Phase 3 clinical findings submitted on use of ALBUNEX for fallopian tube patency.

ST. LOUIS--(BUSINESS WIRE)--Sept. 16, 1996--Mallinckrodt Group Inc. (NYSE:MKG) in conjunction with Molecular Biosystems (NYSE:MB) has submitted to the U.S. Food and Drug Administration its findings from Phase 3 clinical trials of ALBUNEX (albumin (human), 5 percent, sonicated), ultrasound imaging agent, for use in infertility diagnosis in women.

The specific, unapproved use is for diagnosing fallopian tube patency, which refers to the extent to which the fallopian tube is open or obstructed.

The Phase 3 trial took place at 15 international sites in the United States, Sweden and France, and involved 433 women. ALBUNEX- enhanced ultrasound compared favorably to the two current clinical standards: hysterosalpinography (HSG), an X-ray-based procedure, and laparoscopy, a surgical procedure.

"We are encouraged by the results of the Phase 3 trials," said Neal L. Muhilly, imaging vice president-ultrasound for Mallinckrodt.

"A contrast-enhanced ultrasound procedure for diagnosing fallopian tube patency may offer several advantages to women. Unlike surgery, it would be minimally invasive. It is non-surgical. There would be no exposure to X-rays, and an ultrasound procedure can be performed in the privacy of a physician's office under the control of a physician."

Kenneth J. Widder, M.D., Molecular Biosystems' chairman and chief executive officer, said: "This submission for ALBUNEX marks the achievement of another milestone which the company said it would accomplish this year. Fallopian Tube Patency may be a specialty application for ALBUNEX and a continuation of our strategy in building a worldwide business in ultrasound imaging agents with our partner Mallinckrodt."

Mallinckrodt also recently entered an agreement with Conceptus Inc. to be the exclusive marketer and distributor of Conceptus Fallopian Tube Catheterization System in North, Central and South America. Under the agreement, Mallinckrodt will market and distribute Conceptus' Fallopian Tube Catheterization System to hospitals for the diagnosis of fallopian tube disorders.

"Mallinckrodt sees the minimally invasive diagnosis and treatment of fallopian tube disorders as an important and growing area of medicine, and we hope to provide products and services that will help both doctors and patients address these disorders more," Muhilly said.

ALBUNEX, a product of Molecular Biosystems Inc., is the first ultrasound contrast agent cleared by the U.S. Food and Drug Administration for use in the United States. Its current indication is for the diagnosis of cardiac disorders. It is marketed in the United States by Mallinckrodt.

Molecular Biosystems, based in San Diego, is a world leader in the development of ultrasound contrast agents for medical imaging. Its shares are listed on the New York Stock Exchange under the symbol "MB."

Mallinckrodt Group is a dynamic, international growth company serving specialty markets in human health care and chemicals and is dedicated to improving health care and chemistry.

Mallinckrodt is a major producer of analgesic pharmaceuticals, diagnostic imaging agents, medical devices, catalysts and laboratory and microelectronic chemicals. The St. Louis-based company, with fiscal 1996 net sales of $2.2 billion, sells more than 2,000 products in more than 100 countries. Mallinckrodt employs about 10,400 people worldwide.

This news release contains forward-looking statements that involve risk and uncertainties. The actual results of the trials described herein may differ from the company's expectations discussed. Among the factors that could result in a materially different outcome are the inherent uncertainties accompanying new product development.

CONTACT: Molecular Biosystems Inc., San Diego

Gerard A. Wills/Stephen F. Keane, 619/824-2248

or

Peter Faur, 314/854-5234 (media)

Barbara Abbett, 314/854-5230 (media)

Cole Lannum, 314/854-5370 (investors)