Abstracts Book - IMRC 2018

• SA6-O043
FUNCTIONAL NANOSTRUCTURED POROUS SILICON CARRIERS
FOR TYPE 2 DIABETES MELLITUS ORAL THERAPHY
Gabriela Sarahi García Briones 1 , Juan Jesus Barrios Capuchino 2 , María del Carmen González
Castillo 1 , Raul Ocampo Perez 1 , Alma Gabriela Palestino Escobedo 1
1
Universidad Autónoma de San Luis Potosí, Facultad de Ciencias Quimicas, Mexico.
2 Universidad Autónoma de San Luis Potosí, Facultad de Ciencias, Mexico.
Porous silicon (pSi) designed and synthesized through electrochemical etching
of crystalline silicon wafers, has been used in recent years as a versatile vehicle
for administration and release of drugs, having in mind the goal of finding an
alternative platform to solve intrinsic limitations associated with traditional
therapy, especially in oral administration. Several of its magnificent properties
like biodegradability and biocompatibility have made pSi an ideal candidate for
the design and development of functional biomaterials for biomedical
applications. Metformin, a biguanide type oral antihyperglycemic agent, is
currently the first-line antidiabetic drug not only to prevent and treat type 2
diabetes mellitus, but also pathologies closely related to this disorder such as
hypertension and obesity. However, despite all its benefits, high metformin
doses required by traditional administration lead several gastrointestinal
symptoms (nausea, vomiting, bloating, abdominal pain) which affect up to 30%
of patients and in some cases (5-10%) due total gastrointestinal intolerance,
treatment must be completely suspended. In this work, porous silicon (pSi)
nanostructured particles were designed as tunable carriers for sustained
delivery of metformin hydrochloride. Native pSi surface was chemically modified
by thermal oxidation to enhance drug physical adsorption/desorption.
Successfully conjugation of metformin onto pSi was assessed by a combination
of ATR FT-IR, nitrogen adsorption–desorption, zeta potential and TGA.
Adsorption and release kinetics were quantified by UV-Vis spectroscopy,
showing a metformin loading of ~470 mg MET/mg pSi and a sustained release
profile of about 60% of loaded drug along 24 h in pH 7.4. Adsorption behavior
was also thermally modeled to determine diffusion coefficients of metformin
from solutions with different concentrations (2, 4, 6, 8, 10 mg/ml MET) and
experimental data was compared with computations done by COMSOL
Multiphysics. From modelling, it was found out that mathematical model based
on pore volume diffusion was capable to predict decay curves as well as
adsorption metformin values. Synergistic effect between metformin and pSi
carrier was also demonstrated in vitro, by means of physiological evaluation and