Simulations Plus Releases GastroPlus Version 4.0; Upgrades Improve Accuracy and Convenience of Flagship Product for Pharmaceutical Research.

Business Editors/Health/Medical Writers

LANCASTER, Calif.--(BUSINESS WIRE)--Oct. 15, 2003

Simulations Plus, Inc. (OTCBB:SIMU), the leading provider of ADME neural net and absorption simulation software for pharmaceutical discovery and development, today announced that it is releasing Version 4.0 of its widely used GastroPlus(TM) software, which simulates the oral absorption of drugs in humans and in laboratory animals.

"This new version incorporates a number of major improvements to GastroPlus to further improve the accuracy and convenience of the software for our users," said Dr. Michael Bolger, director of Life Sciences for the Company. "We continue to move steadily toward more physiologically-based modeling, meaning that the equations within GastroPlus are more and more representative of actual human and animal physiologies rather than mathematical abstractions. The model of the gastrointestinal tract now includes one that is more physiologically correct, in addition to the mathematically convenient 'equal transit time' model we have used until now. The addition of enterohepatic circulation, which simulates how some drugs are collected in the gall bladder and then secreted back into the small intestine, mostly at meal times, and reabsorbed across the intestinal wall, enables researchers to assess and predict the 'double peak' phenomenon seen in the blood concentration-time profiles for these drugs. This version also includes a number of new convenience features that make GastroPlus faster and easier to use for complex analyses."

"GastroPlus 4.0 is part of the ongoing support and upgrades we provide as an integral part of our annual license business model," said Ron Creeley, vice president of Marketing and Sales. "Unlike programs that remain static, we reinvest our revenues into improving our products both by responding to requests from customers and by identifying and implementing new capabilities that help us in using the software ourselves in contract studies. GastroPlus is the most widely used software in the world for oral absorption simulation, pharmacokinetics, and pharmacodynamics. Almost all of the top 20 companies and many smaller companies are using it today to reduce the time and expense of bringing new drugs to market."

About Simulations Plus, Inc.

Simulations Plus, Inc. is a premier developer of groundbreaking drug discovery and development simulation software, which is licensed to and used in the conduct of drug research by major pharmaceutical and biotechnology companies worldwide. The Company has two other businesses, Words+, Inc. and FutureLab(TM), which are based on its proprietary software technologies. Simulations Plus, Inc., is headquartered in Southern California and trades on the OTCBB under the symbol "SIMU." For more information, visit our Web site at www.simulations-plus.com.

Safe Harbor Statement Under the Private Securities Litigation Reform Act of 1995 -- With the exception of historical information, the matters discussed in this press release are forward-looking statements that involve a number of risks and uncertainties. The actual future results of the Company could differ significantly from those statements. Factors that could cause or contribute to such differences include, but are not limited to: the number of new pharmaceutical and biotech companies that adopt the Company's modeling and simulation technologies, the ability of the Company to maintain its competitive advantage, the general economics of the pharmaceutical industry, the availability of working capital, and a sustainable market. Further information on the Company's risk factors is contained in the Company's quarterly and annual reports as filed with the Securities and Exchange Commission.