Phosphagenics Limited (MELBOURNE, Australia), a biotechnology company focused on the discovery of new and cost effective ways to enhance the bioavailability, activity, safety, and delivery of proven pharmaceutical and nutraceutical products, announced that it has initiated a phase I clinical trial using its patented drug delivery system, TPM, for the targeted delivery of the nonsteroidal anti-inflammatory drug (NSAID), diclofenac. The trial will compare the bioavailability and penetration of the topically applied Voltaren^® gel (1% diclofenac sodium topical gel, Novartis), and Phosphagenics’ TPM/diclofenac (at 1% and 2% diclofenac concentrations). Voltaren Gel is indicated for the relief of the pain of osteoarthritis of joints amenable to topical treatment, such as the knees and those of the hands.

The open-label, single-center trial will evaluate dermal and systemic pharmacokinetics, and safety and tolerability in 12 healthy volunteers and will be conducted at the Centre for Pharmaceutical Research at the University of South Australia in Adelaide. Phosphagenics expects to report the results of this phase I trial in the first quarter of 2009.

In preclinical studies with TPM/diclofenac, Phosphagenics has demonstrated significant increases in skin penetration of diclofenac compared to Voltaren. While the exact transport mechanism of TPM is not yet fully characterized, in transdermal applications it appears that TPM works by forming an association with certain drugs, and then (via a transport mechanism contained within the dermis) the associated TPM/drug is efficiently transported through the skin. Once the drug has been transported across the skin, it disassociates from TPM. This efficient diffusion through skin creates a subcutaneous drug reservoir, and it is this pool that then allows for a sustained systemic delivery.