The mucoadhesive drug delivery system has received great deal of attention over the past few decades. The major advantages of this system are to prolong the drug residence at a specific site of delivery and solve bioavailability problems. The major focus of this book is to explain the current research tools for designing of mucoadhesive microparticles of rabeprazole sodium and tolterodine tartrate by non-aqueous solvent evaporation technique using ethylcellulose and selected mucoadhesive polymers. The prepared microparticles of the above drugs were characterized for particle size, drug content, swelling index, mucoadhesive strength etc. In-vitro drug release study for both drugs suggested that formulation containing tolterodine tartrate with ethylcellulose based chitosan and rabeprazole sodium with ethylcellulose based HPMC K100M showed consistent drug release up to 24h. Accelerated stability study of optimized formulations such as F4 and F6c up to 6 and 3 months respectively.