Background: Botanical materials are gaining attention worldwide. As tablet is well recognised for compactness and ease of administration, there is an increasing effort to transform botanical materials into tablet. Tableting of coarse milled botanical materials poses a challenge due to poor tableting properties.

Aim: This study aimed 1) to evaluate feasibility of using wet granulation as a pre-processing step to produce botanical material based tablets and 2) to assess effect of formulation on properties of the tablets.

Methods: Cinnamon bark and areca nut were used as a model botanical materials from bark and nut origin, respectively. The cinnamon and areca were milled to obtain particle size of 1 to 2 mm which was subsequently used in wet granulation using maltodextrin solution as a granulating liquid. Two different diluents were used in the granulation; microcrystalline cellulose (MCC) and mannitol. The granules were prepared from different ratios of botanical material to diluent (1:1, 1:2 and 2:1). Tablets were formed using the granules at three different compression pressures (88, 132 and 176 MPa) and evaluated for tensile strength as well as surface roughness.

Results: Generally, tablets formulated with MCC had higher tensile strength than tablets formulated with mannitol across all compression pressures. Additionally, granules formed from mannitol were more friable than MCC based granules. Effect of diluent to botanical material ratio was more prominently observed on tablet surface roughness. Tablets containing higher ratio of botanical material had rougher surface which could have implication on mouth-feel of the tablets.

Conclusion: The results demonstrated wet granulation as a viable pre-processing method to produce botanical material based tablets. Additionally, type of diluents and ratio of diluent to botanical materials could affect physical properties of the tablets.

Keywords: botanical material, tablet, wet granulation, milling