NEW CHRONOSPHERE® FORMULATION OFFERS SIGNIFICANT ADVANTAGES FOR PEOPLE WITH EPILEPSY

NEW CHRONOSPHERE® FORMULATION OFFERS SIGNIFICANT ADVANTAGES FOR PEOPLE WITH EPILEPSY Vienna June 1, 2004 - Sanofi-Synthelabo announced today the introduction of Chronosphere®, a new innovative dosage form of the leading antiepileptic agent sodium valproate, marketed worldwide under the brand names Depakine®, Epilim®, Ergenyl® and Deprakine®. This high-tech, sustained-release formulation consists of tasteless microspheres that can be easily sprinkled on semi-solid food such as yoghurt or jam, making it both advantageous and pleasant to use for children, the elderly and all people with epilepsy who have difficulties in swallowing. The manufacturing process used to produce Chronosphere® employs a highly innovative technology known as prilling, which produces microspheres of medication that are totally uniform in shape and have a regular surface. The matrix formulation eliminates the need for coating. The prilling process ensures a high level of reproducibility and a low variability of active substance release, which is virtually impossible to obtain using conventional manufacturing processes. Chronosphere® is the first application of prilling technology within the pharmaceutical industry. The process was developed by teams at the Sanofi-Synthélabo manufacturing facility in Ambarès, France. With more than 2,000 microspheres per gram of finished product, Chronosphere® greatly increases the surface area coming into contact with the mucous membranes, reducing the drug concentration per unit surface area. Plasma levels of valproic acid are maintained at the therapeutic efficacy threshold with once or twice daily dosing*. Swallowing bulky tablets or bitter syrup can be extremely unpleasant for people who have to take medicine on a daily basis. The Chronosphere® formulation is a very practical way for people with epilepsy to incorporate their medicine into their food and better comply with their treatment. The Chronosphere® formulation is also innovative in terms of packaging. The tiny microspheres are packaged in six unit dose stick packs, 50 mg, 100 mg, 250 mg, 500 mg, 750 mg and 1,000 mg of sodium valproate with each unit dose designated by a different colour. Stick packs are practical to use and can be easily carried around in a pocket or purse. Stick pack filling technology is ideal for products incorporating constituents with a low melting point, such as microsphere excipients, in that it avoid all contact with the product during sealing operations. Aluminium complex film is used to protect the microspheres from moisture. Despite the multitude of new antiepileptic drugs (AEDs) that have appeared in the past two decades, sodium valproate remains a mainstay therapy in the management of epilepsy. Valproate is a broad spectrum AED and is thus effective in the management of all seizure types. In addition, valproate is generally regarded as first line treatment for most forms of idiopathic and symptomatic generalised epilepsies. The vast cumulative experience of valproate's tolerability profile is based on both clinical studies and post-marketing experience. Most adverse events are benign, dose-related and easily managed. Weight gain is probably the most troublesome in daily practice. The more severe adverse events associated with valproate therapy are rare, well known and their occurrence may be minimised by the identification of at-risk populations (for hepatic and pancreatic toxicity) or the rationalisation of treatment in women planning to conceive and requiring therapy with valproate. "With over 35 years of clinical experience, valproate remains a cornerstone therapy in the management of all types of epileptic seizures. The new Chronosphere formulation is a welcome addition to the range of pharmaceutical dosage forms available for valproate. It should appeal to many people with epilepsy, both young and old," said Elinor Ben-Menachem, MD, PhD, Professor, Director of Clinical Pharmacology and Epilepsy, Department of Clinical Neuroscience, Sahlgrenska University Hospital, Göteborg, Sweden. The Chronosphère® formulation is currently marketed in France under the brand name MICROPAKINE® and will be launched** in most European countries end 2004 or 2005. * Dulac O, Alvarez JC, Pharmacotherapy 2004, in press ** range of commercialised dosages may be different from country to country Forward-Looking Statements This press release contains statements that constitute forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995. Forward-Looking statements are statements that are not historical facts. These statements include financial projections and estimates and their underlying assumptions, statements regarding plans, objectives and expectations with respect to future operations, products and services, and statements regarding future performance. Forward-looking statements are generally identified by the words "expect," "anticipates," "believes," "intends," "estimates" and similar expressions. Although Sanofi-Synthélabo's management believes that the expectations reflected in such forward-looking statements are reasonable, investors are cautioned that forward-looking information and statements are subject to various risks and uncertainties, many of which are difficult to predict and generally beyond the control of Sanofi-Synthélabo, that could cause actual results and developments to differ materially from those expressed in, or implied or projected by, the forward-looking information and statements. The following factors, among other risks and uncertainties that are described in our Form 20-F as filed with the SEC on April 2, 2004 and in the Reference Document filed with the French Autorité des Marchés Financiers on April 2, 2004, could cause actual results to differ materially from those described in the forward-looking statements: the ability of Sanofi-Synthélabo to expand its presence profitably in the United States; the success of Sanofi-Synthélabo's research and development programs; the ability of Sanofi-Synthélabo to protect its intellectual property rights; and the risks associated with reimbursement of health care costs and pricing reforms, particularly in the United States and Europe. Sanofi-Synthélabo does not undertake any obligation to provide updates or to revise any forward-looking statements. Investors and security holders may obtain a free copy of the Form 20-F filed with the SEC on April 2, 2004 and any other documents filed by Sanofi-Synthélabo with the SEC at www.sec.gov as well as of the Reference Document filed with the AMF on April 2, 2004 N° 04-0391 with the French Autorité des Marchés Financiers at www.amf-france.org or directly from Sanofi-Synthélabo on our web site at: www.sanofi-synthelabo.com. ------------------------------------------------------------ Ytterligere informasjon kan hentes på følgende hjemmeside: http://www.waymaker.no