Sumatriptan succinate sublingual fast dissolving thin films: formulation and in vitro/in vivo evaluation

Sumatriptan succinate (SS) is a 5-HT1 receptor agonist used in the treatment of migraine having poor bioavailability (15%) due to its extensive first-pass effect. The aim of this work was to prepare SS sublingual fast dissolving thin films (SFDTFs) allowing the drug to directly enter the systemic circulation and bypassing the first-pass metabolism. Plain thin films were prepared using solvent casting technique adopting 2(3) × 3 factorial design to study the effect of polymer and plasticizer type and concentration on mechanical properties and in vitro disintegration time of the plain prepared films using Design-Expert®. Medicated films were prepared after addition of 35 mg SS to each of the two selected plain formulae (F6 and F7) having desirability values above 0.9 showing the values of: 0.038, 0.039 kgf/mm(2) and 156.24, 164.16% and 0.0248, 0.0240 kgf/mm(2) as tensile strength, percent elongation and elastic modulus, respectively. PVP K30 was efficient as crystallization inhibitor in retarding SS crystallization. Pharmacokinetic study of the optimum formula F7 (PVP K30:SS (1:1 w/w)) in healthy human volunteers using LC/MS/MS revealed a shorter tmax (0.25 h) compared to Imitrex® tablet 25 mg (2 h) which is considered promising especially for the rapid relief of acute migraine attacks.