Combination of Doxorubicin and Antiangiogenic Agents in Drug-Eluting Beads: In Vitro Loading and Release Dynamics in View of a Novel Therapeutic Approach for Hepatocellular Carcinoma

PURPOSE

Antiangiogenic agents have been used for many years as a first-line systemic treatment for advanced HCC. Embolization with cytostatic drugs on the other hand is the first-line treatment for intermediate HCC. The two types of drugs have not been combined for intraarterial delivery yet. The loading and release dynamics and the in vitro effect of their combination are tested in this experimental study.

MATERIALS AND METHODS

Drug-eluting beads were loaded with doxorubicin, sunitinib and sunitinib analogue piperazine (SAP) alone and with their combinations. Diameter change, loading, release, and effect in cellular proliferation were assessed.

RESULTS

The average microsphere diameter after loading was 473.7 µm (μm) for Doxorubicin, 388.4 μm for Sunitinib, 515.5 μm for SAP, 414.8 μm for the combination Doxorubicin/Sunitinib and 468.8 μm for the combination Doxorubicin /SAP. Drug release in 0.9% NaCl was 10% for Doxorubicin, 49% for Sunitinib, 25% for SAP, 20%/18% for the combination Doxorubicin/Sunitinib, and 18%/23% for the combination Doxorubicin/SAP whereas in human plasma it was 56%, 27%, 13%, 76%/63% and 62%/15%, respectively. The mean concentration of Doxorubicin that led to inhibition of 50% of cellular proliferation in an HCC Huh7 cell line was 163.1 nM (nM), for Sunitinib 10.3 micromolar (μΜ), for SAP 16.7 μΜ, for Doxorubicin/Sunitinib 222.4 nM and for Doxorubicin/SAP 275 nM.

CONCLUSIONS

Doxorubicin may be combined with antiangiogenic drugs with satisfactory in vitro loading and release outcomes and effect on cellular lines.

New insights in the in vitro release of phenolic antioxidants: The case study of the release behavior of tyrosol from tyrosol-loaded ethylcellulose microparticles during the in vitro gastrointestinal digestion

In this study, tyrosol - a phenolic antioxidant that present in olive oil and olive mill wastes - was embedded in ethylcellulose microparticles by double emulsion solvent evaporation technique. The effect of loading content (5 % w/w and 10 % w/w) on the release behavior and bioaccessibility of tyrosol was evaluated. The polymer endowed efficient protection to tyrosol during the in vitro gastrointestinal digestion of loaded microparticles as the maximum release of tyrosol was observed during the simulated intestinal digestion, and the releases were kept outstanding low during the simulated salivary and gastric digestions. The bioaccessibility of tyrosol was improved when encapsulated. The best-fitting models of the release profiles of tyrosol were the first, and the zero-order models for formulations considering a loading of 5% w/w and 10 % w/w, respectively. The results of this study bring new perspectives for the design of loaded microparticles that will be further submitted to gastrointestinal digestion.