The Experts below are selected from a list of 2760 Experts worldwide ranked by ideXlab platform
Katherine Briggs - One of the best experts on this subject based on the ideXlab platform.
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application of an artificial stomach Duodenum reduced gastric pH dog model for formulation principle assessment and mechanistic performance understanding
Journal of Pharmaceutical Sciences, 2017Co-Authors: Chenming Lee, Paul E Luner, Karen Locke, Katherine BriggsAbstract:Abstract The objective of this study was to develop an artificial stomach-Duodenum (ASD) dissolution model as an in vitro evaluation tool that would simulate the gastrointestinal pHysiology of gastric pH-reduced dogs as a method to assess formulations for a poorly soluble free acid compound with ng/mL solubility. After establishing the ASD model with well-controlled Duodenum pH, 5 formulations each applying different solubilization principles were developed and their performance in the ASD model and in vivo in dogs was evaluated. Excellent correlations were obtained between dog area under the curve (AUC) and ASD AUC of 5 formulations evaluated with simulated intestinal fluid (r 2 = 0.987) and fasted-state simulated intestinal fluid (r 2 = 0.989) as the Duodenum dissolution medium, indicating that the approach of infusing NaOH into Duodenum compartment to maintain Duodenum pH of an ASD worked properly in simulating gastric pH–reduced dog. Raman spectroscopy was used to study drug dissolution kinetics associated with different solubilization principles and the results suggested that the solubilization principles performed as designed. Spectroscopic results also identified that the compound formed a gel during dissolution and hypromellose maintained the drug-gelled state to avoid further solid form conversion. The implication of the compound pHysical gelation to drug dissolution kinetics and in vivo exposure are discussed.
Chenming Lee - One of the best experts on this subject based on the ideXlab platform.
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application of an artificial stomach Duodenum reduced gastric pH dog model for formulation principle assessment and mechanistic performance understanding
Journal of Pharmaceutical Sciences, 2017Co-Authors: Chenming Lee, Paul E Luner, Karen Locke, Katherine BriggsAbstract:Abstract The objective of this study was to develop an artificial stomach-Duodenum (ASD) dissolution model as an in vitro evaluation tool that would simulate the gastrointestinal pHysiology of gastric pH-reduced dogs as a method to assess formulations for a poorly soluble free acid compound with ng/mL solubility. After establishing the ASD model with well-controlled Duodenum pH, 5 formulations each applying different solubilization principles were developed and their performance in the ASD model and in vivo in dogs was evaluated. Excellent correlations were obtained between dog area under the curve (AUC) and ASD AUC of 5 formulations evaluated with simulated intestinal fluid (r 2 = 0.987) and fasted-state simulated intestinal fluid (r 2 = 0.989) as the Duodenum dissolution medium, indicating that the approach of infusing NaOH into Duodenum compartment to maintain Duodenum pH of an ASD worked properly in simulating gastric pH–reduced dog. Raman spectroscopy was used to study drug dissolution kinetics associated with different solubilization principles and the results suggested that the solubilization principles performed as designed. Spectroscopic results also identified that the compound formed a gel during dissolution and hypromellose maintained the drug-gelled state to avoid further solid form conversion. The implication of the compound pHysical gelation to drug dissolution kinetics and in vivo exposure are discussed.
Paul E Luner - One of the best experts on this subject based on the ideXlab platform.
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application of an artificial stomach Duodenum reduced gastric pH dog model for formulation principle assessment and mechanistic performance understanding
Journal of Pharmaceutical Sciences, 2017Co-Authors: Chenming Lee, Paul E Luner, Karen Locke, Katherine BriggsAbstract:Abstract The objective of this study was to develop an artificial stomach-Duodenum (ASD) dissolution model as an in vitro evaluation tool that would simulate the gastrointestinal pHysiology of gastric pH-reduced dogs as a method to assess formulations for a poorly soluble free acid compound with ng/mL solubility. After establishing the ASD model with well-controlled Duodenum pH, 5 formulations each applying different solubilization principles were developed and their performance in the ASD model and in vivo in dogs was evaluated. Excellent correlations were obtained between dog area under the curve (AUC) and ASD AUC of 5 formulations evaluated with simulated intestinal fluid (r 2 = 0.987) and fasted-state simulated intestinal fluid (r 2 = 0.989) as the Duodenum dissolution medium, indicating that the approach of infusing NaOH into Duodenum compartment to maintain Duodenum pH of an ASD worked properly in simulating gastric pH–reduced dog. Raman spectroscopy was used to study drug dissolution kinetics associated with different solubilization principles and the results suggested that the solubilization principles performed as designed. Spectroscopic results also identified that the compound formed a gel during dissolution and hypromellose maintained the drug-gelled state to avoid further solid form conversion. The implication of the compound pHysical gelation to drug dissolution kinetics and in vivo exposure are discussed.
Karen Locke - One of the best experts on this subject based on the ideXlab platform.
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application of an artificial stomach Duodenum reduced gastric pH dog model for formulation principle assessment and mechanistic performance understanding
Journal of Pharmaceutical Sciences, 2017Co-Authors: Chenming Lee, Paul E Luner, Karen Locke, Katherine BriggsAbstract:Abstract The objective of this study was to develop an artificial stomach-Duodenum (ASD) dissolution model as an in vitro evaluation tool that would simulate the gastrointestinal pHysiology of gastric pH-reduced dogs as a method to assess formulations for a poorly soluble free acid compound with ng/mL solubility. After establishing the ASD model with well-controlled Duodenum pH, 5 formulations each applying different solubilization principles were developed and their performance in the ASD model and in vivo in dogs was evaluated. Excellent correlations were obtained between dog area under the curve (AUC) and ASD AUC of 5 formulations evaluated with simulated intestinal fluid (r 2 = 0.987) and fasted-state simulated intestinal fluid (r 2 = 0.989) as the Duodenum dissolution medium, indicating that the approach of infusing NaOH into Duodenum compartment to maintain Duodenum pH of an ASD worked properly in simulating gastric pH–reduced dog. Raman spectroscopy was used to study drug dissolution kinetics associated with different solubilization principles and the results suggested that the solubilization principles performed as designed. Spectroscopic results also identified that the compound formed a gel during dissolution and hypromellose maintained the drug-gelled state to avoid further solid form conversion. The implication of the compound pHysical gelation to drug dissolution kinetics and in vivo exposure are discussed.
Villalba Gimeno Anna - One of the best experts on this subject based on the ideXlab platform.
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Desarrollo de un sistema de medida de la liberación de compuestos encapsulados en matriz de alginato cálcico por espectrofotometría de radiofrecuencia
'Universitat Politecnica de Valencia', 2019Co-Authors: Villalba Gimeno AnnaAbstract:[ES] La creciente preocupación de la industria alimentaria de suministrar productos alimenticios que suplan las necesidades digestivas debido a los problemas existentes relacionados con la absorción, hace que la investigación y el empleo de otras técnicas como es la microencapsulación tengan una relevante importancia y jueguen un papel esencial. Se encapsuló hierro electrolítico con vitamina C en matriz de alginato cálcico mediante goteo controlado por gelatinización iónica. Con el fin de cuantificar la liberación de compuestos encapsulados se ha diseñado una cámara de medida de propiedades dieléctricas mediante espectrofotometría en radiofrecuencia. De esta manera es posible cuantificar la presencia de compuestos con elevada fuerza iónica en medio líquido (disolución de ácido clorhídrico y agua a pH de estómago y de duodeno), trabajando en el rango de la radiofrecuencia. Se han determinado las propiedades dieléctricas de la liberación del hierro cuando se simulan las condiciones gástricas en la cámara de determinación a temperatura controlada. El sistema de monitorización ha sido capaz de determinar tanto los contenidos en vitamina C como de hierro electrolítico, además ha sido posible cuantificar la velocidad de liberación de encapsulaciones de hierro y vitamina C en matriz de alginato cálcico.[EN] The growing concern of the food industry to produce new food products to supply products without digestive absorption problems, due to existing problems related to absorption of some electrolytes, makes the research and use of other techniques such as microencapsulation have a relevant importance and play an essential role in the design of new food products. Electrolytic iron was encapsulated with vitamin C in a calcium alginate matrix by dripping controlled by ionic gelation. In order to quantify the release of encapsulated compounds, a chamber for measuring dielectric properties has been designed by radiofrequency spectropHotometry. In this way it is possible to quantify the presence of compounds with high ionic strength in liquid medium (hydrochloric acid solution and water at stomach and Duodenum pH), working in the radiofrequency range. The dielectric properties of iron release have been determined when gastric conditions are simulated in the chamber of determination in a temperature controlled chamber. The monitoring system has been able to determine both the contents of vitamin C and electrolytic iron, it has also been possible to quantify the rate of release of encapsulations of iron and vitamin C in a calcium alginate matrix.[CA] La creixent preocupació de la indústria alimentària per subministrar productes alimentaris que reemplacen les necessitats digestives a causa dels problemes existents relacionats amb l'absorció, fa que la investigació i l'ocupació d'altres tècniques com és la microencapsulació tinguen una rellevant importància i juguen un paper essencial. Es va encapsular ferro electrolític amb vitamina C en una matriu d'alginat càlcic per mitjà de goteig controlat mitjançant la tècnica de gelatinització iònica. A fi de quantificar l'alliberament dels compostos encapsulats s'ha dissenyat una cambra de mesura de propietats dielèctriques per mitjà d'espectrofotometria en radiofreqüència. D’aquesta manera és possible quantificar la presència de compostos amb elevada força iònica al medi líquid (dissolució d'àcid clorhídric i aigua a pH d'estómac i de duodè) , treballant en el rang de la radiofreqüència. S'han determinat les propietats dielèctriques de l'alliberament del ferro quan se simulen les condicions gàstriques en la cambra de determinació a temperatura controlada. El sistema de monitorització ha sigut capaç de determinar tant els continguts en vitamina C com de ferro electrolític, a més ha sigut possible quantificar la velocitat d'alliberament de les encapsulacions de ferro i vitamina C en una matriu d'alginat càlcic.Villalba Gimeno, A. (2019). Desarrollo de un sistema de medida de la liberación de compuestos encapsulados en matriz de alginato cálcico por espectrofotometría de radiofrecuencia. http://hdl.handle.net/10251/127238TFG
