Combining orthogonal measurements to unveil diclofenac encapsulation into polymeric and lipid nanocarriers

• Type: Article in International Scientific Journal
• Date: 2023

Authors

Marques, SS (Author) Other; Cant, DJH (Author) Other; Minelli, C (Author) Other; Marcela A Segundo (Author) FFUP

Journal

Title: Analytica Chimica Acta

Vol. 1262

ISSN: 0003-2670

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 0 Citations

Scopus

Other information

Authenticus ID: P-00Y-AJZ

DOI: 10.1016/j.aca.2023.341234

Abstract (EN): The quantification of the drug associated to nanoparticle carriers, often expressed in terms of encapsulation efficiency, is a regulatory requirement. The establishment of independent methods to evaluate this parameter provides a means for measurement validation, which is critical in providing confidence in the methods and enabling the robust characterization of nanomedicines. Chromatography is traditionally used to measure drug encapsulation into nanoparticles. Here, we describe an additional independent strategy based on analytical centrifugation. The encapsulation of diclofenac into nanocarriers was quantified based on the mass difference between placebo (i.e. unloaded) and loaded nanoparticles. This difference was estimated using particle densities measured by differential centrifugal sedimentation (DCS) and size and concentration values measured by particle tracking analysis (PTA). The proposed strategy was applied to two types of formulations, namely poly(lactic-coglycolic acid) (PLGA) nanoparticles and nanostructured lipid carriers, which were analysed by DCS operated in sedimentation and flotation modes, respectively. The results were compared to those from high performance liquid chromatography (HPLC) measurements. Additionally, X-ray photoelectron spectroscopy analysis was used to elucidate the surface chemical composition of the placebo and loaded nanoparticles. The proposed approach enables the monitoring of batch-to-batch consistency and the quantification of diclofenac association to PLGA nanoparticles from 0.7 ng to 5 ng of drug per 1 mu g of PLGA, with good linear correlation between DCS and HPLC results (R2 = 0.975). Using the same approach, similar quantification in lipid nanocarriers was possible for a loading of diclofenac >= 1.1 ng per 1 mu g of lipids, with results in agreement with the HPLC method (R2 = 0.971). Hence, the strategy proposed here expands the analytical tools available for evaluating nanoparticles encapsulation efficiency, being thus significant for increasing the robustness of drug-delivery nanocarriers characterization.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10