In vitro release of diclofenac diethylamine from gels: evaluation of generic semisolid drug products in Brazil

Abstract

In order for the pharmacological action of a topical dermal drug product to occur, the drug must first be released from the vehicle to be available to penetrate the skin layers and reach the site of action. Drug release is mainly dependent on the characteristics of the formulation. Currently, to register a generic or a similar drug product in Brazil performance testing of topical drug products for local action is not required. In this context, this aim of this study was to evaluate the in vitro release of commercial diclofenac diethylamine gel products available on the Brazilian pharmaceutical market, using the vertical diffusion cell method. Factors which may influence the test, such as the type of membrane used, and the effect of the formulation characteristics on the diffusion rate were evaluated. Brazilian legislation currently allows generic drug products to contain excipients other than the reference drug, which may affect the drug release from the vehicle. Only one of the four generic drug products tested could be considered equivalent to the reference Cataflam Emulgel ® . The cellulose acetate and polyethersulfone membranes tested were found to be interchangeable in the in vitro release studies carried out on this product. Uniterms:In vitro release test. Diclofenac diethylamine/gel. Synthetic membranes. Generic semisolid drug products.Para exercer ação farmacológica, medicamentos tópicos de aplicação cutânea precisam, primeiramente, liberar o fármaco do veículo, para que desta forma ele se torne disponível para penetração nas camadas da pele, até atingir seu local de ação. A liberação do fármaco do veículo depende principalmente das características da formulação. Até a presente data, para registrar um medicamento genérico ou similar no Brasil não se exigem testes de desempenho para produtos tópicos de ação local. O presente trabalho teve como objetivo avaliar a liberação in vitro de especialidades farmacêuticas de diclofenaco dietilamônio gel do mercado farmacêutico brasileiro, usando o sistema de célula de difusão vertical. Avaliaram-se fatores que influenciam o teste como o tipo de membrana usada nos ensaios de liberação e características da formulação que impactam a velocidade de difusão. A legislação vigente no País permite que medicamentos genéricos contenham excipientes diferentes do medicamento referência. Esta diferença afetou a liberação do fármaco do veículo. Dos quatro medicamentos genéricos testados apenas um seria considerado equivalente ao medicamento referência Cataflam Emulgel ® . As membranas de acetato de celulose e polietersulfona testadas apresentaram-se intercambiáveis nos estudos de liberação desse produto.

The tetrapeptide N-acetyl-Pro-Pro-Tyr-Leu in skin care formulations—Physicochemical and release studies

“…In fact peptides can be found in a large number of cosmetics and cosmeceuticals (Zhang and Falla, 2009) including anti-aging, anti-wrinkle and skin moisturizing products, therefore it is important to analyze the formulations that contain these compounds. In order for the action of a dermal semisolid formulation to occur, the active compound must first be released from the vehicle in order to penetrate through the skin layers (Goebel et al, 2013). The release of active components is to a large extent dependent on the properties of the semisolid dosage form.…”

Compounded Topical Amitriptyline for Neuropathic Pain: In Vitro Release from Compounding Bases and Potential Correlation with Clinical Efficacy

“…In vitro drug release testing and the subsequent investigation of active ingredient permeation through the skin from semisolid preparations are essential in formulation development, quality control procedures, and prediction of in vivo performance of a product. 27 In addition to aiding in formulation development, in vitro drug release testing serves to compare the performance of different noncommercial compounded medications with various bases and excipients. 26 According to the USP, "The vertical diffusion cell (VDC) system is a simple, reliable, and reproducible means of measuring drug release from semisolid dosage forms".…”

Quality Analysis of Semisolid Formulations With Elderflower (Sambucus Nigra L.) Liquid Extract

“…According to the linearity of the obtained Higuchi curves (Fig. 5), it can be stated that the release of flavonoids from the semisolid formulations was influenced by the diffusion process of the compounds at the base (26,27).…”