Oral modified-release formulations in motion: The relationship between gastrointestinal transit and drug absorption

Varum, Felipe; Merchant, Hamid A.; Basit, Abdul W.

doi:10.1016/j.ijpharm.2010.04.046

Cited by 93 publications

(44 citation statements)

References 93 publications

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“…The extent of fasted/fed state is however critical to the performance of the drug carrier 51 via its influence on gastro-intestinal transit time, pH, contents and availability of water, and 52 microbial enzymatic activity, to mention but a few factors (Varum, Merchant et al 2010; 53 Scott, Gratz et al 2013; Varum, Hatton et al 2013). This is particularly obvious for orally 54 administered colonic prodrugs, whose onset of absorption depends not only on their physico-55 chemical properties, but also on the time taken for the prodrug to reach the colon, and on the 56 rate of pH/microbial enzyme -controlled drug release.…”

mentioning

confidence: 99%

Influence of feeding regimens on rat gut fluids and colonic metabolism of diclofenac-β-cyclodextrin

Vieira

Murdan

Serra

et al. 2014

Carbohydrate Polymers

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Influence of feeding regimens on rat gut fluids and colonic metabolism of diclofenac-rmbeta-cyclodextrin, Carbohydrate Polymers (2014), http://dx.doi.org/10. 1016/j.carbpol.2014.06.064 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. and ii) metabolism of two colonic prodrugs, diclofenac-β-cyclodextrin and a commercially 26 available control, sulfasalazine, within the caecal and colonic contents. Male Wistar rats were 27 subject to four different feeding regimens, the gut contents characterized (mass and pH) and 28 the metabolism of prodrugs investigated. 29The feeding regimen affects gut contents (mass and pH), more specifically in the stomach 30 and lower intestine, and affects the rate of metabolism of diclofenac-β-cyclodextrin, but not 31 that of sulfasalazine. The latter's degradation is much faster than that of diclofenac-β-

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mentioning

confidence: 99%

Influence of feeding regimens on rat gut fluids and colonic metabolism of diclofenac-β-cyclodextrin

Vieira

Murdan

Serra

et al. 2014

Carbohydrate Polymers

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“…The hypothesis validation in animals was not possible because this was a specific case of modeling gastric emptying behavior and passage of a large dosage unit from the antral region of the stomach. Both correlate poorly between different animal species and with humans (20). In addition, a human study utilizing gamma scintigraphy, magnetic marker, or other in vivo imaging technology to monitor gastric retention was prohibitively expensive.…”

Section: In Vitro Prediction By Usp Apparatusmentioning

confidence: 99%

A Formulation Case Study Comparing the Dynamic Gastric Model with Conventional Dissolution Methods

Mann¹,

Pygall²

2012

Dissolution Technol.

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Even in the 21st century, conventional compendial dissolution testing remains a key cornerstone of the drug development process and quality control testing. However, opportunities exist with respect to in vitro technology developments that provide the potential for formulation and analytical scientists to exceed the capabilities of the conventional dissolution test toward a more biorelevant testing regime. This work presents a product development case study in which bioequivalence was observed between an immediate-release (IR) innovator product and a comparative singlelayer reference product. Despite this, when the constituent granule of the comparative single-layer reference product was formulated in a bilayer formulation with a nondisintegrating second layer, bioequivalence versus the innovator was not achieved. The use of USP Apparatus 2 dissolution testing failed to predict the bioequivalence failure, and hence an investigation was undertaken to develop a mechanistic understanding of in vivo behavior. Using both USP Apparatus 4 dissolution in the open-loop configuration and the dynamic gastric model (a novel in vitro model designed to mimic the human stomach), an understanding of the dissolution and disintegration properties of the reference product was established. The insights gained using novel technology facilitated the redesign and subsequent improvement in pharmacokinetic parameters of a complex pharmaceutical dosage form.

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“…Nevertheless, there are still gaps in our knowledge on GI physiology to move forward effectively in developing more reliable therapeutic systems (1,81). Non-invasive techniques are responding to the demands to improve our fundamental understanding for providing information on drug delivery and its relationships at specific organs.…”

Section: Presystemic Metabolismmentioning

confidence: 99%

Biomagnetic Methods: Technologies Applied to Pharmaceutical Research

et al. 2010

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Biomagnetic methods have been designed for a wide range of applications. Recently, such methods have been proposed as alternatives to scintigraphy for evaluating of a number of pharmaceutical processes in vitro as well as under the influence of gastrointestinal physiological parameters. In this review, physical characterization as well as the most recent applications of Superconducting Quantum Interference Device (SQUID), Anisotropic Magnetoresistive (AMR) and AC Biosusceptometry (ACB) in the pharmaceutical research will be explored. Moreover, their current status and how these technologies can be employed to improve the knowledge about the impact of gastrointestinal physiology on drug delivery in association with pharmacokinetic outcomes, termed pharmacomagnetography, will be presented.

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Oral modified-release formulations in motion: The relationship between gastrointestinal transit and drug absorption

Cited by 93 publications

References 93 publications

Influence of feeding regimens on rat gut fluids and colonic metabolism of diclofenac-β-cyclodextrin

Influence of feeding regimens on rat gut fluids and colonic metabolism of diclofenac-β-cyclodextrin

A Formulation Case Study Comparing the Dynamic Gastric Model with Conventional Dissolution Methods

Biomagnetic Methods: Technologies Applied to Pharmaceutical Research

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