Bilayer tablets of oxcarbazepine for controlled delivery and a process of preparation thereof

A process for the preparation of bilayer oxcarbazepine tablets by wet granulation comprising the following steps:

• I. Preparation of Immediate release granule I:
• Sifting of Oxcarbazepine, diluent, disintegrant through 40# sieve and mixing in a suitable mixer for 15 minutes;
• Granulating the blend with water in fluidized bed granulator;
• Drying of granules at 45-50° C. till LOD is between 2-3% w/w in fluidized bed drier;
• Sifting of dried granules through 16# sieve;
• and
• Lubricating the granules with lubricant, glidant (presifted through 40#) by mechanical mixing;
• II. Preparation of controlled release Granules II:
• Sifting of Oxcarbazepine, crystal habit modifier, matrix forming gelling agent, osmotically effective solutes, wetting agent through 30# sieve and mixed by mechanical means in an area with a controlled temperature and humidity;
• Granulating the blend using water and drying of granules at 45-50° C. in fluidized bed drier;
• and
• Sifting the dried granules through a 16# sieve and lubricating the granules with a lubricant (presifted through 40# sieve);
• III. Compression:
• Granules I and II are then compressed on a Manesty bilayer tablet compression machine.