Generex Biotechnology Corp. said it terminated a letter of intent to buy a controlling interest in privately held Core-Tech Solutions Inc.

The U.S.-based maker of drug delivery systems had signed a letter of intent in August to acquire a 51% interest in Core-Tech Solutions for $15 million.

Core-Tech Solutions is a contract-based maker of transdermal patches that are placed on the skin to deliver medication into the bloodstream.

Generex Biotechnology said two pharmaceutical companies, which had commercialization contracts with Core-Tech, will not proceed with three contract development programs in the Core-Tech pipeline due to the re-evaluation of their priorities.

The new development, which came up during a due diligence, modified cash-flow projections and the requisite cash support needed from Generex for product development of the Core-Tech pipeline.

This led Generex to re-examine Core-Tech's valuation, with both parties discussing a restructuring of the letter of intent before agreeing to shelve the talks.

While Core-Tech confirmed formal termination of the letter of intent Dec. 8, the companies may revisit the deal later.