Naproxen Dissolution - Permeation

Naproxen tablets dissolution (Nalgesin 550 mg) release profiles and permeation (expressed as apparent permeability coefficient, Papp) across different membrane compositions. With aim to test novel dissolution-permeation setup and apply it to dissolution-permeation studies of poorly soluble drugs.
The dissolution-permeation system setup consisted of a compendial USP2 dissolution apparatus (Double ATSXstend, Sotax, Switzerland), a 6-channel peristaltic pump (LabN1-II/AMC6, Shenchen, China) with silicone tubing, and a CHM1 Ussing chamber with a 1.13 cm2 membrane opening (World Precision Instruments, USA). Two USP2 vessels were used simultaneously one vessel donor compartment, another acceptor compartment. The Ussing chamber was mounted to an in-house built stand and secured with screws. Silicone tubing (FedroTek, China) Ø2 mm, wall thickness 1 mm was connected to the Ussing chamber ensuring a leak-free system. The media pumping flow rate was 6 mL/min.
The dissolution study was performed using the pharmacopoeial PBS (1000 mL, pH 6.8, KH2PO4, NaOH). Water bath temperature was set at 37 ºC with a paddle rotation speed of 50 RPM. Off-line sampling and spectrophotometric quantification was performed over 120 minutes.
Dissolution-permeation study. Nalgesin 550 mg tablets were dissolved in 1000 mL pH 6.8 PBS in the donor vessel. The acceptor vessel contained 1000 mL pH 7.4 PBS (KH2PO4, NaOH). A permeable membrane filter was mounted in the Ussing chamber and covered with soy L-α-phosphatidylcholine solution in dodecane. Permeated naproxen in the acceptor media was UV-quantified on-line with sampling every 15 minutes, up to 180 minutes.
The Papp were calculated from the values on the linear part of the permeation curve.