uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • 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
Effect of Lipids on Absorption of Carvedilol in Dogs: Is Coadministration of Lipids as Efficient as a Lipid-Based Formulation?
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
AstraZeneca R&D, Gothenburg, Sweden .
Show others and affiliations
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Lipid-based formulations (LBFs) is a formulation strategy for enabling oral delivery of poorly water-soluble drugs. However, current use of this strategy is limited to a few percent of the marketed products. Reasons for that are linked to the complexity of LBFs, chemical instability of pre-dissolved drug and a limited understanding of the influence of LBF intestinal digestion on drug absorption. The aim of this study was to explore intestinal drug solubilization from a long-chain LBF, and evaluate whether coadministration of LBF is as efficient as a lipid-based drug formulation containing the pre-dissolved model drug carvedilol. Thus, solubility studies of this weak base were performed in simulated intestinal fluid (SIF) and aspirated dog intestinal fluid (DIF). DIF was collected from duodenal stomas after dosing of water and two levels (1 g and 2 g) of LBF. Similarly, the in vitro SIF solubility studies were conducted prior to, and after addition of, undigested or digested LBF. The DIF fluid was further characterized for lipid digestion products (free fatty acid) and bile salt. Subsequently, carvedilol was orally administered to dogs in a lipid-based drug formulation and coadministered with LBF, and drug plasma exposure was assessed. In addition to these studies, in vitro drug absorption from the different formulation approaches were evaluated in a lipolysis-permeation device, and the obtained data was used to evaluate the in vitro in vivo correlation. The results showed elevated concentrations of free fatty acid and bile salt in the DIF when 2 g of LBF was administered, compared to only water. As expected, the SIF and DIF solubility data revealed that carvedilol solubilization increased by the presence of lipids and lipid digestion products. Moreover, coadministration of LBF and drug demonstrated equal plasma exposure to the lipid-based drug formulation. Furthermore, evaluation of in vitro absorption resulted in the same rank order for the LBFs as in the in vivo dog study. In conclusion, this study demonstrated increased intestinal solubilization from a small amount of LBF, caused by lipid digestion products and bile secretion. The outcomes also support the use of coadministration of LBF as a potential dosing regimen in cases where it is beneficial to have the drug in solid form, e.g. due to chemical instability in the lipid vehicle. Finally, the in vitro lipolysis-permeation used herein established IVIVC for carvedilol in the presence of LBFs.       

Keywords [en]
Intestinal digestion, in vivo dog study, lipid-based formulation, coadministration, absorption, in vitro in vivo correlation (IVIVC)
National Category
Pharmaceutical Sciences
Identifiers
URN: urn:nbn:se:uu:diva-366566OAI: oai:DiVA.org:uu-366566DiVA, id: diva2:1264933
Available from: 2018-11-21 Created: 2018-11-21 Last updated: 2018-11-21
In thesis
1. Improved Molecular Understanding of Lipid-Based Formulations: for Enabling Oral Delivery of Poorly Water-Soluble Drugs
Open this publication in new window or tab >>Improved Molecular Understanding of Lipid-Based Formulations: for Enabling Oral Delivery of Poorly Water-Soluble Drugs
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The majority of emerging drug candidates are not suited for conventional oral dosage forms, as they do not dissolve in the aqueous environment of the gastrointestinal (GI) tract. Consequently, a large number of enabling formulation strategies have emerged. One such strategy is to deliver the drug pre-dissolved in a lipid-based formulation (LBF), thereby bypassing the rate-limiting dissolution step. To date, only about 4% of the marketed oral drugs are delivered as LBFs. The limited use of this strategy is a result of the incomplete understanding of drug solubility in lipid vehicles, the reduced chemical stability of pre-dissolved drug, and the complex interplay between drug and formulation undergoing intestinal lipid processing. Hence, this thesis targeted an improved molecular understanding of lipid-based drug delivery to make an informed formulation development. In the first part of the thesis, drug solubility in LBF excipients and composed formulations was assessed. Through experimental studies of nearly forty compounds in nine excipients drug physicochemical properties related to solubility in these excipients were identified. The obtained data was used to develop in silico tools for prediction of drug solubility in excipients and formulations. The second part of the thesis focused on LBF performance in vitro and in vivo. Factors associated with the type of solid form that is precipitating during digestions was revealed, which provides an initial framework for understanding drug precipitation behaviour under physiological conditions. It was also shown that clinically relevant doses of LBF significantly increases intestinal drug solubilization as a result of GI lipid processing and bile secretion. Moreover, simultaneous assessment of digestion and absorption in vitro provided the same rank order of absorbed drug as the in vivo studies. Coadministration of LBF and drug was shown to be a promising alternative to pre-dissolved drug in the LBF. In summary, this thesis has improved the molecular understanding of factors that govern drug solubility in lipid vehicles and solid form of precipitated drug under digestive conditions. It was also proved that clinically relevant doses of LBFs significantly increase the intestinal drug solubilization, and proof-of-concept was shown for coadministration of LBF with solid drug as an alternative to drug-loaded LBF.  

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2018. p. 68
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Pharmacy, ISSN 1651-6192 ; 262
Keywords
lipid-based formulation, poorly water-soluble drug, solubility prediction, molecular properties, lipid digestion, precipitation, solid state, intestinal solubilization, in vitro in vivo correlation (IVIVC), coadministration
National Category
Pharmaceutical Sciences
Research subject
Pharmaceutical Science
Identifiers
urn:nbn:se:uu:diva-366586 (URN)978-91-513-0509-7 (ISBN)
Public defence
2019-01-18, B:42, Biomedical Center, Husargatan 3, Uppsala, 09:15 (English)
Opponent
Supervisors
Available from: 2018-12-20 Created: 2018-11-21 Last updated: 2019-01-21

Open Access in DiVA

No full text in DiVA

Authority records BETA

Alskär, Linda C.Parrow, AlbinKeemink, JannekeBergström, Christel A. S.

Search in DiVA

By author/editor
Alskär, Linda C.Parrow, AlbinKeemink, JannekeBergström, Christel A. S.
By organisation
Department of Pharmacy
Pharmaceutical Sciences

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 304 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • 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