FePO4 NPs are of special interest in food fortification and biomedical imaging because of their biocompatibility, high bioavailability, magnetic property, and superior sensory performance that do not cause adverse organoleptic effects. These characteristics are desirable in drug delivery as well. Here, we explored the FePO4 nanoparticles as a delivery vehicle for the anticancer drug, doxorubicin, with an optimum drug loading of 26.81% ± 1.0%. This loading further enforces the formation of Fe3+ doxorubicin complex resulting in the formation of FePO4-DOX nanoparticles. FePO4-DOX nanoparticles showed a good size homogeneity and concentration-dependent biocompatibility, with over 70% biocompatibility up to 80 µg/mL concentration. Importantly, cytotoxicity analysis showed that Fe3+ complexation with DOX in FePO4-DOX NPs enhanced the cytotoxicity by around 10 times than free DOX and improved the selectivity toward cancer cells. Furthermore, FePO4 NPs temperature-stabilize RNA and support mRNA translation activity showing promises for RNA stabilizing agents. The results show the biocompatibility of iron-based inorganic nanoparticles, their drug and RNA loading, stabilization, and delivery activity with potential ramifications for food fortification and drug/RNA delivery.

OBJECTIVES To characterize the pharmacokinetics of a single oral dose (6 mg/kg) of mavacoxib in New Zealand White rabbits (Oryctolagus cuniculus) and to characterize any clinicopathologic effects with this medication and dose. ANIMALS Six healthy, 4-month-old New Zealand White rabbits (3 male, 3 female). PROCEDURES Before drug administration, clinicopathologic samples were collected for baseline data (CBC, serum biochemical analyses, and urinalysis including urine protein-to-creatinine ratio). All 6 rabbits received a single oral dose (6 mg/kg) of mavacoxib. Clinicopathologic samples were collected at set time intervals to compare with the baseline. Plasma mavacoxib concentrations were determined using liquid chromatography with mass spectrometry, and pharmacokinetic analysis was performed using non-compartmental methods. RESULTS After a single oral dose, the maximum plasma concentration (Cmax; mean, range) was 854 (713–1040) ng/mL, the time to Cmax (tmax) was 0.36 (0.17–0.50) days, the area under the curve from 0 to the last measured time point (AUC0-last) was 2000 (1765–2307) days*ng/mL, the terminal half-life (t1/2) was 1.63 (1.30–2.26) days, and the terminal rate constant (λz) was 0.42 (0.31–0.53) days. All results for CBCs, serum biochemical analyses, urinalyses, and urine protein-to-creatinine ratios remained within published normal reference intervals. CLINICAL RELEVANCE This study determined that plasma concentrations reached target levels of 400 ng/mL for 48 hours in 3/6 rabbits at 6 mg/kg PO. In the remaining 3/6 rabbits, the plasma concentrations were 343–389 ng/mL at 48 hours, which is below the target concentration. Further research is needed to make a dosing recommendation, including a pharmacodynamic study and investigating pharmacokinetics at different doses and multiple doses.