I found this amusing quote with respect to Delzicol.
Reuters Article said...
"The FDA did not want us to have two products in the marketplace, because that would cause confusion to the patients," Chief Executive Roger Boissonneault said on a conference call to analysts. [Reuters Article]
Here is another article I found noting the differences between Delzicol and Asacol.
Benzinga Article said...
Morgan Stanley analysts said, "After perusing Delzicol(new Asacol)'s label, we believe that it may not qualify for any marketing exclusivity, implying that WCRX's time to effect conversion from Asacol may be very limited." The firm believes the major difference between the labels "is that Asacol tablets contain dibutyl phthalate as an inactive ingredient while Delzicol capsules contain dibutyl sebacate." [Benzinga Article]
The safety information for Delzicol notes that it used Asacol's studies for the basis of its approval rather than performing additional studies to confirm its safety and efficacy.