In vitro and in vivo evaluation of ranitidine hydrochloride loaded hollow microspheres in rabbits

Wei, Yumeng; Zhao, Ling

doi:10.1007/s12272-001-2119-9

Cited by 21 publications

(20 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Tracking the in vivo floating behavior and location of dosage form through GI tract providing a broad insight for formulating the optimal floating drug delivery system could be established via radiography, gamma scintigraphy, gastroscopy, ultrasonography and magnetic resonance imaging. Considering the majority of the surveys in this case, not only the relevant correlation between in vivo and invitro assessments was confirmed but also effectiveness and reliability of these floating systems as an excellent strategy for controlled delivery of drugs was ascertained [Jain et al, 2006;Ali et al, 2007;Wei & Zhao, 2008;Guguloth et al, 2011].…”

Section: In Vivo Assessmentsmentioning

confidence: 70%

Novel Drug Delivery Systems for Modulation of Gastrointestinal Transit Time

Javadzadeh¹,

Hamedeyazdan²

2012

Recent Advances in Novel Drug Carrier Systems

View full text Add to dashboard Cite

Section: In Vivo Assessmentsmentioning

confidence: 70%

Novel Drug Delivery Systems for Modulation of Gastrointestinal Transit Time

Javadzadeh¹,

Hamedeyazdan²

2012

Recent Advances in Novel Drug Carrier Systems

View full text Add to dashboard Cite

“…The microspheres were separated by filtration, washed with water and dried at room temperature in a desiccators for 24 hours. Wei et al (2008) prepared hollow microspheres by using liquid paraffin as an external phase. Microspheres possessing an internal hollow structure were prepared using an oil-in-oil (o/o) emulsion solvent diffusionevaporation method.…”

Section: Methods Of Preparation Of Hollow Microspheresmentioning

confidence: 99%

“…When viscosity is increased, the yield of hollow microspheres is decreased, and mean diameter and drug loading amount are increased (Wei, Zhao, 2008). Baykara and Kiliçarslan (2003) have studied the effect of the drug-to-polymer ratio on the properties of verapamil HCl loaded microspheres.…”

Section: Amount Of Polymer and Viscositymentioning

confidence: 99%

“…Samples are withdrawn at a specified time interval and analyzed by any suitable analytical method, such as UV spectroscopy or HPLC, etc. Wei et al (2008) used the same apparatus with the following modifications: the microspheres were intro-duced into a dialysis membrane bag with molecular weight cut off of 8000-12000. The test bag, which was tied and bound to the rotating paddle by a thread, was immersed in the dissolution medium; the rotating speed was 100 rpm.…”

Section: In Vitro Release Studiesmentioning

confidence: 99%

“…The animals are fasted for 24 hours before the experiments; however, they are given free access to food and water during the experiments. Blood samples (2 mL) are collected from the marginal ear vein into heparinized centrifuge at an appropriate time interval (Wei, Zhao, 2008;Joseph, Lakshmi, Jayakrishnan, 2002). Sato et al (2003a) has carried out an in vivo study in healthy human volunteers.…”

Section: In Vivo Studiesmentioning

confidence: 99%

See 2 more Smart Citations

Floating microspheres: a review

Mukund

Kantilal

Sudhakar

2012

Braz. J. Pharm. Sci.

View full text Add to dashboard Cite

Gastric emptying is a complex process, one that is highly variable and that makes in vivo performance of drug delivery systems uncertain. A controlled drug delivery system with prolonged residence time in the stomach can be of great practical importance for drugs with an absorption window in the upper small intestine. The main limitations are attributed to the inter-and intra-subject variability of gastrointestinal (GI) transit time and to the non-uniformity of drug absorption throughout the alimentary canal. Floating or hydrodynamically controlled drug delivery systems are useful in such applications. Various gastroretentive dosage forms are available, including tablets, capsules, pills, laminated films, floating microspheres, granules and powders. Floating microspheres have been gaining attention due to the uniform distribution of these multiple-unit dosage forms in the stomach, which results in more reproducible drug absorption and reduced risk of local irritation. Such systems have more advantages over the single-unit dosage forms. The present review briefly addresses the physiology of the gastric emptying process with respect to floating drug delivery systems. The purpose of this review is to bring together the recent literature with respect to the method of preparation, and various parameters affecting the performance and characterization of floating microspheres.Uniterms: Floating microspheres. Emulsion solvent diffusion-evaporation method. Drug delivery system. Release modifiers.O esvaziamento gástrico é um processo complexo, com elevada variabilidade e responsável pela incerteza do desempenho dos medicamentos in vivo. Dessa forma, os sistemas de liberação modificada de fármacos, com tempo de residência prolongado no estômago, em especial, considerando aqueles fármacos com janela de absorção na porção superior do intestino delgado, apresentam fundamental importância. As principais limitações relativas à absorção do fármaco são, no geral, atribuídas à variabilidade inter e intra-paciente do tempo de trânsito gastro-intestinal (GI) e da não-uniformidade da absorção do fármaco na extensão do canal alimentar. Assim, justifica-se a utilização dos sistemas flutuantes ou hidrodinâmicos de liberação de fármacos. Vários medicamentos gastrorretentivos estão disponibilizados no mercado e incluem comprimidos, cápsulas, pílulas, filmes laminados, microesferas flutuantes, grânulos e pós. As microesferas flutuantes apresentam maior destaque em função da distribuição granulométrica uniforme dessas formulações de dose múltipla. Como resultado, a absorção do fármaco apresenta maior reprodutibilidade e os riscos associados à irritação local são reduzidos. Tais sistemas apresentam maior vantagem quando comparado às formulações de dose única. A presente revisão tem como objetivo apresentar as publicações recentes referentes aos métodos de preparação, os vários parâmetros que afetam o desempenho e a caracterização das microesferas flutuantes. Além disso, o presente trabalho aborda a fisiologia do processo de esvaziamento gást...

show abstract

Polymer blends used to prepare nifedipine loaded hollow microspheres for a floating-type oral drug delivery system: In vitro evaluation

Zhao

Wei

et al. 2010

Arch. Pharm. Res.

Self Cite

View full text Add to dashboard Cite

The aim of this study was to investigate whether hollow microspheres prepared from polymer blends of polyvinyl pyrrolidone (PVP) and ethyl cellulose (EC) could improve the vitro release behavior of the poorly water-soluble drug nifedipine. Hollow microspheres containing nifedipine were prepared by a solvent diffusion-evaporation method using various ratios of PVP and EC codissolved with drug in ethanol/ether (5:1, v/v). The hollow microspheres could float in release medium for more than 24 h, and floating capacities were not be influenced by mixing PVP. In vitro release profiles of hollow microspheres prepared using EC along showed an initial burst release to some extent, and the cumulative release percentage was less than 55% after 24 h. But, not only the slope but also the shape of the release curves was affected by using mixture of PVP and EC. What's more important, when the ratio (PVP/EC) increased to 1.5:8.5, the cumulative release percentage could be increased to 95.8%. Furthermore, the release rate of microspheres showed a zero order approximate dynamic model and could be expressed by the following equation: Q=3.78t+8.52 (r=0.990). Consequently, hollow microspheres prepared using polymer blends of PVP and EC (1.5:8.5, w/w) could be suitable for floating-type controlled-release delivery systems for the oral administration of nifedipine.

show abstract

In vitro and in vivo evaluation of ranitidine hydrochloride loaded hollow microspheres in rabbits

Cited by 21 publications

References 18 publications

Novel Drug Delivery Systems for Modulation of Gastrointestinal Transit Time

Novel Drug Delivery Systems for Modulation of Gastrointestinal Transit Time

Floating microspheres: a review

Polymer blends used to prepare nifedipine loaded hollow microspheres for a floating-type oral drug delivery system: In vitro evaluation

Contact Info

Product

Resources

About