**2. Preparation methods orodispersible dosage forms**

Orodispersible dosage forms can be broadly divided into two based on their current commercial availability, i.e., orodispersible tablet (ODT) and orodispersible films (ODF). Each of them requires a specialized type of equipment, polymers and other formulation additives or excipients since they both have some similarity and distinctive peculiarities. The market penetration and commercial success of either ODT or ODF depends on the taste of the finished product since the palatability of the drug product in orodispersible dosage forms determines patient acceptability and subsequently therapeutic success of drug loaded. Therefore, different taste masking strategies are employed to mask unpleasant tastes or odors of drugs in orodispersible dosage forms such as the use of microencapsulation, complexation technique, using taste masking agents such as sweeteners and flavoring agents [3, 14].

Orodispersible tablets (ODT) have the same appearance with the conventional tablets. However, unlike the conventional tablets, they are expected to rapidly disintegrate within 3 min as a result of their high porous network with the rapid penetration of water and/or other fluids. They can be prepared by direct compression, heat molding technique, or freeze-drying using specific excipients such as alginates (**Table 1**) or their particle engineering products [3].

Orodispersible films (ODF) are mainly prepared by solvent casting technology, electrospinning, hot-melt extrusion and more recently by various printing techniques for dose personalization [3, 5]. In some cases, a combination of these methods is used to obtain an ODF with desired properties or to achieve the desired technological and therapeutic objectives. For instance, various printing technologies have been coupled with other ODF preparation techniques such as solvent casting and fused deposition modeling (FDM) 3D printing to prepared ODF on-demand. Moreover, hot-melt extrusion (HME) is a solvent-free, continuous process. It has a short processing time, suitable for small-scale on-demand preparation of medicines, and is easy to scale-up. Several thermoplastic polymer-carriers and other additives used during extrusion processing are generally regarded to be safe for human consumption [28]. Over the last two decades, HME has been employed as a novel cost-effective pharmaceutical manufacturing technique of different oral solid-dosage forms. It has been suitably used in the preparation of immediate-release, novel taste-masked and abuse deterrence tablets formulations [28, 29], chrono-modulated drug delivery systems [30], for immediate release formulation of ODF [2, 3], and ODF containing poorly water soluble and highly polymorphic drugs [31–33]. Thus, the combination of HME and additive printing technology has been shown to offer several advantages [6, 33]; first, the ability to fabricate immediate-release, modified-release, and other novel drug delivery dosage forms, second, the ease to prepare personalized oral drug delivery products,


#### *Properties and Applications of Alginates*

