Change search
Refine search result
1 - 6 of 6
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. Kjellman, T.
    et al.
    Xia, Xin
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK). Nanolog AB, Sweden.
    Alfredsson, V.
    Garcia-Bennett, Alfonso E.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Influence of microporosity in SBA-15 on the release properties of anticancer drug dasatinib2014In: Journal of materials chemistry. B, ISSN 2050-750X, E-ISSN 2050-7518, Vol. 2, no 32, p. 5265-5271Article in journal (Refereed)
    Abstract [en]

    The release of the hydrophobic cancer drug dasatinib from two mesoporous silica materials as drug delivery vehicles has been studied. One material is a reference 2D-hexagonal SBA-15 with the typical bimodal pore system with ordered primary mesopores and disordered intrawatI pores. The other material is a modified version of the same material where the intrawall porosity in the micropore regime has been selectively removed. Material characterization shows that, with the exception of the difference in intrawall porosity, the materials have identical properties. The drug dasatinib, a tyrosine kinase inhibitor, has been loaded, to the same extent, into the pores of both materials. The two materials give rise to very different release profiles of the drug. The presence of micropores leads to desired release properties: a high initial release of the drug, which is maintained over time. The lack of micropores also leads to a high initial release but followed by a rapid drop in the concentration of released drug, a consequence of its low solubility and hence crystallisation. We suggest that the presence of micropores in the carrier material, and the resultant kinetic release profile, leads to a stabilization of dasatinib in solution and to a sustained supersaturated level of the released drug. Our findings suggest that by controlling the mesoporous host with small variation in the textural properties, the kinetic release and crystallization behaviour of a drug can be altered. It is thus potentially possible to influence the drug post-release and thereby its bioavailability.

  • 2. Kupferschmidt, Natalia
    et al.
    Xia, Xin
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Labrador, Roberto H.
    Atluri, Rambabu
    Ballell, Lluis
    Garcia-Bennett, Alfonso E.
    In vivo oral toxicological evaluation of mesoporous silica particles2013In: Nanomedicine, ISSN 1743-5889, E-ISSN 1748-6963, Vol. 8, no 1, p. 57-64Article in journal (Refereed)
    Abstract [en]

    Background: Mesoporous silica particles are highly promising nanomaterials for biomedical applications. They can be used to improve bioavailability, solubility and drug stability and to protect drugs from the acidic conditions of the stomach, leading to increased drug effectiveness. Their biocompatibility in vivo has recieved little attention, in particular regarding oral administration. Aim: To study the oral tolerance of micron-sized nanoporous folic acid-templated material-1 (cylindrical, 2D hexagonal pore structure) and nanometer-sized anionic-surfactant-templated mesoporous silica material-6 (cylindrical, 3D cubic pore structure) mesoporous silica particles in Sprague Dawley rats. Materials & methods: A dose stepwise procedure or range finding test was followed by a consequent confirmatory test. The confirmatory test included daily administrations of 2000 and 1200 mg/kg doses for nanoporous folic acid-templated material-1 and anionic-surfactant-templated mesoporous silica material-6, respectively. Results: The maximum tolerated dose for anionic-surfactant-templated mesoporous silica material-6 was not reached. Similar results were observed for nanometer-sized anionic-surfactant-templated mesoporous silica material-1 in most of the animals, although adverse effects were observed in some animals that are most probably due to the administration by oral gavage of the formulated particles. Conclusion: The results are promising for the use of mesoporous silica materials as drug-delivery systems in oral administration.

  • 3.
    Xia, Xin
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Dissolving the Rocks: Solubility Enhancement of Active Pharmaceutical Ingredients using Mesoporous Silica2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Poor aqueous solubility is one of the greatest barriers for new drug candidates to enter toxicology studies, let alone clinical trials. This thesis focuses on contributing to solving this problem, evaluating the oral toxicity of mesoporous silica particles, and enhancing the apparent solubility and bioavailability of active pharmaceutical ingredients in vitro and in vivo using mesoporous silica particles.

    Toxicological studies in rats showed that two types of mesoporous silica particles given by oral administration were well tolerated without showing clinical signs of toxicity. Solubility enhancement, including in vivo bioavailability and in vitro intracellular activity, has been evaluated for selected drug compounds. Mesoporous silica was shown to effectively increase drug solubility by stabilizing the amorphous state of APIs, such as itraconazole (anti-fungal), dasatinib (anti-cancer), atazanavir (anti-HIV) and PA-824 (anti-tuberculosis). Itraconazole was successfully loaded into a variety of porous silica materials showing a distinct improvement in the dissolution properties in comparison to non-porous silica materials (and the free drug). Microporosity in SBA-15 particles has advantages in stabilizing the supersaturation state of dasatinib. Small pore sizes show better confinement of atazanavir, contributing to a higher dissolution of the drug compound. In the in vivo animal studies, NFM-1 loaded with atazanavir shows a four-fold increase in bioavailability compared to free crystalline atazanavir. PA-824 has a higher dissolution rate and solubility after loading into AMS-6 mesoporous particles. The loaded particles show similar antibacterial activity as the free PA-824.

    This thesis aims at highlighting some of the important factors enabling the selection of adequate mesoporous structures to enhance the pharmacokinetic profile of poorly water-soluble compounds, and preparing the scientific framework for uncovering the effects of drug confinement within mesopores of varying structural properties.

    Download full text (pdf)
    fulltext
  • 4.
    Xia, Xin
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK). Nanologica AB, Sweden.
    Pethe, Kevin
    Kim, Ryangyeo
    Ballell, Lluis
    Barros, David
    Cechetto, Jonathan
    Jeon, HeeKyoung
    Kim, Kideok
    Garcia-Bennett, Alfonso E.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Encapsulation of Anti-Tuberculosis Drugs within Mesoporous Silica and Intracellular Antibacterial Activities2014In: Nanomaterials, ISSN 2079-4991, Vol. 4, no 3, p. 813-826Article in journal (Refereed)
    Abstract [en]

    Tuberculosis is a major problem in public health. While new effective treatments to combat the disease are currently under development, they tend suffer from poor solubility often resulting in low and/or inconsistent oral bioavailability. Mesoporous materials are here investigated in an in vitro intracellular assay, for the effective delivery of compound PA-824; a poorly soluble bactericidal agent being developed against Tuberculosis (TB). Mesoporous materials enhance the solubility of PA-824; however, this is not translated into a higher antibacterial activity in TB-infected macrophages after 5 days of incubation, where similar values are obtained. The lack of improved activity may be due to insufficient release of the drug from the mesopores in the context of the cellular environment. However, these results show promising data for the use of mesoporous particles in the context of oral delivery with expected improvements in bioavailability.

  • 5.
    Xia, Xin
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK). Nanologica AB, Sweden.
    Zhou, Chunfang
    Ballell, Lluis
    Garcia-Bennett, Alfonso E.
    In vivo Enhancement in Bioavailability of Atazanavir in the Presence of Proton-Pump Inhibitors using Mesoporous Materials2012In: ChemMedChem, ISSN 1860-7179, E-ISSN 1860-7187, Vol. 7, no 1, p. 43-48Article in journal (Refereed)
  • 6.
    Xia, Xin
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zhou, Chunfang
    Nanologica AB.
    Feiler, Adam
    Nanologica AB.
    Systematic study of itraconazole in solubility enhancement and solid dispersion state using 3 different nanoporous silica particlesArticle in journal (Refereed)
1 - 6 of 6
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf