Controlled release formulation of divalproex sodium

Abstract

A new oral polymeric controlled release formulation suitable for the once-a-day administration of valproate compounds, such as divalproex sodium, has been discovered. This formulation exhibits significant advantages over the sustained release valproate formulations of the prior arts. This formulation minimnizes the variation between peak and trough plasma levels of valproate over a 24 hour dosing period. This formulation follows a zero-order release pattern thus producing essentially flat plasma levels of valproate, once steady-state levels have been achieved. This results in a significantly lower incidence of side effects for patients consuming such a formulation.

We claim:  
     
         1 . A oral polymeric controlled release formulation suitable for once-a-day administration comprising: 
 a) divalproex sodium;    b) said divalproex sodium is in association with a sufficient quantity of a pharmaceutically acceptable polymer, and;    c) when said formulation is ingested orally, said formulation produces a C max  that is statistically significantly lower than the C max  produced by a delayed release divalproex sodium tablet, when each is determined at steady state in a healthy fasting population.    
     
     
         2 . The formulation according to  claim 1  which produces a C min  that is not statistically significantly different from the C min  produced by said delayed release divalproex sodium tablet, when each is determined at steady state in a healthy fasting population.  
     
     
         3 . The formulation according to  claim 1  in which said formulation produces an AUC value that is equivalent to the AUC value generated by said divalproex sodium delayed release tablet, when each is determined at steady state in a healthy fasting population.  
     
     
         4 . The formulation according to  claim 1  which: 
 a) produces a C min  that is not statistically significantly different from the C min  produced by said delayed release divalproex sodium tablet, when each is determined at steady state in a healthy fasting population, and;  
 b) said formulation produces an AUC value that is equivalent to the AUC value generated by said divalproex sodium delayed release tablet, when each is determined at steady state in a healthy fasting population.  
 
     
     
         5 . The formulation according to  claim 4  which produces a DFL that is lower than the DFL produced said delayed release divalproex sodium tablet, when each is determined at steady state in a healthy fasting population.  
     
     
         6 . The formulation according to  claim 1  in which said formulation is a matrix system, an osmotic pump system or a reservoir polymeric system.  
     
     
         7 . A oral polymeric controlled release formulation suitable for once-a-day administration comprising: 
 a) divalproex sodium;    b) said divalproex sodium is in association with a pharmaceutically acceptable polymer, and;    c) when said formulation is ingested orally said formulation produces: 
 i. a C max  that is statistically significantly lower than the C max  produced by a delayed release divalproex sodium tablet, when each C max  is determined at steady state in a healthy fasting population,  
 ii. a C min  that is not statistically significantly different from the C min  produced by said delayed release divalproex sodium tablet, when each C min  is determined at steady state in a healthy fasting population, and;  
 iii. said formulation produces an AUC value that is equivalent to the AUC value generated by said divalproex sodium delayed release tablet, when each AUC is determined at steady state in a healthy fasting population.  
   
     
     
         8 . The formulation according to  claim 7  in which said formulation produces steady state peak plasma valproate levels that are about 10 to about 20% lower than that produced by a said delayed release divalproex sodium tablet.  
     
     
         9 . A method for the treatment of migraine comprising the administration of a formulation according to  claim 1  to a patient in need thereof.  
     
     
         10 . A method for the treatment of epilepsy comprising the administration of a formulation according to  claim 1  to a patient in need thereof.  
     
     
         11 . A method for the treatment of mania associated with a bipolar disorder comprising the administration of a formulation according to  claim 1  to a patient in need thereof.  
     
     
         12 . A method for the reduction of side effects associated with divalproex sodium therapy comprising the administration of a formulation according to  claim 1 .  
     
     
         13 . A oral polymeric controlled release formulation suitable for once-a-day administration comprising: 
 a) a valproate compound;    b) said valproate compound is in association with a sufficient quantity of a pharmaceutically acceptable polymer, and;    c) when said formulation is ingested orally, said formulation produces a C max  that is statistically significantly lower than the C max  produced by a bid dosage form of said valproate compound, when each is determined at steady state in a healthy fasting population.    
     
     
         14 . The formulation according to  claim 13  which produces a C min  that is not statistically significantly different from the C min  produced by said bid dosage form when each is determined at steady state in a healthy fasting population.  
     
     
         15 . The formulation according to  claim 13  in which said formulation produces an AUC value that is equivalent to the AUC value generated by said bid valproate dosage form, when each is determined at steady state in a healthy fasting population.  
     
     
         16 . The formulation according to  claim 13  which: 
 a) produces a C min  that is not statistically significantly different from the C min  produced by said bid valproate dosage form, when each is determined at steady state in a healthy fasting population, and;  
 b) said formulation produces an AUC value that is equivalent to the AUC value generated by said bid valproate dosage form, when each is determined at steady state in a healthy fasting population.  
 
     
     
         17 . The formulation according to  claim 13  which produces a DFL that is not statistically significantly different than the DFL by produced said bid valproate dosage form, when each is determined at steady state in a healthy fasting population.  
     
     
         18 . The formulation according to  claim 13  in which said formulation is a matrix system, an osmotic pump system or a reservoir polymeric system.  
     
     
         19 . An oral matrix formulation suitable for once-a-day administration comprising: 
 a) from about 40 to about 80 w/w% of divalproex sodium;    b) a sufficient quantity of a pharmaceutically acceptable polymer, and;    c) when said formulation is ingested orally: 
 i. said formulation produces a C max  that is statistically significantly lower than the C max  produced by a delayed release divalproex sodium tablet, when each is determined at steady state in a healthy fasting population,  
 ii. a C min  that is not statistically significantly different from the C min  produced by said delayed release divalproex sodium tablet, when each C min  is determined at steady state in a healthy fasting population, and;  
 iii. said formulation produces an AUC value that is equivalent to the AUC value generated by said divalproex sodium delayed release tablet, when each AUC is determined at steady state in a healthy fasting population.  
   
     
     
         20 . A oral osmotic pump formulation suitable for once-a-day administration comprising: 
 a) divalproex sodium;    b) said divalproex sodium is in association with a sufficient quantity of a pharmaceutically acceptable semipermeable polymer, and;    c) when said formulation is ingested orally: 
 i. said formulation produces a C max  that is statistically significantly lower than the C max  produced by a delayed release divalproex sodium tablet, when each is determined at steady state in a healthy fasting population,  
 ii. a C min  that is not statistically significantly different from the C min  produced by said delayed release divalproex sodium tablet, when each C min  is determined at steady state in a healthy fasting population, and;  
 iii. said formulation produces an AUC value that is equivalent to the AUC value generated by said divalproex sodium delayed release tablet, when each AUC is determined at steady state in a healthy fasting population.  
   
     
     
         21 . A reservoir polymeric formulation suitable for once-a-day administration comprising: 
 a) divalproex sodium;    b) said divalproex sodium is in association with a sufficient quantity of a pharmaceutically acceptable polymer, and;    c) when said formulation is ingested orally: 
 i. said formulation produces a C max  that is statistically significantly lower than the C max  produced by a delayed release divalproex sodium tablet, when each is determined at steady state in a healthy fasting population,  
 ii. a C min  that is not statistically significantly different from the C min  produced by said delayed release divalproex sodium tablet, when each C min  is determined at steady state in a healthy fasting population, and;  
 iii. said formulation produces an AUC value that is equivalent to the AUC value generated by said divalproex sodium delayed release tablet, when each AUC is determined at steady state in a fasting population.