title: Hydrogel containing dexamethasone-loaded nanocapsules for cutaneous administration: preparation, characterization, and in vitro drug release study.
abstract: BACKGROUND
  Our group previously reported the development of dexamethasone-loaded polymeric nanocapsules as an alternative for topical dermatological treatments.
  
  
  OBJECTIVE
  Our study aimed to prepare and characterize a hydrogel containing this system to improve the effectiveness of the glucocorticoid for cutaneous disorders.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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)).
  
  
  CONCLUSIONS
  Taking all these results together, the hydrogel containing D-NC represent a promising approach to treat antiproliferative-related dermatological disorders.
authors.affiliation: 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.
authors.forename: M L
authors.initials: ML
authors.lastname: Marchiori
authors.forename: G
authors.initials: G
authors.lastname: Lubini
authors.forename: G
authors.initials: G
authors.lastname: Dalla Nora
authors.forename: R B
authors.initials: RB
authors.lastname: Friedrich
authors.forename: M C
authors.initials: MC
authors.lastname: Fontana
authors.forename: A F
authors.initials: AF
authors.lastname: Ourique
authors.forename: M O
authors.initials: MO
authors.lastname: Bastos
authors.forename: L A
authors.initials: LA
authors.lastname: Rigo
authors.forename: C B
authors.initials: CB
authors.lastname: Silva
authors.forename: S B
authors.initials: SB
authors.lastname: Tedesco
authors.forename: R C R
authors.initials: RC
authors.lastname: Beck
mesh_terms: D000279:Administration, Cutaneous; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D055598:Chemical Phenomena; D003907:Dexamethasone / Q000008:administration & dosage* / Q000032:analysis / Q000737:chemistry* / Q000494:pharmacology; D004058:Diffusion; D004337:Drug Carriers / Q000008:administration & dosage* / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology; D004339:Drug Compounding / Q000379:methods; D020100:Hydrogels / Q000138:chemical synthesis* / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology; D018519:Meristem / Q000166:cytology / Q000187:drug effects; D008938:Mitosis / Q000187:drug effects; D053769:Nanocapsules / Q000008:administration & dosage* / Q000737:chemistry*; D019697:Onions / Q000187:drug effects; D010316:Particle Size; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects; D012995:Solubility; D013535:Suspensions
chemical_list: D000893:Anti-Inflammatory Agents; D004337:Drug Carriers; D020100:Hydrogels; D007166:Immunosuppressive Agents; D053769:Nanocapsules; D013535:Suspensions; D003907:Dexamethasone