Layered pharmaceutical formulations

Abstract

In one embodiment a layered pharmaceutical formulation includes two or more pharmaceutical layers and an intermediate layer disposed between at least two of the two or more pharmaceutical layers, the intermediate layer configured to dissolve in vivo to thereby leave the two or more pharmaceutical layers substantially intact. In one embodiment, an active pharmaceutical ingredient in at least one of the pharmaceutical layers is selected from bupropion, zonisamide, naltrexone, topiramate, phentermine, metformin, olanzapine and fluoxetine.

What is claimed is: 
     
         1 . A layered pharmaceutical formulation for the administration of two or more active pharmaceutical ingredients comprising:
 a first pharmaceutical layer comprising zonisamide;   a second pharmaceutical layer comprising bupropion; and   an intermediate layer disposed between the first and the second pharmaceutical layers.   
     
     
         2 . The layered pharmaceutical formulation of  claim 1 , wherein the intermediate layer comprises a monosaccharide sugar, a disaccharide sugar or a starch. 
     
     
         3 . The layered pharmaceutical formulation of  claim 2 , wherein the intermediate layer comprises lactose. 
     
     
         4 . The layered pharmaceutical formulation of  claim 1 , wherein the intermediate layer is configured to rapidly dissolve in vivo, and thereby leave the first and the second pharmaceutical layers substantially intact but physically separated. 
     
     
         5 . The layered pharmaceutical formulation of  claim 4 , wherein the first and the second pharmaceutical layers separate in vivo in less than 1 minute. 
     
     
         6 . The layered pharmaceutical formulation of  claim 1 , wherein the bupropion comprises a sustained-release bupropion 
     
     
         7 . The layered pharmaceutical formulation of  claim 6 , wherein the second pharmaceutical layer comprises between about 50 mg and about 200 mg of sustained-release bupropion. 
     
     
         8 . The layered pharmaceutical formulation of  claim 6 , wherein the second pharmaceutical layer comprises between about 75 mg and about 150 mg of the sustained-release bupropion. 
     
     
         9 . The layered pharmaceutical formulation of  claim 6 , wherein the second pharmaceutical layer comprises between about 85 mg and about 100 mg of the sustained-release bupropion. 
     
     
         10 . The layered pharmaceutical formulation of  claim 6 , wherein the zonisamide comprises a sustained-release zonisamide. 
     
     
         11 . The layered pharmaceutical formulation of  claim 10 , wherein the dissolution profile of sustained-release zonisamide in the pharmaceutical formulation is substantially the same as a single compressed tablet of naltrexone having the same size and shape as the first pharmaceutical layer, and wherein the dissolution profile of sustained-release bupropion in the layered pharmaceutical formulation is substantially the same as a single compressed tablet of the same pharmaceutical composition, size and shape as the second pharmaceutical layer.