Design and preparation of a novel pullulan hard capsule formulation: A promising green candidate and study of crucial capsule features

Plant-based hard capsules have gained considerable attention because of their great properties. Accordingly, designing and developing of these kinds of capsules will be a difficult task. Herein, an innovative pullulan-based hard capsule formulation was prepared for the first time. A series of characterization approaches, including Fourier transform infrared, field emission scanning electron microscope, and rheology analysis, were utilized to figure out the straightforward preparation of a designed hard capsule. Many tests and experiments were performed to achieve the optimum capsule formulation. Based on the obtained results, specifications such as uniform downfall and non-desirable adhesion, and other ideal characteristics of the capsule display the critical function. The gelling promoter of divalent cationic salts is more beneficial than its single-valent counterparts. With respect to the key role of gelling promoter, the presence of chosen MgSO