title: Assessing the In Vitro Drug Release from Lipid-Core Nanocapsules: a New Strategy Combining Dialysis Sac and a Continuous-Flow System.
abstract: The in vitro assessment of drug release from polymeric nanocapsules suspensions is one of the most studied parameters in the development of drug-loaded nanoparticles. Nevertheless, official methods for the evaluation of drug release from submicrometric carriers are not available. In this work, a new approach to assess the in vitro drug release profile from drug-loaded lipid-core nanocapsules (LNC) was proposed. A continuous-flow system (open system) was designed to evaluate the in vitro drug release profiles from different LNC formulations containing prednisolone or clobetasol propionate (LNC-CP) as drug model (LNC-PD) using a homemade apparatus. The release medium was constantly renewed throughout the experiment. A dialysis bag containing 5 mL of formulation (0.5 mg mL(-1)) was maintained inside the apparatus, under magnetic stirring and controlled temperature (37°C). In parallel, studies based on the conventional dialysis sac technique (closed system) were performed. It was possible to discriminate the in vitro drug release profile of different formulations using the open system. The proposed strategy improved the sink condition, by constantly renewing the release medium, thus maintaining the drug concentration farther from the saturated concentration in the release medium. Moreover, problems due to sampling errors can be easily overcome using this semi-automated system, since the collection is done automatically without interference from the analyst. The system proposed in this paper brings important methodological and analytical advantages, becoming a promising prototype semi-automated apparatus for performing in vitro drug release studies from drug-loaded lipid-core nanocapsules and other related nanoparticle drug delivery systems.
authors.affiliation: Programa de Pós-Graduação em Ciências Farmacêuticas, Departamento de Produção e Controle de Medicamentos, Universidade Federal do Rio Grande do Sul, Avenida Ipiranga, 2952, Porto Alegre, RS, 90610-000, Brazil.
authors.forename: Diego Fontana
authors.initials: DF
authors.lastname: de Andrade
authors.affiliation: Programa de Pós-Graduação em Ciências Farmacêuticas, Departamento de Produção e Controle de Medicamentos, Universidade Federal do Rio Grande do Sul, Avenida Ipiranga, 2952, Porto Alegre, RS, 90610-000, Brazil.
authors.forename: Carine
authors.initials: C
authors.lastname: Zuglianello
authors.affiliation: Programa de Pós-Graduação em Ciências Farmacêuticas, Departamento de Produção e Controle de Medicamentos, Universidade Federal do Rio Grande do Sul, Avenida Ipiranga, 2952, Porto Alegre, RS, 90610-000, Brazil.|Departamento de Química Orgânica, Instituto de Química, Universidade Federal do Rio Grande do Sul, Avenida Bento Gonçalves, 9500, Porto Alegre, RS, 91501-970, Brazil.
authors.forename: Adriana Raffin
authors.initials: AR
authors.lastname: Pohlmann
authors.affiliation: Programa de Pós-Graduação em Ciências Farmacêuticas, Departamento de Produção e Controle de Medicamentos, Universidade Federal do Rio Grande do Sul, Avenida Ipiranga, 2952, Porto Alegre, RS, 90610-000, Brazil.
authors.forename: Silvia Stanisçuaski
authors.initials: SS
authors.lastname: Guterres
authors.affiliation: Programa de Pós-Graduação em Ciências Farmacêuticas, Departamento de Produção e Controle de Medicamentos, Universidade Federal do Rio Grande do Sul, Avenida Ipiranga, 2952, Porto Alegre, RS, 90610-000, Brazil. ruy.beck@ufrgs.br.
authors.forename: Ruy Carlos Ruver
authors.initials: RC
authors.lastname: Beck
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods; D002990:Clobetasol / Q000737:chemistry; D004337:Drug Carriers / Q000737:chemistry; D016503:Drug Delivery Systems / Q000379:methods; D065546:Drug Liberation; D008055:Lipids / Q000737:chemistry*; D053769:Nanocapsules / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D006435:Renal Dialysis / Q000295:instrumentation / Q000379:methods*
chemical_list: D004337:Drug Carriers; D008055:Lipids; D053769:Nanocapsules; D011108:Polymers; D002990:Clobetasol
keywords: dialysis sac technique; flow-through cell apparatus; in vitro drug release; lipid-core nanocapsules; sink condition