Parallel Artificial Membrane Permeability Assay (PAMPA)

As an in vitro model of passive transcellular permeation, the parallel artificial membrane permeability assay (PAMPA) is a low-cost, high-throughput method for analyzing the permeability of compounds and is widely used in drug development. PAMPA consists of simple reagents and lipids that mimic biological membranes and is used to determine the permeability of test compounds from the donor compartment into the acceptor compartment through lipid-infused artificial membranes. BOC Sciences' PAMPA assay simulates drug absorption in the gut to accurately predict the in vivo oral absorption efficiency of your compound. By working with a variety of clients, we can perfectly meet your project requirements and budget.

Why PAMPA?

The PAMPA permeability assay is a method that can be used to measure the permeability of drugs through (or retention) the concentrated negatively charged phospholipid bilayer barriers. PAMPA can quickly provide information about passive transport of drugs (only limited to passive transport, excluding paracellular transport, active transport, metabolism, etc.), and is an excellent cell model substitute that can be used for early screening of drugs. Presently, the PAMPA technology has been proven to have high data reliability for the permeability study of drugs.

Fig. 1 Schematic diagram of PAMPA

Compared to other traditional permeability monitoring methods such as Caco-2 and MDCK monolayers, PAMPA is inexpensive and does not require extensive cell culture time. The results obtained from PAMPA analysis are usually effective permeability values (Pe), which can be used to estimate the potential of new compounds to cross biological barriers such as the gastrointestinal tract or the blood-brain barrier. The PAMPA method uses a filter membrane to divide the 96-well plate and the 96-well filter plate into two chambers (donor chamber and acceptor chamber). The buffer (Ph 5.0-pH 7.4) was added to the donor chamber and the blank buffer (pH 7.4) was added to the receptor chamber. As shown in Fig 1, after incubation at 37°C for a period of time, the drug concentration on the receptor compartment side was determined using UV spectrophotometry.

Analysis Design

• Test articles run in triplicate
• One concentration (10 µM)
• One point in time (4 hours)
• One pH (7.4) or three-point pH range (5.0, 6.2, 7.4) of the receptor compartment
• Monopolar membrane lipid (phosphatidylcholine in dodecane)
• Multi-screen PVDF membrane (0.45 µm)
• Positive control: propranolol (high permeability)
• Negative control: atenolol (low permeability)

Analysis: Concentration of compound remaining in the donor well, diffusing through the membrane and entering the acceptor well, and measuring the concentration of the reference compound by UV spectrophotometry.

Reporting: Classify results as high, medium or low predicted absorption and report direct permeability units (10-6 cm/s).

Quantity of test article required: 5.0 - 7.0 mg.

As a leading supplier of ADME, BOC Sciences can utilize the PAMPA model to assess the effect of passive diffusion on drug absorption and the effect of pH on permeability. In addition, we can also compare the oral absorption efficiency of various pharmaceutical preparations and provide absorption kinetic parameter determination services. If you are interested in our PAMPA assay, please contact us for more information.