Effects of mucoadhesive polymers on released particles and drug release in solid lipid particle-based buccal tablets

Background: Mucoadhesive polymers play a critical role in controlled-release tablets for buccal drug delivery. Objective: This research aimed to investigate the characterization and mechanisms of solid lipid particle-based tablets with different mucoadhesive polymers for buccal delivery. Methods: Prednisolone (PSL)-loaded solid lipid particles (SLPs) were conventionally prepared by ultrasonication. The freeze-drying method was used to convert the SLP suspension into a solid dosage form for buccal delivery by using mucoadhesive polymers. Results: All formulations showed over 80% drug release after 6 h, which followed immediate and sustained release patterns depending on the SLP type. However, the different polymers in the formulations resulted in different mucoadhesion times and drug release and drug permeability profiles. HPMC 4000 showed higher drug permeation (3327 μg vs. 2589 μg after 6 h) but a shorter mucoadhesion time than Carbopol (197 min vs. 361 min). In addition, surface morphology, swelling and erosion, particle size and zeta potential were also noted for the different mechanisms for buccal tablet design with different controlled release profiles. Conclusion: The results of this work indicate a good strategy for the selection of mucoadhesive polymers for SLP-based tablets in improving the bioavailability of poorly water-soluble drugs.