Antioxidant Efficacy and "In Vivo" Safety of a Bentonite/Vitamin C Hybrid.

L-ascorbic acid (LAA), commonly known as vitamin C, is an excellent and recognized antioxidant molecule used in pharmaceutical and cosmetic formulations. Several strategies have been developed in order to preserve its chemical stability, connected with its antioxidant power, but there is little research regarding the employment of natural clays as LAA host. A safe bentonite (Bent)-which was verified by in vivo ophthalmic irritability and acute dermal toxicity assays-was used as carrier of LAA. The supramolecular complex between LAA and clay may constitute an excellent alternative, since the molecule integrity does not seem to be affected, at least from the point of view of its antioxidant capacity. The Bent/LAA hybrid was prepared and characterized through ultraviolet (UV) spectroscopy, X-ray diffraction (XRD), infrared (IR) spectroscopy, thermogravimetric analysis (TG/DTG) and zeta potential measurements. Photostability and antioxidant capacity tests were also performed. The LAA incorporation into Bent clay was demonstrated, as well as the drug stability due to the Bent photoprotective effect onto the LAA molecule. Moreover, the antioxidant capacity of the drug in the Bent/LAA composite was confirmed.

A simple way for targeted delivery of an antibiotic: In vitro evaluation of a nanoclay-based composite.

The sodium-modified form of fluorohectorite nanoclay (NaFh) is introduced as a potential drug carrier, demonstrating its ability for the controlled release of the broad-spectrum antibiotic Ciprofloxacin through in vitro tests. The new clay-drug composite is designed to target the local infections in the large intestine, where it delivers most of the incorporated drug thanks to its pH-sensitive behavior. The composite has been conceived to avoid the use of coating technology and to decrease the side-effects commonly associated to the burst-release of the ciprofloxacin at the stomach level. NaFh was obtained from lithium-fluorohectorite by ion exchange, and its lack of toxicity was demonstrated by in vivo studies. Ciprofloxacin hydrochloride (Cipro) was encapsulated into the clay at different values of the pH, drug initial concentration, temperature and time. Systematic studies by X-ray diffraction (XRD), infrared and visible spectrophotometry (FT-IR and UV-vis), and thermal analysis (TGA) indicated that the NaFh host exhibits a high encapsulation efficiency for Cipro, which reaches a 90% of the initial Cipro in solution at 65 oC, with initial concentration of drug in solution of 1.36 x 10-2 mol L-1 at acid pH. XRD revealed that a true intercalation of Cipro takes place between clay layers. TG showed an increased thermal stability of the drug when intercalated into the clay, as compared to the "free" Cipro. IR suggested a strong clay-Cipro interaction via ketone group, as well as the establishment of hydrogen bonds between the two materials. In vitro drug release tests revealed that NaFh is a potentially efficient carrier to deliver Cipro in the large intestine, where the release process is mediated by more than just one mechanism.

Evaluación citotóxica y genotóxica del adyuvante AFCo1 por el ensayo de morfología de la cabeza del espermatozoide en ratón NMRI / Cytotoxic and genotoxic evaluation of the adjuvant AFCo1 by the sperm head morphology assay in NMRI mice

Se realizó un estudio para evaluar el potencial citogenotóxico en células espermàticas de ratón, del adyuvante AFCo1 (Adyuvante Finlay Cocleato 1) obtenido a partir del proteoliposoma de Neisseria meningitidis serogrupo B. El AFCo1 y su diluente se administraron por vía intranasal en una dosis de 40 µL (1 mg/mL), mientras que los controles positivo (ciclofosfamida) y negativo (agua destilada estéril), se administraron por vía oral a razón de 40 mg y 1 mL/kg respectivamente. Se utilizaron ratones (NMRI) de 8-12 semanas de edad, con peso corporal entre 27-30 g, a los cuales se les aplicaron cinco dosis con un intervalo de 24 h durante los primeros cinco días del experimento. Se evaluó la toxicidad general (peso corporal) e indicadores testiculares de citotoxicidad testicular (concentración espermàtica) y genotoxicidad (morfología espermàtica). El AFCo1 y su diluente no provocaron toxicidad general, citotoxicidad, ni genotoxicidad. La ciclofosfamida sí produjo citotoxicidad (47,77 por ciento) y genotoxicidad (534,61 por ciento). Se concluye que el AFCo1 y su diluente pueden ser considerados como no tóxicos para las células espermàticas en el nivel de dosis y para el biomodelo animal utilizado(AU)

This study was developed to evaluate the cytogenotoxic potential on mice spermatic cells of the candidate adjuvant, AFCol (Adjuvant Finlay Cochleate 1 Adjuvant); obtained from the proteoliposome of Neisseria meningitidis serogroup B. The AFCo1 and its diluent were administered via intranasal in a 40 µL dose (1 mg/mL), while the positive control (ciclofosfamide) and the negative one (sterile distilled water) were administered orally in 40 mg and 1 mL/kg respectively. Rats (NMRI) were from 8 to 12 week of age with weighing from 27 to 30 g and they were administered 5 doses with an interval of 24 hours during the first 5 days of the experiment. General toxicity (body weight), cytotoxicity of testicles (spermatic concentration) and genotoxicity (spermatic morphology) were evaluated. AFCol and its diluent provided neither general toxicity, cytotoxicity, nor genotoxicity. The cyclophosphamide produced cytotoxicity (47.77 percent) and genotoxicity (534.61 percent). It is concluded that AFCol and its diluent, could be considered non toxic for the spermatic cells with the dose level and the animal biomodel used(AU)