Formulation Optimization and Evaluation of Metformin Hydrochloride Orally Disintegrating Tablets Using Spray Drying and D-Optimal Design of Experiments

Metformin hydrochloride (Met.HCl) is widely used for the management of type 2 diabetes mellitus (T2DM); however, conventional dosage forms can be inconvenient for individuals with dysphagia. This study aimed to develop orally disintegrating tablets (ODT) that rapidly disintegrate upon contact with saliva, thereby improving patient compliance. Met.HCl was spray-dried with selected excipients to enhance compressibility and mask its bitterness. A D-optimal design of experiments (DOE) was employed to optimize excipient ratios and compression parameters. The resulting Met.HCl ODT were evaluated for hardness, disintegration time, tensile strength, dissolution performance, and stability. The D-optimal DOE successfully predicted the optimal factors and responses with model validation confirming its reliability. The optimized Met.HCl ODT, formulated with spray-dried Met.HCl, exhibited excellent hardness (70 N), rapid disintegration (< 30 s), complete drug release within 5 min and maintained its physical stability over 6 months of accelerated storage. This study demonstrates that D-optimal DOE-based formulation optimization, combined with spray-dried Met.HCl, allows the development of ODT that balance fast disintegration and robust mechanical performance. The optimized Met.HCl ODT provides a patient-friendly alternative for individuals with swallowing difficulties while maintaining effective drug delivery.