Safe, effective first-pass inhibiting compounds and citrus-derived substances are provided. Formulations containing the compounds are also provided as are methods for inhibiting the first pass effect.
This application is a Continuation of U.S. application Ser. No. 11/212,909, filed Aug. 29, 2005, which is a Continuation of U.S. application Ser. No. 10/647,444, filed Aug. 26, 2003, now abandoned; which is a Continuation of U.S. application Ser. No. 09/916,500, filed Jul. 3, 2001, now U.S. Pat. No. 6,660,766; which is a Continuation of U.S. application Ser. No. 09/644,860, filed Aug. 24, 2000, now U.S. Pat. No. 6,309,687; which is a Continuation of U.S. application Ser. No. 09/455,911, filed Dec. 7, 1999, now U.S. Pat. No. 6,162,479; which is a Continuation of U.S. application Ser. No. 09/255,874, filed Feb. 23, 1999, now U.S. Pat. No. 6,054,477; which is a Continuation of U.S. application Ser. No. 08/997,259, filed Dec. 23, 1997, now U.S. Pat. No. 6,063,809; which is a 119(e) of U.S. Provisional Application Ser. No. 60/056,382, filed Aug. 26, 1997.
