Formulation and Evaluation of Quetiapine Fumarate Extended-Release Matrix Tablets Using Metolose 15000SR and HPMC K15CR

Introduction: Quetiapine Fumarate (QF) is a second-generation antipsychotic used to treat schizophrenia and bipolar depression. Extended-release (ER) tablets help improve patient compliance and reduce side effects by slowing down drug absorption. Method: In this study, QF-ER tablets were made using the wet granulation method with two polymers, Metolose 15000 SR and Hydroxypropylmethylcellulose (HPMC) K15CR, in different amounts. To check compatibility, QF was mixed with other ingredients and stored at room temperature for 15 days. There were no significant changes in color or odor, and infrared spectral analysis confirmed that QF was compatible with the polymers and other excipients, with no interactions. The prepared granules had good to excellent flowability, ensuring even tablet compression. The finished tablets were tested for weight, hardness, thickness, friability, drug content, drug release, and release kinetics. Results: All formulations had a good appearance without defects, and all values met pharmacopeial standards. Among the five formulations, F5 showed the best performance, releasing 98.77 % of the drug over 24 hours, like the market sample (97.21 % in 24 hours). The drug release from F5 followed the Hixson-Crowell model (R² = 0.9997), indicating that the release was controlled by both tablet erosion and diffusion. The release exponent (n = 0.6123) suggested a combination of swelling and diffusion as the drug release mechanism. Conclusions: F5 was identified as the best formulation, as it met all pharmacopeial requirements, had excellent physical properties, and provided a well-controlled, extended drug release for 24 hours, making it a strong alternative to the market.