Assessment strategies for drug permeability during drug discovery and development / 药学学报

Permeability is a key factor in the bioavailability of oral drugs. Therefore, in the early stage of drug discovery, accurate and efficient evaluation of drug permeability is essential. The parallel artificial membrane permeability assay (PAMPA) with Caco-2 cells model was used by the industry as early evaluation methods. At present, the Ussing chamber rat model is also widely used. This review summarizes the human data for the in vivo single-pass perfusion technique (Loc-I-Gut) – the gold standard, and then focuses on the basic principles, experimental operation, and efficiency of the three in vitro methods, with correlation to the effective permeability coefficient (Peff) and fractional absorbed (Fa) in man. We provide recommendations for the use of proper permeability methods at different stages in drug discovery and development.

Advances in models for predicting drug intestinal permeability / 药学学报

Intestinal permeability is one of key factors determing absorption of oral drug products. It is a big challenge to assess permeability of compounds with high accuracy and high efficacy during research and development process. In this review, the principles, strengths, weaknesses and advances of common intestinal permeability models are summarized, with focus on Ussing chamber and parallel artificial membrane permeability assay. In addition, future trends of permeability models are briefly discussed. This review may provide a reference to accessing permeability of lead compounds.

Dissolution and Permeability Behavior of Diclofenac Sodiumenteric-Coated Tablets In-Vitro / 中国药学杂志

OBJECTIVE: To investigate the permeability of diclofenac sodium(DS)through parallel artificial membrane, and compare the differences in the dissolution rates and fluxes of diclofenac sodium enteric-coated tablets from Novartis in Beijing, Turkey and Germany.METHODS :The permeation of diclofenac sodium in different pH media was studied and determined.The effects of excipients on the permeability of diclofenac sodium were investigated by comparing the differences in the permeability of diclofenac sodium enteric-coated tablets.After being placed in acidic media of pH 6.0 and pH 6.8 for 2 h, the difference in the dissolution profiles and membrane fluxes of three sources diclofenac sodium enteric-coated tablets were determined and compared. RESULTS: The permeability of diclofenac sodium in pH 5.0-6.8 medium increased with the decrease of pH value, which was the smallest in pH 6.8 medium (1.08×10-4 cm•s-1). The excipients did not affect the permeability of the main component. The dissolution rate of the sample from Turkey Novartis was slightly faster than those from Beijing and Germany Novartis. CONCLUSION: The permeability of diclofenac sodium depends on the pH of the medium. The biopharmaceutics classification system(BCS) of diclofenac sodium is classified as class Ⅱ, a drug of low solubility and high permeability. The dissolution of diclofenac sodium enteric-coated tablets depends on the dissolving rate of the enteric-coating and the dissolution rate of the tablet core.The dissolution behaviors of diclofenac sodium enteric-coated tablets from different regions of the same company in pH 6.0 and pH 6.8 media are difference but the membrane fluxes are similar. This study may provide data support for the selection of multi-source reference preparations in the evaluation of generic drug conformance, and plays an important guiding role in prescription screening and bioequivalence risk assessment.