Background: Morin flavonoid exerts neuroprotective effects with potential interest in
neurodegenerative disorders. For this, the use of surface-modified polymeric nanoparticles loaded
with morin is an interesting approach.
Objective: To develop and validate an HPLC method for the quantification of morin released from
a new delivery system consisting of poly lactic-co-glycolic (PLGA) nanoparticles functionalized
with the dipeptide phe-phe (phenylalanine-phenylalanine) used to facilitate their access to the
Methods: The HPLC procedure was developed and validated with morin hydrate dissolved either
in methanol (method A) or in methanol: 0.1N HCl (50:50, v/v, method B). Two new nanoparticle
formulations were developed and characterized: morin-loaded PLGA nanoparticles (formulation
F1), and morin-loaded PLGA phe-phe nanoparticles (formulation F2).
Results: Method A was linear within the concentration range of 5-30 μg.mL-1 and, 1-30 μg mL-1
for method B. LOD and LOQ with method A were 1.23 μg.mL-1 and 3.90 μg.mL-1, respectively,
and 0.481 μg.mL-1 and 1.458 μg.mL-1, respectively for method B. The average amount of phe-phe
bound to formulation F2 (50 mg of NPs) was 431.33 μg. The encapsulation efficiency of morin
within PLGA nanoparticles was around 80%. After functionalization, this value decreased significantly.
Conclusion: Method B showed better sensitivity, accuracy, and precision for the quantification of
morin. The procedure used to functionalize the nanoparticles was adequate for linking the dipeptide
to their surfaces, but this procedure is not adequate when encapsulating water-soluble compounds.