Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 73
Filtrar
1.
Drug Deliv Transl Res ; 6(6): 660-675, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27613190

RESUMEN

In vivo toxicity and absorption studies of topical ocular drugs are problematic, because these studies involve invasive tissue sampling and toxic effects in animal models. Therefore, different human corneal models ranging from simple monolayer cultures to three-dimensional models have been developed for toxicological prediction with in vitro models. Each system has its own set of advantages and disadvantages. Use of non-corneal cells, inadequate characterization of gene-expression profiles, and accumulation of genomic aberrations in human corneal models are typical drawbacks that decrease their reliability and predictive power. In the future, further improvements are needed for verifying comparable expression profiles and cellular properties of human corneal models with their in vivo counterparts. A rapidly expanding stem cell technology combined with tissue engineering may give future opportunities to develop new tools in drug toxicity studies. One approach may be the production of artificial miniature corneas. In addition, there is also a need to use large-scale profiling approaches such as genomics, transcriptomics, proteomics, and metabolomics for understanding of the ocular toxicity.


Asunto(s)
Córnea/efectos de los fármacos , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Pruebas de Toxicidad/métodos , Técnicas de Cultivo de Célula , Células Epiteliales/efectos de los fármacos , Humanos
2.
Eur J Pharm Biopharm ; 100: 1-8, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26686646

RESUMEN

Porous silicon (PSi) is a promising material for the delivery and sustained release of therapeutic molecules in various tissues. Due to the constant rinsing of cornea by tear solution as well as the short half-life of intravitreal drugs, the eye is an attractive target for controlled drug delivery systems, such as PSi microparticles. Inherent barriers ensure that PSi particles are retained in the eye, releasing drugs at the desired speed until they slowly break down into harmless silicic acid. Here, we have examined the in vitro cytotoxicity of positively and negatively charged thermally oxidized (TOPSi) and thermally carbonized (TCPSi) porous silicon microparticles on human corneal epithelial (HCE) and retinal pigment epithelial (ARPE-19) cells. In addition to ocular assessment under an inverted microscope, cellular viability was evaluated using the CellTiter Blue™, CellTiter Fluor™, and lactate dehydrogenase (LDH) assays. CellTiter Fluor proved to be a suitable assay but due to non-specific and interfering responses, neither CellTiter Blue nor LDH assays should be used when evaluating PSi particles. Our results suggest that the toxicity of PSi particles is concentration-dependent, but at least at concentrations less than 200µg/ml, both positively and negatively charged PSi particles are well tolerated by human corneal and retinal epithelial cells and therefore applicable for delivering drug molecules into ocular tissues.


Asunto(s)
Córnea/efectos de los fármacos , Sistemas de Liberación de Medicamentos/métodos , Epitelio Pigmentado de la Retina/efectos de los fármacos , Silicio/administración & dosificación , Silicio/toxicidad , Administración Oftálmica , Línea Celular , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Córnea/fisiología , Relación Dosis-Respuesta a Droga , Portadores de Fármacos/administración & dosificación , Portadores de Fármacos/toxicidad , Humanos , Porosidad , Epitelio Pigmentado de la Retina/fisiología
3.
Pharmacol Rev ; 67(3): 541-61, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26023145

RESUMEN

Peptides have long been recognized as a promising group of therapeutic substances to treat various diseases. Delivery systems for peptides have been under development since the discovery of insulin for the treatment of diabetes. The challenge of using peptides as drugs arises from their poor bioavailability resulting from the low permeability of biological membranes and their instability. Currently, subcutaneous injection is clinically the most common administration route for peptides. This route is cost-effective and suitable for self-administration, and the development of appropriate dosing equipment has made performing the repeated injections relatively easy; however, only few clinical subcutaneous peptide delivery systems provide sustained peptide release. As a result, frequent injections are needed, which may cause discomfort and additional risks resulting from a poor administration technique. Controlled peptide delivery systems, able to provide required therapeutic plasma concentrations over an extended period, are needed to increase peptide safety and patient compliancy. In this review, we summarize the current peptidergic drugs, future developments, and parenteral peptide delivery systems. Special emphasis is given to porous silicon, a novel material in peptide delivery. Biodegradable and biocompatible porous silicon possesses some unique properties, such as the ability to carry exceptional high peptide payloads and to modify peptide release extensively. We have successfully developed porous silicon as a carrier material for improved parenteral peptide delivery. Nanotechnology, with its different delivery systems, will enable better use of peptides in several therapeutic applications in the near future.


Asunto(s)
Sistemas de Liberación de Medicamentos , Diseño de Fármacos , Péptidos/administración & dosificación , Animales , Disponibilidad Biológica , Preparaciones de Acción Retardada , Portadores de Fármacos/química , Humanos , Nanotecnología/métodos , Péptidos/farmacocinética , Permeabilidad , Silicio/química
4.
Biomaterials ; 52: 44-55, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25818412

RESUMEN

Mesoporous materials are promising candidates for improving dissolution rate of poorly water-soluble drugs in vitro and their bioavailability in vivo. In the present study, sixteen batches of celecoxib-loaded PSi particles with pore sizes ranging from 17 to 58 nm and celecoxib content from 5 to 36 w-% were prepared and a detailed physicochemical characterization of the drug was performed by several methods. Interaction between co-culture of Caco-2/HT29-MTX cells and unloaded PSi particles was tested in toxicity assays, and increased toxicity for particles with large pore size was observed. Dissolution rate of celecoxib was improved in vitro by lowering the drug loading degree which hindered the recrystallization of celecoxib on the external surface of the particles. The fastest permeation of loaded celecoxib through the co-culture monolayer as well as the highest bioavailability in rats was observed with the particles with small pore size and low loading degree. New insights were obtained on how various parameters of the mesoporous delivery system affect the state of the drug inside the pores and its release in vitro and in vivo.


Asunto(s)
Celecoxib/administración & dosificación , Celecoxib/farmacocinética , Inhibidores de la Ciclooxigenasa 2/administración & dosificación , Inhibidores de la Ciclooxigenasa 2/farmacocinética , Portadores de Fármacos/química , Silicio/química , Administración Oral , Animales , Disponibilidad Biológica , Células CACO-2 , Técnicas de Cocultivo , Humanos , Masculino , Tamaño de la Partícula , Porosidad , Ratas Sprague-Dawley , Solubilidad
5.
Int J Pharm ; 485(1-2): 77-86, 2015 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-25746735

RESUMEN

Nanocrystallization is among the foremost drug delivery platform approaches for the commercial development of poorly soluble drugs. There exists an urge to enable a universal shift of the production of the solid nanocrystal formulations from laboratory scale to industrially feasible scale. The success of any formulation development depends on its transferability to large scale manufacture. The objectives of the study were to increase the nanocrystallization batch size and to screen and optimize parameters for industrially feasible itraconazole (ITC) and indomethacin (IND) nanocrystal composition for tablet formulation. Thus, ITC and IND were transformed into nanocrystal suspensions, using an increased batch size of a wet milling process, freeze-dried, and further developed into both direct compression (DC) and granulated (G) tableting masses. According to the investigated powder and tablet properties (true density, flowability, dose uniformity, maximum upper punch force, crushing strength, dissolution and disintegration) and stability testings, it was clear that the amount of the nanocrystals in the solid tablet formulation is critical in order to fully utilize the benefits of the nanocrystals, i.e., fast dissolution, and to produce high-quality tablets. The DC designs of both the model drugs with compositions including 40% of freeze-dried nanocrystalline drug powder outperformed the corresponding granulated tablets in all parameters after the stability surveillance.


Asunto(s)
Indometacina/química , Itraconazol/química , Nanopartículas , Nanotecnología , Tecnología Farmacéutica/métodos , Química Farmacéutica , Cristalización , Excipientes/química , Liofilización , Cinética , Polvos , Reología , Solubilidad , Comprimidos
6.
Eur J Pharm Sci ; 63: 96-102, 2014 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-24964293

RESUMEN

Intravenously administered nanocarriers are widely studied to improve the delivery of various therapeutic agents. However, recent in vivo studies have demonstrated that intravenously administered nanocarriers that do not contain any drug may affect cardiovascular function. Here we provide an example where the drug and the nanocarrier both affect the same cardiovascular parameters following intravenous administration. The peptide ghrelin antagonist (GhA) increases arterial pressure, while thermally hydrocarbonized porous silicon nanoparticles (THCPSi) transiently decrease it, as assessed with radiotelemetry in conscious rats. As a result, intravenous administration of GhA-loaded THCPSi nanoparticles partially antagonized GhA activity: arterial pressure was not increased. When the cardiovascular effects of GhA were blocked with atenolol pretreatment, GhA-loaded nanoparticles reduced arterial pressure to similar extent as drug-free nanoparticles. These data indicate that the biological activity of a drug delivered within a nanocarrier may be obscured by the biological responses induced by the nanocarrier itself.


Asunto(s)
Artefactos , Sistema Cardiovascular/efectos de los fármacos , Portadores de Fármacos/administración & dosificación , Portadores de Fármacos/farmacología , Nanopartículas/administración & dosificación , Péptidos/administración & dosificación , Péptidos/farmacología , Administración Intravenosa , Animales , Atenolol/farmacología , Presión Sanguínea/efectos de los fármacos , Portadores de Fármacos/química , Ghrelina/antagonistas & inhibidores , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos DBA , Nanopartículas/química , Ratas , Ratas Wistar , Silicio/administración & dosificación , Silicio/química , Silicio/farmacología
7.
J Pharm Biomed Anal ; 95: 229-37, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24699368

RESUMEN

This study assessed the validity of a multipoint near-infrared (NIR) spectroscopy method for in-line moisture content analysis during a freeze-drying process. It is known that the moisture content affects the stability of a freeze-dried product and hence it is a major critical quality attribute. Therefore assessment of the validity of an analytical method for moisture content determination is vital to ensure the quality of the final product. An aqueous sucrose solution was used as the model formulation of the study. The NIR spectra were calibrated to the moisture content using partial least squares (PLS) regression with coulometric Karl Fischer (KF) titration as the reference method. Different spectral preprocessing methods were compared for the PLS models. A calibration model transfer protocol was established to enable the use of the method in the multipoint mode. The accuracy profile was used as a decision tool to determine the validity of the method. The final PLS model, in which NIR spectra were preprocessed with standard normal variate transformation (SNV), resulted in low root mean square error of prediction value of 0.04%-m/v, i.e. evidence of sufficient overall accuracy of the model. The validation results revealed that the accuracy of the model was acceptable within the moisture content range 0.16-0.70%-m/v that is specific for the latter stages of the freeze-drying process. In addition, the results demonstrated the method's reliable in-process performance and robustness. Thus, the multipoint NIR spectroscopy method was proved capable of providing in-line evaluation of moisture content and it is readily available for use in laboratory scale freeze-drying research and development.


Asunto(s)
Espectroscopía Infrarroja Corta/métodos , Agua/análisis , Calibración , Liofilización , Análisis de los Mínimos Cuadrados
8.
Int J Pharm ; 467(1-2): 34-41, 2014 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-24680962

RESUMEN

Nanocrystal-based drug delivery systems provide important tools for ocular formulation development, especially when considering poorly soluble drugs. The objective of the study was to formulate ophthalmic, intraocular pressure (IOP) reducing, nanocrystal suspensions from a poorly soluble drug, brinzolamide (BRA), using a rapid wet milling technique, and to investigate their IOP reducing effect in vivo. Different stabilizers for the nanocrystals were screened (hydroxypropyl methylcellulose (HPMC), poloxamer F127 and F68, polysorbate 80) and HPMC was found to be the only successful stabilizer. In order to investigate both the effect of an added absorption enhancer (polysorbate 80) and the impact of the free drug in the nanocrystal suspension, formulations in phosphate buffered saline (PBS) at pH 7.4 and pH 4.5 were prepared. Particle size, polydispersity (PI), solid state (DSC), morphology (SEM) as well as dissolution behavior and the uniformity of the formulations were characterized. There was rapid dissolution of BRA (in PBS pH 7.4) from all the nanocrystal formulations; after 1 min 100% of the drug was fully dissolved. The effect was significantly pronounced at pH 4.5, where the dissolved fraction of drug was the highest. The cytotoxicity of nanocrystal formulations to human corneal epithelial cell (HCE-T) viability was tested. The effects of the nanocrystal formulations and the commercial product on the cell viability were comparable. The intraocular pressure (IOP) lowering effect was investigated in vivo using a modern rat ocular hypertensive model and elevated IOP reduction was seen in vivo with all the formulations. Notably, the reduction achieved in experimentally elevated IOP was comparable to that obtained with a marketed product. In conclusion, various BRA nanocrystal formulations, which all showed advantageous dissolution and absorption behavior, were successfully formulated.


Asunto(s)
Inhibidores de Anhidrasa Carbónica/administración & dosificación , Glaucoma/tratamiento farmacológico , Presión Intraocular/efectos de los fármacos , Nanopartículas , Sulfonamidas/administración & dosificación , Tiazinas/administración & dosificación , Administración Oftálmica , Animales , Rastreo Diferencial de Calorimetría , Inhibidores de Anhidrasa Carbónica/química , Inhibidores de Anhidrasa Carbónica/toxicidad , Línea Celular , Supervivencia Celular/efectos de los fármacos , Química Farmacéutica , Modelos Animales de Enfermedad , Epitelio Corneal/efectos de los fármacos , Epitelio Corneal/patología , Excipientes/química , Glaucoma/enzimología , Glaucoma/fisiopatología , Humanos , Derivados de la Hipromelosa/química , Masculino , Microscopía Electrónica de Rastreo , Nanotecnología , Tamaño de la Partícula , Polisorbatos/química , Ratas Wistar , Solubilidad , Sulfonamidas/química , Sulfonamidas/toxicidad , Propiedades de Superficie , Tecnología Farmacéutica/métodos , Tiazinas/química , Tiazinas/toxicidad , Factores de Tiempo
9.
Biomacromolecules ; 15(4): 1534-42, 2014 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-24628489

RESUMEN

We present two facile approaches for introducing multivalent displays of tyrosine sulfate mimetic ligands on the surface of cellulose nanocrystals (CNCs) for application as viral inhibitors. We tested the efficacy of cellulose nanocrystals, prepared either from cotton fibers or Whatman filter paper, to inhibit alphavirus infectivity in Vero (B) cells. Cellulose nanocrystals were produced by sulfuric acid hydrolysis leading to nanocrystal surfaces decorated with anionic sulfate groups. When the fluorescent marker expressing Semliki Forest virus vector, VA7-EGFP, was incubated with CNCs, strong inhibition of virus infectivity was achieved, up to 100 and 88% for cotton and Whatman CNCs, respectively. When surface sulfate groups of CNCs were exchanged for tyrosine sulfate mimetic groups (i.e. phenyl sulfonates), improved viral inhibition was attained. Our observations suggest that the conjugation of target-specific functionalities to CNC surfaces provides a means to control their antiviral activity. Multivalent CNCs did not cause observable in vitro cytotoxicity to Vero (B) cells or human corneal epithelial (HCE-T) cells, even within the 100% virus-inhibitory concentrations. Based on the similar chemistry of known polyanionic inhibitors, our results suggest the potential application of CNCs as inhibitors of other viruses, such as human immunodeficiency virus (HIV) and herpes simplex viruses.


Asunto(s)
Infecciones por Alphavirus/tratamiento farmacológico , Antivirales/química , Antivirales/farmacología , Celulosa/síntesis química , Nanopartículas/química , Nanotecnología/métodos , Virus de los Bosques Semliki/efectos de los fármacos , Tirosina/análogos & derivados , Animales , Biomimética , Celulosa/química , Chlorocebus aethiops , Epitelio Corneal/citología , Epitelio Corneal/efectos de los fármacos , Genes erbB-1 , Ligandos , Nanopartículas/toxicidad , Virus de los Bosques Semliki/genética , Espectroscopía Infrarroja por Transformada de Fourier , Tirosina/química , Células Vero/efectos de los fármacos , Células Vero/virología
10.
J Control Release ; 180: 109-16, 2014 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-24566254

RESUMEN

Nanoscience holds true promise in enabling efficient formulation development and in vivo delivery of poorly water soluble drugs. The objective of this study was to formulate solid oral nanocrystal delivery systems of itraconazole, and thus enhance the oral bioavailability of the very poorly soluble drug. Nanocrystal suspensions were prepared by a rapid wet milling technique, after which the suspensions were transformed into solid dosage forms by both freeze drying and granulating. Finally, the obtained nanocrystalline powders were capsule-packed as well as compacted to tablets. After in vitro analysis, the formulations (nanocrystal suspension (NPs), freeze dried NPs, granulated NPs) were tested in vivo in a rat model, and compared with commercial itraconazole formulation (Sporanox). Importantly, the results indicated rapid dissolution of the nanocrystalline itraconazole with enhanced bioavailability compared to physical mixture. Drug dissolution in vitro was immediate from NPs and freeze dried powder, and differed significantly from the marketed product (P=0.004 and 0.002, correspondingly) until 30min. Freeze drying was detected to be especially advantageous for the solid dosage forms. It is possible to maintain the original character of the nanocrystals, e.g. rapid dissolution, even after tableting of the nanocrystalline powders. Interestingly, the marketed product out-performed the nanocrystalline formulations in vivo, even though the nanocrystals provided reasonable bioavailability of itraconazole absorption as well. The efficient in vitro dissolution enhancement of the nanocrystalline formulations compared to Sporanox® was not realized in in vivo drug absorption.


Asunto(s)
Antifúngicos/administración & dosificación , Portadores de Fármacos/química , Itraconazol/administración & dosificación , Nanopartículas/química , Administración Oral , Animales , Antifúngicos/sangre , Itraconazol/sangre , Masculino , Ratas , Ratas Sprague-Dawley , Solubilidad
11.
Eur J Pharm Biopharm ; 87(1): 64-72, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24530427

RESUMEN

When nanocarriers are used for drug delivery they can often achieve superior therapeutic outcomes over standard drug formulations. However, concerns about their adverse effects are growing due to the association between exposure to certain nanosized particles and cardiovascular events. Here we examine the impact of intravenously injected drug-free nanocarriers on the cardiovasculature at both the systemic and organ levels. We combine in vivo and in vitro methods to enable monitoring of hemodynamic parameters in conscious rats, assessments of the function of the vessels after sub-chronic systemic exposure to nanocarriers and evaluation of the direct effect of nanocarriers on vascular tone. We demonstrate that nanocarriers can decrease blood pressure and increase heart rate in vivo via various mechanisms. Depending on the type, nanocarriers induce the dilation of the resistance arteries and/or change the responses induced by vasoconstrictor or vasodilator drugs. No direct correlation between physicochemical properties and cardiovascular effects of nanoparticles was observed. The proposed combination of methods empowers the studies of cardiovascular adverse effects of the nanocarriers.


Asunto(s)
Fenómenos Fisiológicos Cardiovasculares/efectos de los fármacos , Sistema Cardiovascular/efectos de los fármacos , Nanopartículas/efectos adversos , Nanotubos de Carbono/efectos adversos , Animales , Aorta Torácica/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Endotelio Vascular/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Técnicas In Vitro , Inyecciones Intravenosas , Masculino , Nanopartículas/administración & dosificación , Nanopartículas/química , Nanotubos de Carbono/química , Tamaño de la Partícula , Ácidos Polimetacrílicos/administración & dosificación , Ácidos Polimetacrílicos/efectos adversos , Ácidos Polimetacrílicos/química , Porosidad , Ratas Wistar , Silicio/administración & dosificación , Silicio/efectos adversos , Silicio/química , Propiedades de Superficie , Resistencia Vascular/efectos de los fármacos , Vasodilatación/efectos de los fármacos
12.
J Pharm Pharmacol ; 66(3): 367-77, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24206258

RESUMEN

OBJECTIVE: In general, the chemical and physical stability of amorphous cyclodextrin complexes and how storage affects their dissolution rate have not been widely reported. The aim of this study was to evaluate the solid-state stability of a fast-dissolving perphenazine/ß-cyclodextrin (ß-CD) complex, which has been found to be well absorbed after sublingual administration to rabbits. In addition, the dissolution rate of plain ß-CD in crystalline and amorphous forms was determined. METHODS: The amorphous perphenazine/ß-CD complex powders were prepared by spray-drying and freeze-drying, and their stability was examined after storage at 40°C, 75% relative humidity (RH) or at room temperature, 60% RH for up to 82 days. KEY FINDINGS: Perphenazine was found to be chemically stable in all samples. The dissolution rate of perphenazine remained practically unchanged at both storage conditions, although partial crystallization was observed in both spray-dried and freeze-dried samples at 40°C, 75% RH. Interestingly, it was also observed that the dissolution rates of crystalline and amorphous ß-CD were similar. CONCLUSION: The results suggest that CD complexation may represent a suitable alternative for preparing intraorally dissolving formulations because the fast dissolution rate of the drug was maintained even though changes in the crystal structure were observed during storage.


Asunto(s)
Estabilidad de Medicamentos , Excipientes/química , Perfenazina/química , beta-Ciclodextrinas/química , Administración Sublingual , Animales , Química Farmacéutica , Cristalización , Almacenaje de Medicamentos , Liofilización , Perfenazina/administración & dosificación , Polvos , Conejos , Solubilidad , beta-Ciclodextrinas/administración & dosificación
13.
Int J Pharm ; 454(1): 67-73, 2013 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-23834832

RESUMEN

Recently, mesoporous silicon (PSi) microparticles have been shown to extend the duration of action of peptides, reducing the need for frequent injections. Glucagon-like peptide 1 (GLP-1) is a potential novel treatment for type 2 diabetes. The aim of this study was to evaluate whether GLP-1 loading into PSi microparticles reduce blood glucose levels over an extended period. GLP-1 (pI 5.4) was loaded and released from the negatively charged thermally oxidized (TOPSi, pI 1.8) and thermally carbonized (TCPSi, pI 2.6) PSi microparticles and from the novel positively charged amine modified microparticles, designated as TOPSi-NH2-D (pI 8.8) and TCPSi-NH2-D (pI 8.8), respectively. The adsorption of GLP-1 onto the PSi microparticles could be increased 3-4-fold by changing the PSi surface charge from negative to positive, indicating that the positive surface charge of PSi promoted an electrostatic interaction between the negatively charged peptide. All the GLP-1 loaded PSi microparticles lowered the blood glucose levels after a single s.c. injection but surprisingly, TOPSi-NH2-D and TCPSi-NH2-D were not able to prolong the effect when compared to TOPSi, TCPSi or GLP-1 solution. However, TOPSi-NH2-D and TCPSi-NH2-D microparticles were able to carry improved payloads of active GLP-1 encouraging continuing further attempts to achieve sustained release.


Asunto(s)
Glucemia/efectos de los fármacos , Portadores de Fármacos , Péptido 1 Similar al Glucagón/farmacología , Hipoglucemiantes/farmacología , Silicio/química , Adsorción , Animales , Glucemia/metabolismo , Química Farmacéutica , Preparaciones de Acción Retardada , Péptido 1 Similar al Glucagón/administración & dosificación , Péptido 1 Similar al Glucagón/química , Péptido 1 Similar al Glucagón/metabolismo , Hipoglucemiantes/administración & dosificación , Hipoglucemiantes/química , Hipoglucemiantes/metabolismo , Inyecciones Subcutáneas , Masculino , Ratones , Ratones Endogámicos C57BL , Tamaño de la Partícula , Porosidad , Solubilidad , Propiedades de Superficie , Tecnología Farmacéutica/métodos , Factores de Tiempo
14.
Anal Chem ; 85(4): 2109-16, 2013 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-23320922

RESUMEN

Until recently, the freeze-drying process and formulation development have suffered from a lack of microscale analytical tools. Using such an analytical tool should decrease the required sample volume and also shorten the duration of the experiment compared to a laboratory scale setup. This study evaluated the applicability of Raman spectroscopy for in-line monitoring of a microscale freeze-drying process. The effect of cooling rate and annealing step on the solid-state formation of mannitol was studied. Raman spectra were subjected to principal component analysis to gain a qualitative understanding of the process behavior. In addition, mannitol solid-state form ratios were semiquantitatively analyzed during the process with a classical least-squares regression. A standard cooling rate of 1 °C/min with or without an annealing step at -10 °C resulted in a mixture of α, ß, δ, and amorphous forms of mannitol. However, a standard cooling rate induced the formation of mannitol hemihydrate, and a secondary drying temperature of +60 °C was required to transform the hemihydrate form to the more stable anhydrous polymorphs. A fast cooling rate of 10 °C/min mainly produced δ and amorphous forms of mannitol, regardless of annealing. These results are consistent with those from larger scale equipment. In-line monitoring the solid-state form of a sample is feasible with a Raman spectrometer coupled microscale freeze-drying stage. These results demonstrate the utility of a rapid, in-line, low sample volume method for the semiquantitative analysis of the process and formulation development of freeze-dried products on the microscale.


Asunto(s)
Liofilización , Manitol/química , Espectrometría Raman , Rastreo Diferencial de Calorimetría , Análisis de los Mínimos Cuadrados , Análisis de Componente Principal , Temperatura
15.
Anal Chem ; 85(4): 2377-84, 2013 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-23351045

RESUMEN

During the past decade, near-infrared (NIR) spectroscopy has been applied for in-line moisture content quantification during a freeze-drying process. However, NIR has been used as a single-vial technique and thus is not representative of the entire batch. This has been considered as one of the main barriers for NIR spectroscopy becoming widely used in process analytical technology (PAT) for freeze-drying. Clearly it would be essential to monitor samples that reliably represent the whole batch. The present study evaluated multipoint NIR spectroscopy for in-line moisture content quantification during a freeze-drying process. Aqueous sucrose solutions were used as model formulations. NIR data was calibrated to predict the moisture content using partial least-squares (PLS) regression with Karl Fischer titration being used as a reference method. PLS calibrations resulted in root-mean-square error of prediction (RMSEP) values lower than 0.13%. Three noncontact, diffuse reflectance NIR probe heads were positioned on the freeze-dryer shelf to measure the moisture content in a noninvasive manner, through the side of the glass vials. The results showed that the detection of unequal sublimation rates within a freeze-dryer shelf was possible with the multipoint NIR system in use. Furthermore, in-line moisture content quantification was reliable especially toward the end of the process. These findings indicate that the use of multipoint NIR spectroscopy can achieve representative quantification of moisture content and hence a drying end point determination to a desired residual moisture level.


Asunto(s)
Liofilización , Espectroscopía Infrarroja Corta/métodos , Agua/análisis , Calibración , Química Farmacéutica , Análisis de los Mínimos Cuadrados , Análisis de Componente Principal , Espectroscopía Infrarroja Corta/instrumentación , Espectroscopía Infrarroja Corta/normas , Agua/normas
16.
Eur J Pharm Sci ; 48(4-5): 680-8, 2013 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-23313622

RESUMEN

Continuous manufacturing methods offer economic and quality advantages when compared with batch manufacturing methods. In continuous manufacturing, one requires real time assurance of quality of product via the implementation of PAT tools. This study focuses on an in-line near-infrared (NIR) spectroscopic method for determining the drug content of powder mixtures and tablets during a continuous tableting process. Tablets consisting of acetaminophen (20-30%), lactose (69.07-78.93%) and magnesium stearate (0.93-1.07%) were prepared in a continuous direct compression line that consisted of two loss-in-weight feeders, one for acetaminophen and one for premixed lactose and magnesium stearate, and a continuous mixer followed by a rotary tablet press. NIR spectroscopy was applied to the continuous mixer and tablet press to perform a 100% product check at full tableting speed. The UV-spectrophotometric method was used as an off-line reference method to determine the acetaminophen content in the samples. The powder mixture and tablet samples were taken during the process for the calibration of continuous mixer and tablet press, respectively. For the continuous mixer, model creation with the PLS method yielded R-Square and RMSEC (root mean square error of calibration) values of 0.975% and 0.56%, respectively. For the tablet press, the corresponding R-Square and RMSEC values were 0.943% and 0.75%, respectively. A test run demonstrated good predictability in the estimation of the API content in the powder mixtures and tablets during the continuous tableting process. For the continuous mixer and tablet press, the RMSEP (root mean square error of prediction) values were 0.96% and 1.37%, respectively. This study demonstrates that an NIR instrument capable of fast spectra acquisition can be a valuable tool for the in-line monitoring of the continuous mixing and tableting processes.


Asunto(s)
Composición de Medicamentos/métodos , Polvos/química , Espectroscopía Infrarroja Corta/métodos , Comprimidos/química , Acetaminofén/análisis , Lactosa/análisis , Ácidos Esteáricos/análisis
17.
Int J Pharm ; 441(1-2): 248-54, 2013 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-23200957

RESUMEN

The aims were to prepare stable and well-dispersible pulmonary fine powders composed of combination drugs with different water solubility, to facilitate concomitant release of corticosteroid budesonide and short acting ß-agonist salbutamol sulphate and to improve the dissolution of the budesonide. The budesonide nanosuspensions were prepared by a wet milling which were mixed then with salbutamol sulphate, mannitol (bulking material) and leucine (coating material) for the preparation of micron-sized particles by an aerosol flow reactor wherein leucine formed a rough coating layer on particle surface. The stable and intact particle assemblies showed excellent aerosolization performance. The emitted doses from the inhaler, Easyhaler(®), were ~3 mg/dose with a coefficient variation of 0.1, and the fine particle fractions were ~50%. Complete dissolution of budesonide nanocrystals from the particles took place within 20 min with the same rate as salbutamol sulphate. Combining the two formulation technologies enabled the encapsulation of drugs with different solubility into a single, intact particle. The leucine coating provided excellent aerosolization properties which allowed fine powder delivery from the inhaler without carrier particles. This study showed the feasibility of preparing powders for combination therapy that are utilized, for instance, in inhalation therapy.


Asunto(s)
Albuterol/administración & dosificación , Budesonida/administración & dosificación , Sistemas de Liberación de Medicamentos , Excipientes/química , Administración por Inhalación , Aerosoles , Albuterol/química , Broncodilatadores/administración & dosificación , Broncodilatadores/química , Budesonida/química , Combinación de Medicamentos , Composición de Medicamentos , Estudios de Factibilidad , Glucocorticoides/administración & dosificación , Glucocorticoides/química , Leucina/química , Manitol/química , Nanopartículas , Nebulizadores y Vaporizadores , Tamaño de la Partícula , Solubilidad , Factores de Tiempo
18.
Drug Dev Ind Pharm ; 39(11): 1802-8, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23163644

RESUMEN

CONTEXT: Continuous processing is becoming popular in the pharmaceutical industry for its cost and quality advantages. OBJECTIVE: This study evaluated the mechanical properties, uniformity of dosage units and drug release from the tablets prepared by continuous direct compression process. MATERIALS AND METHODS: The tablet formulations consisted of acetaminophen (3-30% (w/w)) pre-blended with 0.25% (w/w) colloidal silicon dioxide, microcrystalline cellulose (69-96% (w/w)) and magnesium stearate (1% (w/w)). The continuous tableting line consisted of three loss-in-weight feeders and a convective continuous mixer and a rotary tablet press. The process continued for 8 min and steady state was reached within 5 min. The effects of acetaminophen content, impeller rotation rate (39-254 rpm) and total feed rate (15 and 20 kg/h) on tablet properties were examined. RESULTS AND DISCUSSION: All the tablets complied with the friability requirements of European Pharmacopoeia and rapidly released acetaminophen. However, the relative standard deviation of acetaminophen content (10% (w/w)) increased with an increase in impeller rotation rate at a constant total feed rate (20 kg/h). A compression force of 12 kN tended to result in greater tablet hardness and subsequently a slower initial acetaminophen release from tablets when compared with those made with the compression force of about 8 kN. CONCLUSIONS: In conclusion, tablets could be successfully prepared by a continuous direct compression process and process conditions affected to some extent tablet properties.


Asunto(s)
Acetaminofén/química , Analgésicos no Narcóticos/química , Celulosa/química , Excipientes/química , Modelos Moleculares , Dióxido de Silicio/química , Ácidos Esteáricos/química , Automatización , Fenómenos Químicos , Coloides , Composición de Medicamentos , Finlandia , Dureza , Cinética , Fenómenos Mecánicos , Control de Calidad , Solubilidad , Comprimidos , Tecnología Farmacéutica , Resistencia a la Tracción
19.
Mol Pharm ; 10(1): 353-9, 2013 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-23186283

RESUMEN

Porous silicon (PSi) is receiving growing attention in biomedical research, for example, in drug and peptide delivery. Inspired by several advantages of PSi, herein, thermally oxidized (TOPSi, hydrophilic), undecylenic acid-treated thermally hydrocarbonized (UnTHCPSi, moderately hydrophilic), and thermally hydrocarbonized (THCPSi, hydrophobic) PSi nanocarriers are investigated for sustained subcutaneous (sc) and intravenous (iv) peptide delivery. The route of administration is shown to affect drastically peptide YY3-36 (PYY3-36) release from the PSi nanocarriers in mice. Subcutaneous nanocarriers are demonstrated to be capable to sustain PYY3-36 delivery over 4 days, with the high absolute bioavailability values of PYY3-36. The pharmacokinetic parameters of PYY3-36 are presented to be similar between the sc PSi nanocarriers despite surface chemistry. In contrast, iv-delivered PSi nanocarriers display significant differences between the surface types. Overall, these results demonstrate the feasibility of PSi nanocarriers for the sustained sc delivery of peptides.


Asunto(s)
Portadores de Fármacos/química , Nanopartículas/administración & dosificación , Nanopartículas/química , Fragmentos de Péptidos/administración & dosificación , Fragmentos de Péptidos/química , Péptido YY/administración & dosificación , Péptido YY/química , Silicio/química , Administración Cutánea , Administración Intravenosa , Animales , Disponibilidad Biológica , Preparaciones de Acción Retardada/administración & dosificación , Preparaciones de Acción Retardada/química , Portadores de Fármacos/administración & dosificación , Sistemas de Liberación de Medicamentos , Ratones , Ratones Endogámicos BALB C , Porosidad , Silicio/administración & dosificación
20.
Duodecim ; 128(20): 2085-92, 2012.
Artículo en Finés | MEDLINE | ID: mdl-23167167

RESUMEN

Functionalities of biomaterials and drug delivery systems are improved by tailoring their surface properties using modern nanotechnology. Orthopedic implants and invasive electrodes are examples of implantable biomaterials. Biological interactions of orthopedic implants can be optimized by the synergetic effect of surface micro- and nanotexturing with a chemical composition of coating. Further, mechanical flexibility and electrochemical characteristics of invasive electrodes are improved by using micro- and nanotechnology. In nano-size drug delivery systems, surface properties of nanocarriers strongly affect their safety and efficacy. Mesoporous silicon nanoparticles are example of nanocarriers those properties can be tailored for drug delivery applications.


Asunto(s)
Sistemas de Liberación de Medicamentos , Nanotecnología , Prótesis e Implantes , Materiales Biocompatibles Revestidos/química , Electrodos , Nanopartículas/química , Silicio/química , Propiedades de Superficie
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA