| 1. |
- Albrecht, Karin, et al.
(författare)
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In Vivo Investigation of Thiomer-Polyvinylpyrrolidon Nanoparticles Using Magnetic Resonance Imaging
- 2010
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Ingår i: Journal of Pharmaceutical Sciences. - : Wiley Inter Science. - 0022-3549 .- 1520-6017. ; 99:4, s. 2008-2017
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Tidskriftsartikel (refereegranskat)abstract
- This study focused on the investigation of the permeation enhancing effects of a stomach targeted, nanoparticulate drug delivery system. The polyacrylic acid–cysteine/polyvinylpyrrolidon nanoparticles were loaded with the magnetic resonance imaging (MRI) contrast agent diethylenetriaminepentaacetic acid gadolinium( III)dihydrogen salt (Gd-DTPA). Average particle size was determined to be 130nm and the optimum for stability was found to be below a pH of 4.5. In vitro permeation studies were performed on rat gastric mucosa and revealed an eightfold increase in Gd- DTPA uptake when incorporated in the nanoparticles compared to evaluation in the presence of unformulated polyacrylic acid–cysteine. In vivo investigations with rats were performed via the noninvasive MRI method in order to track the nanoparticles way through the gastrointestinal tract. When Gd-DTPA was administered orally as nanoparticulate suspension, an increased MRI signal in the urinary bladder was detected after 34 min, providing evidence for systemic uptake and renal elimination of the contrast agent. As control experiments with Gd-DTPA only or in combination with unformulated polyacrylic acid–cysteine revealed no MRI signal increase at all, the significant permeation enhancing effect could be identified based on the nanoparticulate formulation.
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| 2. |
- Boyd, Ben J., et al.
(författare)
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Successful oral delivery of poorly water-soluble drugs both depends on the intraluminal behavior of drugs and of appropriate advanced drug delivery systems
- 2019
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Ingår i: European Journal of Pharmaceutical Sciences. - : ELSEVIER. - 0928-0987 .- 1879-0720. ; 137
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Tidskriftsartikel (refereegranskat)abstract
- Poorly water-soluble drugs continue to be a problematic, yet important class of pharmaceutical compounds for treatment of a wide range of diseases. Their prevalence in discovery is still high, and their development is usually limited by our lack of a complete understanding of how the complex chemical, physiological and biochemical processes that occur between administration and absorption individually and together impact on bioavailability. This review defines the challenge presented by these drugs, outlines contemporary strategies to solve this challenge, and consequent in silico and in vitro evaluation of the delivery technologies for poorly water-soluble drugs. The next steps and unmet needs are proposed to present a roadmap for future studies for the field to consider enabling progress in delivery of poorly water-soluble compounds.
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| 3. |
- Vinarov, Zahari, et al.
(författare)
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Current challenges and future perspectives in oral absorption research : An opinion of the UNGAP network
- 2021
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Ingår i: Advanced Drug Delivery Reviews. - : Elsevier. - 0169-409X .- 1872-8294. ; 171, s. 289-331
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Forskningsöversikt (refereegranskat)abstract
- Although oral drug delivery is the preferred administration route and has been used for centuries, modern drug discovery and development pipelines challenge conventional formulation approaches and highlight the insufficient mechanistic understanding of processes critical to oral drug absorption. This review presents the opinion of UNGAP scientists on four key themes across the oral absorption landscape: (1) specific patient populations, (2) regional differences in the gastrointestinal tract, (3) advanced formulations and (4) food-drug interactions. The differences of oral absorption in pediatric and geriatric populations, the specific issues in colonic absorption, the formulation approaches for poorly water-soluble (small molecules) and poorly permeable (peptides, RNA etc.) drugs, as well as the vast realm of food effects, are some of the topics discussed in detail. The identified controversies and gaps in the current understanding of gastrointestinal absorption-related processes are used to create a roadmap for the future of oral drug absorption research.
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