Hydrogel containing dexamethasone-loaded nanocapsules for cutaneous administration: preparation, characterization, and in vitro drug release study.

Programa de Pós-Graduação em Ciências Farmacêuticas, Departamento de Farmácia Industrial, Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.
Drug Development and Industrial Pharmacy (Impact Factor: 1.54). 08/2010; 36(8):962-71. DOI: 10.3109/03639041003598960
Source: PubMed

ABSTRACT Our group previously reported the development of dexamethasone-loaded polymeric nanocapsules as an alternative for topical dermatological treatments.
Our study aimed to prepare and characterize a hydrogel containing this system to improve the effectiveness of the glucocorticoid for cutaneous disorders.
For the antiproliferative activity assay, a dexamethasone solution and D-NC were tested on Allium cepa root meristem model. D-NC were prepared by the interfacial deposition of preformed polymer. Hydrogels were prepared using Carbopol Ultrez 10 NF, as polymer, and characterized according to the following characteristics: pH, drug content, spreadability, viscosity, and in vitro drug release. Results and
Nanocapsules showed mean particle size and zeta potential of 201 +/- 6 and -5.73 +/- 0.42 nm, respectively. They demonstrated a lower mitotic index (4.62%) compared to free dexamethasone (8.60%). Semisolid formulations presented acidic pH values and adequate drug content (between 5.4% and 6.1% and 100% and 105%, respectively). The presence of nanocapsules in hydrogels led to a decrease in their spreadability factor. Intact nanoparticles were demonstrated by TEM as well as by dynamic light scattering (mean particle size < 300 nm). In vitro studies showed a controlled dexamethasone release from hydrogels containing the drug associated to the nanocapsules following the Higuchi's squared root model (k = 20.21 +/- 2.96 mg/cm(2)/h(1/2)) compared to the hydrogels containing the free drug (k = 26.65 +/- 2.09 mg/cm(2)/h(1/2)).
Taking all these results together, the hydrogel containing D-NC represent a promising approach to treat antiproliferative-related dermatological disorders.

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