Testosterone (17ß- Hydroxyandost-4-en-3-on) and s the primary androgen or male reproductive (sex) hormone produced naturally in the body Therapeutically, testosterone is used in the management of hypogonadism, either congenital or acquired. It has a poor bioavailability due to extensive first-pass metabolism and very low half life (10 minutes) which makes an oral formulation nearly impossible

The development of a TTS on the contrary offers the benefit of continuing influx of testosterone into the system.

Currently, LTS has two matrix formulation under development varying in their manufacturing process. Both formulation however contain enhancer solutions. Stability studies are on going The release characteristics of the formulations were compared with the commercially available testosterone patch - Androderm.

The results of in vitro permeation studies show that Androderm has a higher local flux than LTS patch. However it is known, that Androderm's initial superiority in local flux is concomitant with relatively high skin irritations (as reported by arznei-Telegramm of Nov. 98) which are most probably due to the high local flux of ethanol contained the system.

Furthermore, even though the size of Androderm and LTS patch is nearly the same (ca. 36 cm2) the drug release area of the LTS patch is 4 times higher than that of Androderm, thus it is expected to exhibit much lower skin irritations A clinical study in comparison to Androderm is required.

The developed formulation have been manufactured on a pilot plan scale equipment.

The testosterone -TTS under development is covered by one formulation and two process manufacturing patents already granted.

Licensees sought to progress this product to market.