The impacts of method selectivity and binders on the properties of carbamazepine granules and their applications: A case study

Background: Carbamazepine (CBZ) is a BCS II class drug, having many challenges in solubility, flowability, and compactibility. The study focused on the improvement of solubility, flow behavior, and drug release of carbamazepine.

Methods: Low shear granulation (LSG), extrusion spheronization (ES), high shear granulation (HSG), fluid bed granulation (FBG), and hot melt granulation (HMG) methods were employed to prepare CBZ granules. Polyvinylpyrrolidone (PVP) K29/32, PVP K90, and Hydroxypropyl methylcellulose (HPMC) E5 were used as a binder. The drug to binder ratio was maintained in the proportion of 95:5. The nature of granules was analyzed by using X-ray Diffraction and Differential Scanning Calorimetry techniques. A powder flow tester was utilized to study the flow characteristics of the granules.

Results: The HMG has successfully converted the crystalline structure of CBZ granules into an amorphous form. Dispersive and distributive mixing in the HMG has achieved better solid dispersion and fast drug release. The ES technique has reported the incompressible nature of the granules. PVP K90 and HPMC E5 were superior binders for imparting strength to the CBZ granules than PVP K29/32. The FBG has exhibited the free-flowing nature of granules due to their uniform and spherical shape.

Conclusion: The HMG and FBG were the most effective methods that have remarkably improved drug release, flow properties, and compactibility of CBZ granules.