Formulation and evaluation of fast dissolving sublingual film of linagliptin

Linagliptin is a selective inhibitor of the enzyme dipeptidyl peptidase-4 (DPP-4), which metabolizes the naturally occurring incretins- like peptide-1 and glucose- dependent insulinotropic polypeptide resulting in enhanced glucose- dependent insulin secretion from the pancreas and decreasedhepatic glucose production. Mucoadhesive films for sublingual use were prepared by using polymers such as Polyvinyl alcohol, Hydroxy propyl methyl cellulose, Polyvinyl pyrrolidone, Mannitol, Polyethylene glycol 400 in different ratios by the solvent casting method. The IR Spectral studies showed no interaction between drug and polymer. The prepared formulations show satisfactory result, when subjected to various physicochemical tests such as uniformity of weight, thickness, Surface pH, folding endurance, uniformity of drug content, swelling index, bioadhesive strength. The formulations were also subjected to evaluation of in vitro drug release by using USP Dissolution Apparatus. Ex vivo drug release and permeation studies were also carried out using porcine membrane as the model. All the formulation showed 76.22-100.85% release within 5 min by the in vitro method. The stability studies conducted for a period of eight weeks showed that there was no appreciable change in drug content, surface pH and in vivo drug release when stored at refrigeration temp. 4-60 C, room temp 28-300C and 40-450C.