Development and characterization of Eudragit based mucoadhesive buccal patches of salbutamol sulfate

AbstractFor systemic drug delivery, the buccal region offers an attractive route of drug administration. Salbutamol sulfate is a short-acting β2-adrenergic receptor agonist used for the relief of bronchospasm in conditions such as asthma and chronic obstructive pulmonary disease. It’s oral bioavailability is ∼40% due to extensive first pass metabolism. Salbutamol sulfate patches were prepared using Eudragit L-100, HPMC, PVA and Carbopol 934 in various proportions and combinations using PEG-400/PG as plasticizers. Patches were laminated on one side with a water impermeable backing layer for unidirectional drug release. The thickness of medicated patches were ranged between 0.23±0.008 and 0.59±0.007mm and mass varied between 65.23±3.3 and 117.92±4.2mg. Patches showed an increase in mass and swelling index with PEG-400 when compared with PG. The surface-pH of patches ranged between 6 and 7. Formulations E7 (7.5mL Eudragit L-100, 15mL HPMC K4M, 7.5mL PVA and 2mL PEG-400), E12 (7.5mL Eudragit L-100, 7.5mL PVA, 15mL Carbopol and 2mL PEG-400), F7 (7.5mL Eudragit L-100, 15mL HPMC K4M, 7.5mL PVA and 2mL PG), and F12 (7.5mL Eudragit L-100, 7.5mL PVA, 15mL Carbopol and 2mL PG) showed high folding endurance. Residence time of the tested patches ranged between 101 and 110min. The maximum in vitro release was found to be 99.93% over a period of 120min for formulation F12. Data of in vitro release from patches were fitted to different kinetic models such as Higuchi and Korsmeyer–Peppas models to explain the release profile. Formulations E7 and F7 were best fitted to the non-Fickian, where as formulations E12 and F12 showed Fickian/anomalous drug release. Stability studies indicated that there was no change in the chemical and physical characteristics during the test period