The data from the PK study showed that testosterone blood levels were similar on days 14, 21, 42 and 63 of the study, indicating that there was no buildup of testosterone blood levels with daily LibiGel treatment. Additionally, free and bioavailable testosterone returned to baseline levels within 36-48 hours after the last dose of LibiGel, indicating effective elimination after dosing is discontinued. The testosterone blood levels produced in this study were very similar to those seen in the BioSante LibiGel Phase II efficacy trial reported previously, and they were very similar to blood levels observed in transdermal testosterone patch studies, which also demonstrated efficacy in the treatment of HSDD. Importantly, in the LibiGel PK study, there were no measurable increases in blood levels of the most active estrogen, estradiol, which could have occurred as a result of the conversion of testosterone to estradiol. BioSante plans to present the full PK study results at an upcoming medical meeting.

"Significantly, none of the subjects in the LibiGel PK study had average testosterone concentrations above the normal range for younger, premenopausal women, a finding that may be a key component in the safety evaluation of LibiGel by FDA," noted Michael C. Snabes, M.D., Ph.D., senior vice president of medical affairs at BioSante. "This finding adds to our confidence that the results of our ongoing, long-term safety study of LibiGel will be favorable."

Source BioSante Pharmaceuticals, Inc.