Topical anesthetic formulation

• US 20040131665A1
• Filed: 08/22/2003
• Published: 07/08/2004
• Est. Priority Date: 10/22/1999
• Status: Abandoned Application

• Current Assignee: Transdermatech, Inc.
• Original Assignee: Transdermatech, Inc.
• Inventors: Wepfer, Scott T.
• Application Number:
  US10/645,951
• Publication Number:
  US 20040131665A1
• Time in Patent Office: Days
• US Class Current: 424/449
• CPC Class Codes: A61K 31/137 Arylalkylamines, e.g. amphetamine, epinephrine, salbutamol, ephedrine or methadone
• CPC Class Codes: A61K 31/167 having the nitrogen of a carboxamide group directly attached to the aromatic ring, e.g. lidocaine, paracetamol
• CPC Class Codes: A61K 31/245 Amino benzoic acid types, e.g. procaine, novocaine salicylic acid esters A61K31/60
• CPC Class Codes: A61K 45/06 Mixtures of active ingredients without chemical characterisation, e.g. antiphlogistics and cardiaca
• CPC Class Codes: A61K 47/10 Alcohols; Phenols; Salts thereof, e.g. glycerol; Polyethylene glycols [PEG]; Poloxamers; PEG/POE alkyl ethers
• CPC Class Codes: A61K 9/0014 Skin, i.e. galenical aspects of topical compositions non-active ingredients are additionally classified in A61K47/00; A61K9/0009, A61K9/0021, A61K9/7015, A61K9/7023 take precedence; cosmetic preparations A61K8/00, A61Q; preparations for wound dressings or bandages A61L26/00

Abstract

The topical anesthetic gel formulation of the present invention preferably includes lidocaine, USP as the active anesthetic ingredient with a skin penetration enhancer and a gelling agent. This invention deals with problems commonly associated with topical application of local anesthetics such as: slow onset of action; need for occlusion; messiness of creams, ointments or gels; and rapid loss of effect due to rapid systemic dispersion. The invention permits enhanced penetration of the anesthetic and thereby allows for a lesser total dosage of pharmaceutically active ingredient. The use of a lesser total dosage also decreases systemic toxicity.

Claims

1. A formulation comprising at least one anesthetic compound selected from the group consisting of procaine, lidocaine, tetracaine and salts thereof;

and a skin penetration enhancer, and a gelling agent in an anhydrous mixture.

2. The formulation of claim 1 wherein said skin penetration enhancer is at least one compound selected from the group consisting of:

benzyl alcohol, propylene glycol, and ethoxydiglycol.

3. The formulation of claim 1 wherein at least two skin penetration enhancers are present.

4. The formulation of claim 1 wherein said at least one anesthetic compound is present in said formulation from 1 to 25 total weight percent.

5. The formulation of claim 3 further comprising a third skin penetration enhancer.

6. The formulation of claim 1 wherein said at least two anesthetic compounds are procaine, lidocaine and tetracaine, or salts thereof.

7. The formulation of claim 1 wherein lidocaine is present from 0.5-6 total weight percent.

8. The formulation of claim 1 wherein said skin penetration enhancer is present from 0 to 95 total weight percent.

9. The formulation of claim 1 wherein said skin penetration enhancer is present from 25 to 45 total weight percent.

10. The formulation of claim 1 wherein the gelling agent is a cellulosic polymer.

11. The formulation of claim 1 wherein the gelling agent is hydroxypropyl cellulose.

12. The formulation of claim 11 wherein the hydroxypropyl cellulose has a viscosity ranging between 1000 and 2000 centipoise at 25 degrees centigrade.

13. The formulation of claim 12 wherein the concentration of hydroxypropyl cellulose ranges from 0.5-5 total weight percent.

14. The formulation of claim 1 further comprising a dispersing agent.

15. The formulation of claim 1 further comprising an ingredient selected from the group consisting of:

preservative, fragrance, buffer, and an emollient.

16. The formulation of claim 1 further comprising a therapeutic agent.

17. The formulation of claim 16 wherein the therapeutic agent is selected from the group consisting of:

analgesics, anxiolytic compounds, antiarrhythmics, antibacterials, antibiotics, anticoagulants, anticonvulsants, antifungals, antihistamines, anti-inflammatories, antivirals, bronchodilators, calcium channel blockers, cytotoxics and anticancer agents, cytokines, growth factors, immunosuppressives, muscle relaxants, psychotherapeutics, sympathomimetics, vasodilators, vitamins, and combinations of these.

18. The formulation of claim 16 wherein the therapeutic agent is an anti-itch compound.

19. A method for reducing pain sensation, the method comprising the steps of:

applying a therapeutically effective amount of an anhydrous gel anesthetic formulation according to claim 1 to the area of an individual'"'"'s skin to be anesthetized; and

allowing the gel anesthetic to remain in contact with the area for a period of time sufficient to reduce pain sensation.

20. The method of claim 19 further comprising the step of:

applying a therapeutically effective amount of an anesthetic formulation comprising a topical anesthetic compound, a skin penetration enhancer and a volatile co-solvent, to the area to be anesthetized.

21. A method for reducing pain associated with the application of laser energy to the skin, said method comprising the step of applying a therapeutically effective amount of a topical anesthetic according to claim 1 to the area of the skin to be treated prior to the application of laser energy.

22. A commercial kit comprising at least one topical anesthetic compound formulated according to claim 1, together with instructions for use thereof as a topical anesthetic.

23. The commercial kit of claim 22 further comprising a second topical anesthetic, said second topical anesthetic comprising a skin penetration enhancer and a volatile co-solvent.

24. A method of local anesthesia comprising the step of applying to intact skin or oral mucosa the formula of claim 1.