ROCKVILLE, MD – (28 April, 2000) – Shire Laboratories Inc., a subsidiary of Shire Pharmaceuticals Group plc ("Shire") (LSE: SHP.L, NASDAQ: SHPGY), today announced that the U.S. Patent and Trademark Office has issued a Notice of Allowance for the company's patent application related to its novel osmotic drug delivery technology, EnSoTrol®. The invention covers the delivery of poorly water soluble drugs in an extended controlled-release oral osmotic dosage form that contains the drug, as well as non-swelling solubilizing, osmotic, and wicking agents. The wicking agent enhances the surface area contact of the drug with the fluid drawn into the tablet from the gastrointestinal tract. The drug is partially solubilized by the incoming fluids and is delivered through one, or more laser-drilled holes in the tablet coating, leading to an extended, consistent delivery.

   "This represents a major milestone for Shire Laboratories. Shire is now the only drug delivery company that has patented and proven technologies in all three areas of oral controlled-release drug delivery: multiparticulate, matrix and osmotic systems." said Jack A. Khattar, President and CEO. "We are pleased with the progress we have made in establishing Shire as a leader in the drug delivery industry with a strong portfolio of advanced technologies."

   Shire Laboratories has several technologies in the controlled release area. In addition to EnSoTrol®, there is Microtrol™ XR, Microtrol™ PR, Microtrol™ DR, and Solutrol®. Microtrol™ represents a family of multiparticulate drug delivery technologies, based on the use of beadlets that can be filled into capsules or compressed into tablets. Solutrol® is a matrix tablet that is designed to provide an extended-release drug delivery profile mainly for highly soluble compounds. Also, the company has OptiScreen™, a family of advanced high throughput screening technologies designed to study molecules and improve their oral bioavailability through enhanced solubility and permeability.

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   THE "SAFE HARBOR" STATEMENT UNDER THE PRIVATE SECURITIES LITIGATION REFORM ACT OF 1995. The statements in this press release that are not historical facts are forward-looking statements that involve risks and uncertainties, including but not limited to, risks associated with the inherent uncertainty of pharmaceutical research, product development and commercialization, the impact of competitive products, patents, and other risks and uncertainties, including those detailed from time to time in periodic reports, including the F-4 Prospectus and the Annual Report filed on Form 20-F with the Securities and Exchange Commission.