Pharmacokinetic study of AmB-NP-GR: A new granule form with amphotericin B to treat leishmaniasis and fungal infections.

Amphotericin B (AmB) has been the gold standard to treat systemic fungal infections. The use of AmB is restricted to hospitals because it poses several risks, mainly risks related to its high nephrotoxicity. Given the importance of this drug in medicine, new therapeutics and AmB formulations with nanotechnological improvements are required and could bring many benefits to patients. A new drug formulation with gastro-resistant coated granules has been proposed. The lipid-based system containing AmB was produced and used as raw material in the granulation/coated process. The new developed formulation (AmB-NP-GR) was characterized by optical microscopy, granulometry, and atomic force microscopy (AFM) after disintegration test. AmB-NP-GR showed granular shape, with most granules measured between 250 and 500 µm (37 ± 7% w/w). The AFM images indicated that the granule formulation should disintegrate in the intestine, to release the lipid-based carriers, making them available for absorption and allowing them to reach the blood circulation. The developed formulation was administered to rats in a single dose of 4.0 or 8.0 mg kg-1 and the pharmacokinetics was studied. The samples were analyzed by liquid chromatography coupled to mass spectrometry. Before the pharmacokinetic studies were conducted, the bioanalytical method was validated according to the EMA guideline and all evaluated parameters agreed with this guideline. The pharmacokinetic results showed that Cmax was similar for both doses and that tmax was reached at 4-12 h for dose of 4.0 mg kg-1 and 4 h for dose of 8.0 mg kg-1. The half-life related to the dose of 8.0 mg kg-1 increased significantly compared to the dose of 4.0 mg kg-1 (an increase of more than 3 times). In addition, the mean residence time related to the dose of 8.0 mg kg-1 was 4 times higher than for the lower dose. The clearance value showed to be higher for the lower dose. Together, these results provide important conclusions for experimental design of other in vivo safety and efficacy studies of AmB-NP-GR.

Anti-Melanoma Activity of Indomethacin Incorporated into Mesoporous Silica Nanoparticles.

Melanoma is the deadliest type of skin cancer. Treatments that directly address tumor survival are required. Indomethacin (IND) is a well-known drug used worldwide. Although widely used as a therapeutic agent, IND has undesirable gastrointestinal effects. PURPOSE: To investigate the antitumor efficacy of IND incorporated into mesoporous silica nanoparticles (MSNPs+IND), as well as its toxic potential in a syngeneic murine B16 melanoma model. METHODS: Antitumor activity was evaluated by measuring tumor size and weight and by histopathological analysis. Possible molecular signaling pathways involved in the antitumor activity were analyzed by Western blot in liver tissue and by immunohistochemistry in tumor tissue. The potential toxicity was evaluated by determining body and organ weights and by biochemical and genotoxic analysis. RESULTS: MSNPs+IND treatments inhibited tumor growth by up to 70.09% and decreased the frequency of mitosis in tumor tissues, which was up to 37.95% lower compared to the IND groups. In hepatic tissue, COX-2 levels decreased significantly after treatment with MSNPs+IND and IND. Additionally, MSNPs+IND and IND increased the levels of cleaved caspase-3 (156.25% and 137.50%, respectively), inducing tumor cell apoptosis. Genotoxicity was limited to the group treated with the higher concentration of IND, while MSNPs prevented IND-induced genotoxicity. CONCLUSIONS: MSNPs may be promising for future applications in cancer therapy.