Validated QuEChERS-HPLC-UV Method for Quantification of Cannabidiol in Pharmaceutical Nanoformulations

Cannabidiol (CBD) nanoformulations have gained increasing interest in pharmaceutical development. However, comprehensive analytical methods for complex nanoformulated samples remain underexplored. In this study, an HPLC-UV method coupled with QuEChERS extraction was developed and validated according to ICH guidelines for nanoformulated CBD analysis. Representative matrices included spray-dried CBD-loaded lipid nanoparticle (CBD-LNP) powder and Dulbecco's modified Eagle medium (DMEM) for cell-based assays. The method showed excellent linearity (R² > 0.999) over 1-100 µg/mL for both matrices, with minimal matrix effects. The LODs were 0.17 and 0.15 µg/mL, and the LOQs were 0.51 and 0.46 µg/mL for powder and DMEM, respectively. CBD recoveries were above 90% for both powder and DMEM. Intra- and inter-day precision (%RSD) were below 2.8% and 7.8%, respectively. The validated method was applied to stability testing of nanoformulated CBD products containing 3% and 5% CBD, showing that 25 °C was the optimal storage temperature over 6 months. A cellular uptake study also revealed higher uptake of the nanoformulated CBD than the isolate and oil-based forms. Overall, this workflow provides a reliable and accessible approach for nanoformulated CBD analysis, supporting nanopharmaceutical research and routine quality control.