Physicochemical Properties Services

Apredica offers a full range of physicochemical property determination services for small molecules, oligos, peptides, and industrial and consumer chemicals. Contact us to discuss appropriate applications.

PAMPA Permeability

• PAMPA: Measures the permeability of a test agent across an artificial membrane. Various buffers and pHs can be tested. This assay is used to predict oral bioavailability of test agents.
• BBB PAMPA: Predicts the permeability of a test agent across the blood-brain-barrier. High-throughput microtiter plate assay using porcine brain lipids in an artificial membrane.

Solubility

• Express solubility by UV/Vis turbidity: The solubility of your test agent in various buffers, cell culture media, or biological fluids will be determined. DMSO stock may be used. Critical for ensuring proper concentrations in biological assays.
• Solubility with HPLC determination: The exact solubility limit of your test agent in buffers and various biological fluids will be determined by HPLC or LC/MS/MS analysis. Saturating amounts of solid will be used. Assay can be miniaturized.

Chemical Stability

• Simulated gastric and intestinal fluid stability: Test agent is incubated in artificial gastric or intestinal fluids to simulate the fed or fasted states.
• Buffer stability: The stability of a test agent in various buffers can be tested.
• pH stability: The stability of a test agent across a pH range is measured.

Related In Vitro Models and Assays

• Metabolic stability assays
• Caco-2 and MDCK permeability assays
• EpiDerm, EpiAirway, other human epithelial permeability models
• Ask us about advanced BBB models

Customization

Customization of our physicochemical property assays is available. Common customization issues include:

• Alternative buffers
• Accommodation for a test agent that is a potential substrate for an efflux transporter
• Unusual test agents (e.g., oligos, peptides, industrial chemicals, etc.)

Please inquire about adaptations needed to address your needs.

Assay Purpose and Place

PAMPA Permeability

The Parallel Artificial Membrane Permeability Assay (PAMPA) assay we employ is an in vitro model of passive, transcellular permeability. PAMPA assays measures the diffusion of test agent across an artificial membrane after a defined period of time. Our PAMPA assay is highly customizable, supporting testing across a pH range and in alternative buffer conditions. The concentration of the test agent is measured on the donor and acceptor compartments using either HPLC, LC/MS/MS, or UV spectroscopy.

Our PAMPA assay is also offered in the Blood Brain Barrier (BBB) PAMPA format. In this format the composition of the lipid membrane includes brain-derived lipids, mimicking the BBB membrane.

Solubility

The solubility limits of your test agents may be determined in any medium you desire. Available formats are:

• Solubility by turbidity, with a UV/Vis readout.
• Determination of the actual concentration by HPLC or LC/MS/MS.

Chemical Stability

Depending on the chemical structure of your test agent it may be susceptible to instability in the stomach or intestine, or other biological buffers. Apredica offers a wide range of services in the area of chemical stability. Using our state-of-the-art analytical capabilities we can monitor the stability of test agents and formation of metabolites in any sort of media including but not limited to: simulated gastric and intestinal fluid, buffers, and pH ranges.

Contact us to learn more about Apredica's physicochemical property services.