PharmaDiagnostics NV, a company developing and marketing a broadly-enabling, label-free screening technology that uniquely
does not require specialised instrumentation, was recently awarded with a European patent for its innovative SoPRano ADME assays
(absorption, distribution, metabolism, and excretion of drug compounds).

The European patent entitled 'reagents and methods for the determination of PK/ADME-Tox characteristics of new chemical entities and of drug candidates', was awarded by the European patent office and provides formal acknowledgement of, and protection for, SoPRano label-free SPR-based assays that can be used to assess the ADME properties of compounds earlier in the
drug discovery process.

“This patent is a clear recognition and acknowledgement of the innovative nature and commercial applicability of our SoPRano technology platform that enables improvements to the efficiency of the drug discovery process,” said Dr David Ricketts, CEO, PharmaDiagnostics.

He informed that the assays covered by this patent are already being trialled by a number of major pharmaceutical companies. As a result, the patent provides the company with  further business growth opportunities.

The SoPRano technology is unique in enabling label-free screening without a dedicated expensive instrument. For the first time, label-free assays can be applied in higher throughput earlier in drug discovery process to enable more informed decision making.
ADME assays currently marketed as SoPRano products and services include HSA and AGP interaction affinities, fraction unbound in plasma and volume of distribution, pKa, blood brain barrier permeability, bioavailability, and redox potential.


PharmaDiagnostics also launched three new methods for coupling proteins to the gold nanoparticles used with PharmaDiagnostics’ SoPRanoTM technology. The new coupling methods will
greatly expand the technology’s applicability in the key drug discovery and life science research markets.

The three new coupling methods, for use with SoPRano ‘build-your-own-assay’ kits are carboxyl coupling, one of the most commonly used techniques employed by SPR instrument users, providing a stable covalent linkage of protein to the
nanoparticles; Charge Adsorption 2 (CA2) methodology, which expands the current SoPRano charge adsorption method to proteins in high salt and with high pI and biotin-direct (BD), which uniquely enables direct coupling of biotinylated proteins to gold nanoparticles.

The method has a particular benefit over standard streptavidin-biotin couplings in that the biotinylated proteins bind directly to the gold, without the need for streptavidin. non-specific binding of potential drug candidates to streptavidin is a frequent problem that greatly complicates the discovery process, reducing success rates and increasing cost. PharmaDiagnostics’ biotin-direct method now offers pharma and biotech companies a method that overcomes these issues, with the potential to improve the quality of early stage drug discovery. Both the CA2 and BD methods are patent pending.

PharmaDiagnostics’ SoPRano technology is based on localised surface plasmon resonance (SPR), a variant of the well-proven SPR technology. Unlike standard SPR techniques, SoPRano uses gold nanoparticles in solution form and therefore is suitable to high throughput applications using only standard laboratory equipment, thereby eliminating the need for costly specialist or dedicated equipment. Coupling of target proteins to SoPRano nanoparticles is the first step in assay development, and the three new coupling methods extend the range of proteins that can be coupled to SoPRano nanoparticles, thereby enabling broader application of the technology in pharmaceutical research.

The current SoPRano coupling method, Charge Adsorption 1, introduced by PharmaDiagnostics in September 2010, is already being trialled by seven of the top ten pharma and multiple biotech companies.

“These three new coupling methods expand the range of proteins that can be coupled using SoPRano technology. They are also designed to parallel those coupling methods used on existing SPR instruments. This means PharmaDiagnostics’ SoPRano platform can be applied more routinely, accelerating its adoption at an increasing number of companies. These couplings also provide PharmaDiagnostics with a base for the further extension
of our product range, including new applications and additional coupling methods to be announced from April 2011,” said Dr David Ricketts, CEO PharmaDiagnostics.