Identification
of the usefulness of lipid-based formulations (LBFs)
for delivery of poorly water-soluble drugs is at date mainly experimentally
based. In this work we used a diverse drug data set, and more than
2,000 solubility measurements to develop experimental and computational
tools to predict the loading capacity of LBFs. Computational models
were developed to enable in silico prediction of
solubility, and hence drug loading capacity, in the LBFs. Drug solubility
in mixed mono-, di-, triglycerides (Maisine 35-1 and Capmul MCM EP)
correlated (R2 0.89) as well as the drug
solubility in Carbitol and other ethoxylated excipients (PEG400, R2 0.85; Polysorbate 80, R2 0.90; Cremophor EL, R2 0.93).
A melting point below 150 °C was observed to result in a reasonable
solubility in the glycerides. The loading capacity in LBFs was accurately
calculated from solubility data in single excipients (R2 0.91). In silico models, without the
demand of experimentally determined solubility, also gave good predictions
of the loading capacity in these complex formulations (R2 0.79). The framework established here gives a better
understanding of drug solubility in single excipients and of LBF loading
capacity. The large data set studied revealed that experimental screening
efforts can be rationalized by solubility measurements in key excipients
or from solid state information. For the first time it was shown that
loading capacity in complex formulations can be accurately predicted
using molecular information extracted from calculated descriptors
and thermal properties of the crystalline drug.