Analgesic composition of topically applied nonsteroidal antiinflammatory drugs and opioids
It has been estimated that over hundreds million patients suffer from either chronic postoperative or chronic neuropathic pain annually in the whole world. Global pain and inflammation markets are growing at an average of 30% per year and are estimated to reach the $40 billion level by 2025. In this area where no current single drug treatment is effective in more than 50% of patients, novel therapeutic approaches are an urgent priority.
The present invention relates to pharmaceutical formulations comprising at least two compounds, one effecting opioid analgesia and one effecting cyclooxygenase 1 and 2 activity, in amounts sufficient to potentiate an antino-ciceptive response when both compounds are topically administered in a physiologically acceptable topical excipient. The pharmaceutical formulations of the present invention are used to prevent or relieve acute pain and chronic peripheral neuropathy and/or neuropathic inflammation in a patient in need of such treatment. Topical administration of a topical NSAID/opioid synergistic drug formulation provides a superior method for the clinical treatment of peripheral pain.
In the pre-clinical studies has been found that topical administration of a composition comprising certain relative amounts of opioids and NSAID results in the synergistic potentiation of peripheral antinociceptive responses. Use of topically administered compositions comprising the proportions of opioids and topical NSAID described and claimed herein provides an important new approach to management of the peripheral pain
Method.The study was conducted as a crossover, randomized, double-blind, placebo-controlled comparison of two doses of Diclometh gel (diclofenac plus methadone, 1:1) administered topically in 21 human healthy male participants. Capsaicin intradermal injections were used as a human model of pain.
Results. A dose-dependent, antiallodynic and antihyperalgesic effects of Diclometh was found. No serious local or central side effects were observed at any dosage of Diclometh gel.
Conclusion. Indication of antiallodynic effect of 0.2% Diclometh was found in the human experimental neuropathic model of pain. Additionally, it was demonstrated that Diclometh was safe to use.
The phase IIa clinical study is needed to determine clinically effective doses of the Diclometh gel (diclafenac+methadon) for the treatment of the peripheral neuropathic pain.
The clinical trial performed in Denmark has been demonstrated the efficacy and lacking of the central and local side effects of the topical combination of diclofenac and methadon foe experimental human pain. So, we are looking for the sale our patents and detailed technological methods of the analgesic gel preparation. This is our main goal, but we are open to discuss other possibilities as well.