacity of drug loading was reached. Intraparticle porosity and specific surface area were decreased after drug loading because of pore filling and crystallization on the pore surface. HPLC quantification of drugs taken up by FCC showed only minor drug loss. Dissolution rate of FCC loaded with metronidazole benzoate and nifedipine was faster than the corresponding FCC-drug mixtures, mainly due to surface enlargement, because only small fractions of amorphous drug (12.5%, w/w, and 8.9%, w/w, respectively) were found by thermal analysis. Combination of qualitative SEM analysis and HPLC quantification was sufficient to proof the feasibility of the solvent-evaporation method for the loading of various drugs into FCC. Mechanistic investigation revealed that a high specific surface area of the carrier is required to facilitate heterogeneous nucleation, and large pore sizes (up to 1 µm) are beneficial to reduce crystallization pressures and allow drug deposition within the pores. The solvent-evaporation method allows precise drug loading and appears to be suitable for scale-up.


Subject(s)
Calcium Carbonate/chemistry , Drug Carriers/chemistry , Pharmaceutical Preparations/chemistry , Solvents/chemistry , Adsorption , Chromatography, High Pressure Liquid/methods , Crystallization , Microscopy, Electron, Scanning/methods , Permeability , Porosity , Reproducibility of Results , Solubility , Surface Properties , Water/chemistry
20.
J Med Chem ; 57(1): 110-30, 2014 Jan 09.
Article in English | MEDLINE | ID: mdl-24367923

ABSTRACT

In preceding communications we summarized our medicinal chemistry efforts leading to the identification of potent, selective, and orally active S1P1 agonists such as the thiophene derivative 1. As a continuation of these efforts, we replaced the thiophene in 1 by a 2-, 3-, or 4-pyridine and obtained less lipophilic, potent, and selective S1P1 agonists (e.g., 2) efficiently reducing blood lymphocyte count in the rat. Structural features influencing the compounds' receptor affinity profile and pharmacokinetics are discussed. In addition, the ability to penetrate brain tissue has been studied for several compounds. As a typical example for these pyridine based S1P1 agonists, compound 53 showed EC50 values of 0.6 and 352 nM for the S1P1 and S1P3 receptor, respectively, displayed favorable PK properties, and penetrated well into brain tissue. In the rat, compound 53 maximally reduced the blood lymphocyte count for at least 24 h after oral dosing of 3 mg/kg.


Subject(s)
Pyridines/chemical synthesis , Receptors, Lysosphingolipid/agonists , Thiophenes/chemical synthesis , Animals , Brain/metabolism , Male , Pyridines/pharmacokinetics , Pyridines/pharmacology , Rats , Rats, Wistar , Structure-Activity Relationship , Thiophenes/pharmacokinetics , Thiophenes/pharmacology
SELECTION OF CITATIONS
SEARCH DETAIL
...