## 1 Introduction  
Drug production technology in the 21 st century tends to be personalized [1, 2] to reduce the risk of adverse drug reactions and to optimize therapeutic efficiency; accordingly, two-dimensional (2D) printing technology has been adapted to manufacture orodispersible films. This is because 2D printing can digitally deposit a very small amount of drug (ink) on a substrate (edible carrier) [3]. Among several 2D printing techniques, inkjet printing has been applied for manufacturing drug-loaded films due to its feasibility and the high precision/accuracy of the deposited ink volume. Therefore, inkjet printing technology is a suitable method for film preparation prior to loading high-potency and/or narrow therapeutic index drugs [4, 5]. Two-dimensional printing techniques are also precise methods that could be implemented in a hospital setting in the future for the preparation of personalized doses [6]. Ink (drug solution/suspension) properties, including viscosity, surface tension, boiling temperature, and solvent evaporation rate, play a vital role in the quality of the printing process [7]. Moreover, flexible and highly absorbent properties are required to effectively print substrates. Therefore, optimizing the formulation of both ink and substrate are necessary to ensure optimum orodispersible film properties. Orodispersible films are drug-loaded single or multilayer edible sheets that can rapidly dissolve in the mouth. These films can be administered through mastication and water intake because they dissolve in saliva. Orodispersible films are suitable for older adults who generally face problems with psychological dysphagia [8]. Furthermore, they can be administered to both pediatric and psychiatric patients [9]. Orodispersible films can also enhance drug dissolution and absorption owing to drug dispersion throughout the film former [10]. Several methods, such as solvent casting [11], electrospinning [12], and hot-melt extrusion [13], have been applied in the preparation of orodispersible films. However, dose adjustment is a limitation when using orodispersible films prepared using more conventional methods. Thus, inkjet-printing technology has been introduced in order to accurately print adjustable drugs on a film substrate [6]. Two-dimensional printing requires the use of an edible carrier (substrate) that would absorb the deposited ink. HPMC [14], PVA [15], potato starch [4], and rice starch [16] have been used as the substrate for the inkjet drug printing. Most of the substrate polymer has to combine to decrease the contact angle between the ink and the substrate, and enhance the flexibility of the film [17]. In this study, the novel substrate for inkjet printing, which was gum from _Tamarindus indica_ seeds, has been introduced due to its hydrophilic and high Young's modulus properties [18]. Due to the numerous advantages of 2D printing, there are groups of studies beginning to apply 2D printing in drug formulation. As an example, [PERSON] et al. used inkjet printing to increase the solubility of a poorly soluble molecule, namely relodipine, with an excipient, namely PVP, to enhance the dispersion property of the controlled release solid dosage form [19]. Additionally, the fabrication of nanoparticle complexes between the BCS class II drugs and the polysaccharide before printing on the substrate provides an abundant scope for progressing the dissolution property of some poorly water-soluble drugs [20]. Inkjet printing is also suitable for low-dose drug formulation. [PERSON] et al. showed the application of a simple, home, inkjet printer to print salbutamol films on a paper tray of the printer, which was then modified to print the highest resolution and highest quality drug, provided that the printed templates were designed by Microsoft Word software [4]. From previous studies of a 2D printing application for drug formulation preparation, it could be proven that the drug can be prepared by an inkjet printer. However, the low drug loading is a limitation of this technique.