Intrinsic lipolysis rate for systematic design of lipid-based formulations

Lipid-based formulations (LBFs) are used by the pharmaceutical industry in oral delivery systems for both poorly water-soluble drugs and biologics. Digestibility is key for the performance of LBFs and in vitro lipolysis is commonly used to compare the digestibility of LBFs. Results from in vitro lipolysis experiments depend highly on the experimental conditions and formulation characteristics, such as droplet size (which defines the surface area available for digestion) and interfacial structure. This study introduced the intrinsic lipolysis rate (ILR) as a surface area-independent approach to compare lipid digestibility.

The data contained in this dataset has been collected in the period from July 2021 until March 2022 at the Biomedical Center (BMC), Uppsala University.

The dataset contains two types of data: 1) dynamic light scattering (DLS) measurements of acylglycerol nanoemulsion droplets and 2) in vitro pH stat lipolysis data obtained from the digestion of acylglycerol nanoemulsions. 

Nineteen acylglycerol nanoemulsions were prepared with polysorbate 80 as stabilizer and digested in vitro. The experiments were conducted in triplicate. The data contained in this dataset is arranged in folders representing the nineteen acylglycerol nanoemulsions. The folder title gives information about the acylglycerol in the nanoemulsion and the concentration of polysorbate 80 used to stabilize the nanoemulsion. 

The hydrodynamic diameter of the nanoemulsion droplets was measured using a Litesizer 500 (Anton Paar, Graz, Austria). DLS measurements were conducted at 37 °C using the instrument’s automatic setting for adjustment of the focus and measurement angle. 

The in vitro pH stat lipolysis was conducted using a titrator (907 Titrando, Metrohm, Herisau, Switzerland) connected to a 10 ml burette, a pH electrode (iUnitrode with Pt 1000, Metrohm, Herisau, Switzerland) and a propeller stirrer. Lipolysis was conducted for 90 min using 0.6 M NaOH as the titrant when digesting nanoemulsions and 0.2 M NaOH when digesting the lipolysis medium (i.e., fasted state simulated intestinal fluid) without nanoemulsion (‘blank’). After lipolysis, the pH was rapidly raised to 9 to estimate the amount of unionized fatty acids (i.e., termed ‘back titration’; BT).