Formulation and evaluation of sublingual delivery of piroxicam using thermosensitive polymer with an inverted Franz diffusion cell

Objectives The aim of the study was to prepare a sublingual formulation for piroxicam using a thermosensitive polymer and to evaluate its permeation through porcine sublingual mucosa. Methods Formulation technique utilized the transition property of poloxamer from solution state at room temperature to gel state at oromucosal temperature (37 °C). The permeation of the drug was evaluated using an inverted Franz diffusion cell technique that allowed the dosage form to be directly applied onto the substrate with required volume of saliva. The formulation was characterized for microscopy of the piroxicam crystals, sol–gel transition property and in‐vitro diffusion study. Key findings Poloxamer‐based formulation enhanced solubility and increased permeability of the piroxicam. Conclusion Poloxamer formulation with 0.1% w/w piroxicam delivered a cumulative amount of 11.99 ± 7.82 and 11.23 ± 1.79 μg/cm2, while non‐poloxamer formulation delivered 3.57 ± 2.20 and 4.60 ± 6.90 μg/cm2 with 0.1 and 0.5 ml artificial saliva, respectively, through porcine sublingual tissue in 6 h. A similar delivery profile was observed for 0.05% w/w piroxicam formulation as well.