Improving Correlations Between Drug Solubilization and In Vitro Lipolysis by Monitoring the Phase Partitioning of Lipolytic Species for Lipid-Based Formulations
Journal article, 2019

Solution proton nuclear magnetic resonance analysis was used in conjunction with in vitro lipolysis to elucidate the time-dependent speciation and release of lipolytic products during the digestion of lipid-loaded inorganic particles, allowing correlations to be made between the phase partitioning of lipolytic products and an encapsulated poorly soluble drug. Silicon dioxide, montmorillonite, and laponite were used to encapsulate medium chain triglycerides into solid-state lipid-based formulations (LBFs), and coumarin 102 was selected as a model poorly soluble compound. The specific inorganic carrier material used to encapsulate medium chain triglycerides significantly impacted the release and partitioning of the solubilizing lipolytic products, that is, diglycerides, monoglycerides, and fatty acids. A strong linear correlation was obtained between drug solubilization and fatty acid release to the aqueous phase (R2 = 0.996), indicating fatty acids to be the most important lipid species for enabling solubilization and potential drug absorption in vivo. This method was developed to improve upon the use of pH-stat titration for characterizing LBF digestion during in vitro lipolysis studies and is demonstrated herein to provide useful insights into how the selected inorganic carrier material impacts LBF performance when solid-state LBF powders are fabricated via adsorption.

lipid-based formulation(s)

in vitro model(s)

oral drug delivery


dissolution model(s)

poorly water-soluble drug(s)




drug delivery system(s)


Tahnee J. Dening

University of South Australia

Paul Joyce

Chalmers, Physics, Biological Physics

University of South Australia

Clive A. Prestidge

University of South Australia

Journal of Pharmaceutical Sciences

0022-3549 (ISSN) 15206017 (eISSN)

Vol. 108 1 295-304

Subject Categories

Pharmaceutical Sciences

Analytical Chemistry

Other Chemistry Topics





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