Development and characterization of mucoadesive nanoparticles based on hyaluronic acid for methotrexate colonic release

Author(s)

Fernanda Isadora Boni

• Document type: Master's Dissertation
• Press: Araraquara. 2018-01-05.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Farmacêuticas. Araraquara
• Defense date: 2017-09-29
• Advisor: Maria Palmira Daflon Gremião

Abstract

The pharmaceutical nanotechnology is a relevant technological tool for the development of new drug delivery systems, because of their small size they are able to circulate through capillaries that irrigate tissues, escape from phagocytosis by the immune system cells and passively permeate cells and epithelia. In addition, these systems enable the encapsulation of low stability drugs, protecting them against premature degradation and/or allowing the modulation of their physico-chemical properties, as well as the biological interaction in the biointerface. Methotrexate (MTX) is one of the most used drug in the treatment of solid tumors and inflammatory bowel diseases, however, because MTX highly cytotoxic and nonselectivity promotes several side effects. Its therapeutic efficacy is compromised due to the resistance acquired by tumor cells and it low intestinal permeability, mainly through the efflux mechanism of the free form. In this work, oral nanoparticles composed of chitosan (CS), hyaluronic acid (HA) and hydroxypropylmethylcellulose (HP) phthalate, polymers that have properties such as pH-dependent solubility, mucoadhesiveness and functionalization have been developed as a technological platform for the target of MTX to the colon, aiming the treatment of local pathologies. Molecular weight and second viral coefficient analyzes demonstrated the suitability of polymers and solvents to obtain nanostructures by the polyelectrolyte complexation method. The evaluation of the pH influence on the zeta potential of the polymers allowed to the selection of the optimum value (pH 5.5) to obtain the nanostructures. The mean diameter of the MTX free nanoparticles, containing or not HP ranged from 451.73-574.95 nm and the incorporation of MTX significantly reduced these values for the range of 216.83-345.03 nm (p <0.05). The addition of HP as well as MTX promoted reduction of zeta potential of nanoparticles (p <0.05). The polydispersity index of the nanoparticles containing or not MTX ranged from 0.21-0.39 to 0.26-0.33, respectively, indicating homogeneity of size. The spherical shape of the particles has been demonstrated. The absorption spectra in the IV region indicated the formation of the polyelectrolyte complexes and the DRX analyzes, the formation of crystalline structures. The efficiency of drug incorporation ranged from 20.06% to 36.18%, with the NHP0.5-1 and NHP0.2-5 samples having the highest percentages (32.21% and 36.18%, respectively). Although MTX promoted the reduction of mucoadhesion values (p<0.05), the high mucoadhesiveness (71.22% to 91.53%) of all nanoparticles was evidenced. According to the adsorption isotherms, the interaction data with the mucin presented a correlation with the Freundlich model, which indicates the reversible adsorption in multilayers. At pH 6.8, the interaction of mucin with the nanoparticles promoted the reduction of the zeta potential, which may be related to the higher adsorption capacity at this pH value. The incorporation of MTX in the nanoparticles allowed to the reduction of MTX release in acidic media by up to 40% in relation to the free drug and the addition of HP to the nanoparticle matrix reduced the release by up to 10% at pH 1.2. The mechanism of drug release was evaluated by different mathematical models. The viability of Caco-2 and HT29-MTX lines for polymers and NPs (0.01-1 μg.mL-1) was demonstrated. For nanoparticles containing MTX, at concentrations of 10 μg.mL-1 and 100 μg.mL-1 , the viability of Caco-2 after 24 h incubation was approximately 50%. In the in vitro permeability studies, samples without HP permeated approximately 3- fold more monolayers of Caco-2 and triple co-culture compared to samples containing HP and the free drug. The higher cellular association for the drug incorporated into the nanoparticles, compared to free MTX, demonstrated the ability of the system to modulate the biological interaction (AU)

• FAPESP's process: 15/21176-5 - Development and characterization of mucoadhesive nanoparticles based on hyaluronic acid for colon specific release of methotrexate
• Grantee: Fernanda Isadora Boni
• Support Opportunities: Scholarships in Brazil - Master