Method for treating nerve injury pain associated with shingles

Abstract

Methods and compositions are offered for reducing nerve injury pain associated with shingles (herpes-zoster and post-herpetic neuralgia), where intradermal delivery of lidocaine is maintained for a predetermined period of time. The lidocaine appears to specifically affect the damaged nerve fibers, while leaving the undamaged and normal nerve fibers with retention of response to other stimuli. Lidocaine formulations are provided which allow for the necessary dosage of the lidocaine in the dermis during the period of treatment. The formulation may be covered with an occlusive or non-occlusive dressing, which protects the lidocaine formulation from mechanical removal and enhances the transport of the lidocaine into the dermis. Long term relief is realized after maintenance of the administration of lidocaine has been terminated.

What is claimed is:  
     
       1. A method for treating neuropathies causing pain at a site with the induction of analgesia by intradermal administration, said method comprising: 
       applying at the site of pain, a plaster or gel, comprising from about 2 to 10% by weight of lidocaine at least in part as the free base in a formulation which provides for intradermal transport of said lidocaine,  
       whereby said lidocaine is transported intradermally to provide for analgesia at the site of said neuropathy.  
     
     
       2. A method according to  claim 1 , wherein said formulation comprises at least one of propylene glycol and glycerin as a co-solvent. 
     
     
       3. A method according to  claim 2 , wherein said co-solvent comprises at least one of D-sorbitol and water. 
     
     
       4. A method according to  claim 1 , wherein said applying is with a plaster comprising a cover selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, polyethylene, synthetic rubber, woven polyester fabric and non-woven polyester fabric. 
     
     
       5. A method for treating neuropathies causing pain at a site with the induction of analgesia by intradermal administration, said method comprising: 
       applying at the site of pain, a plaster comprising: a physiologically acceptable adhesive, comprising from about 2 to 10% by weight of lidocaine at least in part as the free base, water, sodium polyacrylate, and propylene glycol, in a formulation which provides intradermal transport of said lidocaine; and  
       a non-woven polyester covering;  
       whereby said lidocaine is transported intradermally to provide for analgesia at the site of neuropathy.  
     
     
       6. A method according to  claim 5 , wherein said lidocaine is present in 5% by weight. 
     
     
       7. A method for treating neuropathies causing pain at a site where the induction of analgesia by intradermal administration, said method comprising: 
       applying at the site of pain, a gel, comprising from about 2 to 10% by weight of lidocaine at least in part as the free base in a formulation which provides for intradermal transport of said lidocaine,  
       whereby said lidocaine is transported intradermally to provide for analgesia at the site of said neuropathy.  
     
     
       8. A composition for treating neuropathies causing pain at a site by inducing analgesia by intradermal administration, said composition comprising: 
         a plaster or gel comprising from about  2  to  10   %  by weight of lidocaine at least in part as the free base in a formulation which provides for intradermal transport of said lidocaine.   
     
     
       9. The composition according to  claim 8 , wherein said lidocaine is present in about  5  to  10 %  weight.   
     
     
       10. The composition according to  claim 8 , wherein said formulation comprises at least one of propylene glycol and glycerin as a co- solvent.   
     
     
       11. The composition according to  claim 10 , wherein said co- solvent further comprises at least one of D - sorbitol and water.   
     
     
       12. The composition according to  claim 8 , wherein said composition comprises plaster which further comprises a cover selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, polyethylene, synthetic rubber, woven polyester fabric and non- woven polyester fabric.   
     
     
       13. The composition according to  claim 8 , wherein said formulation provides for at least  8  hours of analgesia. 
     
     
       14. A plaster for treating neuropathies causing pain at a site by inducing analgesia by intradermal administration, said plaster comprising: 
         a physiologically acceptable adhesive, comprising from about  2  to  10   %  by weight of lidocaine at least in part as the free base water, sodium polyacrylate, and propylene glycol in a formulation which provides intradermal transport of said lidocaine; and a non - woven polyester covering.   
     
     
       15. The plaster according to  claim 14 , wherein said lidocaine is present in about  5  to  10 %  by weight.   
     
     
       16. A gel for treating neuropathies causing pain at a site by inducing analgesia by intradermal administration, said gel comprising: 
         from about  2  to  10   %  by weight of lidocaine at least in part as the free base in a formulation which provides for intradermal transport of said lidocaine, wherein said formulation comprises  70  to  90   %  weight of an anhydrous vehicle,  0 . 1  to  5   %  weight of a physiologically acceptable gelling agent,  2  to  20   %  weight of a nonionic surfactant, and up to  10   %  weight of physiologically acceptable excipients.   
     
     
       17. The gel according to  claim 16 , wherein said lidocaine is present in about  5  to  10 %  by weight.   
     
     
       18. The gel according to  claim 16 , wherein said anhydrous vehicle is selected from the group consisting of ethanol, isopropanol, propylene glycol, and glycerin. 
     
     
       19. The gel according to  claim 16 , wherein said physiologically acceptable gelling agent is at least one of Carbomer  940  neutralized with diisopropanolamine and neutralized polyacrylic acid. 
     
     
       20. The gel according to  claim 16 , wherein said nonionic surfactant is a sorbitan ester. 
     
     
       21. The gel according to  claim 16 , wherein said formulation further comprises a salicylate compound. 
     
     
       22. A patch comprising: 
         a  10 × 14  cm non - woven polyester backing and a physiologically acceptable adhesive comprising  700  mg of lidocaine base, water glycerin, D - sorbital, sodium polyacrylate, sodium carboxymethyl cellulose, and propylene glycol.