Synthesis and Characterization of PEGylated Liposomes and Nanostructured Lipid Carriers with Entrapped Bioactive Triterpenoids: Comparative Fingerprints and Quantification by Uhplc-Qtof-Esi+-Ms, Atr-FTIR Spectroscopy and Hplc-Dad

Background/Objectives: Pentacyclic triterpenoids, as bioactive phytochemicals proved significant bioactivity (antioxidant, anti-inflammatory, hypoglycemic, and anticancer) and low cytotoxicity. This study developed convenient methods for extracting and characterizing a birch bark extract enriched in pentacyclic triterpenoids (betulin betulinic acid and lupeol) and entrapped in two bioavailable nanoformulations. The performance of ATR-FTIR spectroscopy as a cost-effective and non-destructive method was evaluated comparatively with accurate HPLC-based methods. Methods: The bark extract and pure betulin or betulinic acid were used to obtain PEGylated liposomes and Nano Lipid Carriers (NLC). Their size was characterized by light scattering diffraction. UV-VIS spectrometry was applied as a preliminary evaluation (1), the UHPLC-QTOF-ESI+-MS for structure identification (2), the ATR-FTIR spectroscopy (for semi-quantitative evaluation) (3), HPLC-DAD for accurate quantification of each component, either in the organic solvents and in nanoformulations (4). Results: The PEGylated liposomes had smaller sizes, and higher entrapment efficiency, significantly correlated between the three analytical methods. The performance of ATR-FTIR spectroscopy was positively correlated with HPLC-DAD data and confirmed the potential of this cheaper and reliable semi-quantitative method to evaluate the entrapment efficiency of TTs in liposome and NLC nanoformulations. Conclusions: The results recommend using liposomal nanoformulations for entrapment of bioactive terpenoids and their characterization by ATR-FTIR after validation by HPLC-DAD. The ATR-FTIR spectroscopy also offers the possibility of screening in a short time different recipes of nanoformulations as well as their stability and bioavailability, useful for investigations in vitro and in vivo which may confirm their efficacy as therapeutic agents.