Stronger pill at Iris.

In a year when large local companies such as Amgen and Hilton Hotels Corp. have chucked their poison pills, Iris International Inc., a small Chatsworth-based medical device company, is strengthening its dose. The board of the automated urinalysis equipment maker amended its stockholders' rights agreement to strengthen the company's anti-takeover provisions. It drastically raises the cost of purchasing large blocks of stock when someone attempts to purchase 20 percent or more of outstanding shares without board approval. Iris, whose-stock took a hit earlier this year on lackluster earnings and delay in signing contracts, has been on the rise since announcement of a major new customer in September.