Formulation, evaluation, and optimisation of soft chewable lozenges using Box-Behnken design for the treatment of...

Schizophrenia is a long-term psychiatric disorder that generally requires long-term pharmacotherapy, where poor medication adherence and delayed therapeutic onset remain major challenges. The present study is focused on formulating, optimising, and evaluating soft chewable patient-friendly lozenges of brexpiprazole to improve dissolution, patient compliance, and drug absorption in individuals with schizophrenia. Soft chewable lozenges were prepared by a melt-pour method and optimised using a three-factor, three-level Box-Behnken design. PEG 1000, acacia, and colloidal silica were selected as formulation variables, while hardness and the time required for 80% drug release were considered as responses. The prepared formulations were subjected to physicochemical evaluation, dissolution testing, and stability assessment. All batches underwent physicochemical evaluation parameters, including in vitro dissolution and stability. The optimised formulation (S8) underwent in vivo pharmacokinetic evaluation on rabbits. Hardness values ranged between 2.2 and 5.6 kg/cm² and drug release times (80% release) of 18.55-26.23 min. The optimum results were observed for batch S8 with 96.12% drug release and low hardness (2.2 kg/cm²). In vivo studies confirmed improvement in drug absorption with reduced T_max (2 h) and increased C_max (34.86 ng/mL) in comparison with the reference standard. Stability testing confirmed the stability of the optimised formulation throughout the study period. The optimised soft chewable brexpiprazole lozenges are a potential dosage form with improved patient acceptability, increased adherence, and improved systemic absorption, thus supporting its potential in the management of schizophrenia.