The therapeutic effectiveness of paliperidone in the treatment of schizophrenia has been limited by its poor oral bioavailability; hence, an alternative route could be appropriate. This study investigates the feasibility of developing a buccal film impregnated with paliperidone-loaded nanostructured lipid carriers (NLCs) and assesses the potential to enhance its bioavailability. Box-Behnken-based design optimization of NLCs was performed by examining the particles' physical characteristics. The polymeric film was used to load optimized NLCs, which were then assessed for their pharmaceutical properties, permeability, and pharmacokinetics. The optimization outcomes indicated that selected formulation variables had a considerable (p < 0.05) impact on responses such as particle size, entrapment efficiency, and % drug release. Desired characteristics such as a negative charge, higher entrapment efficiency, and nanoparticles with ideal size distribution were shown by optimized NLC dispersions. The developed film demonstrated excellent physico-mechanical properties, appropriate texture, good drug excipient compatibility (chemically stable formulation), and amorphous drug nature. A sustained Weibull model drug release (p < 0.0005) and superior flux (~5-fold higher, p < 0.005) were seen in NLC-loaded film compared to plain-drug-loaded film. The pharmacokinetics profile in rabbits supports the goal of buccal therapy as evidenced by significantly higher AUC0-12 (p < 0.0001) and greater relative bioavailability (236%) than the control. These results support the conclusion that paliperidone-loaded NLC buccal film has the potential to be an alternate therapy for its effective administration in the treatment of schizophrenia.
Keywords: Box-Behnken design; buccal film; nanostructured lipid carriers; paliperidone; pharmacokinetics.