Applications of Alginates in the Design and Preparation of Orodispersible Dosage Forms

Orodispersible dosage forms are attractive and innovative drug delivery systems that can fulfill individual patient needs, especially in children, elderly and among dysphagic patients. Indeed, they rapidly disperse in the mouth upon contact with the saliva without the need for water or munching. Examples of such dosage forms include orodispersible tablets (ODT), and orodispersible films (ODF).

The ability to obtain ODF with different dimensions (sizes and thicknesses) makes them a suitable for personalized dosing of single or a fixed-dose combination of drugs in special patient populations. Several biopolymers are currently being exploited in the development of orodispersible dosage forms including alginates due to their versatility, availability, naturally occurring, and biosafety profile.

This chapter provides an appraisal on the various applications of alginates in the preparations and their role on the properties of orodispersible dosage forms and highlights future perspectives of this very versatile biopolymer for these innovative drug delivery systems.

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Introduction:

Orodispersible dosage forms can ameliorate the lack of compliance associated with the administration of conventional oral solid-dosage forms (i.e., capsules and tablets), or even oral liquid-dosage forms in some patients with swallowing difficulties and hence, have the potential to improve medication adherence [1]. Indeed, since their appearance into the pharmaceutical market, their development has grown gradually, moving from orodispersible tablets (ODT) to orodispersible films (ODF) which presents several advantages to completely eliminate the fear of chocking in some patients [2, 3]. Moreover, pharmaceutical companies have amplified research in these dosage forms because they can easily extend their product portfolio [4].

ODF have the size of a postage stamp and are individually packed so that transportation and patient handling are friendly (Figure 1a). ODF consist of a single or multilayer sheet of suitable materials intended to be place in the mouth where they rapidly dispersed upon contact with the saliva without need of water or munching (Figure 1b). They provide the opportunity to meet the needs of specific subpopulation of patients suffering from a variety of disorders such as dysphagia due to pathological or psychological issues. In addition, children and elderly, and patients with limited access to water and/or restricted water intake can also benefit from their merits [1, 5]. Indeed, the possibility to change size, shape and color of the ODF have open new scenarios to prepare small batches for personalization of dose in special patient population [6]. Furthermore, ODF can be advantageously used as a carrier for other technologies, such as microparticles, nanocrystals and self-emulsifying systems [5, 7, 8, 9], which regulate the drug release patterns and, hence, its bioavailability. However, the main ODF pitfalls are related to the limited formulation space [10] which implies a limited drug loading capacity. Secondly, palatability drives the compliance for ODF loaded formulations, but the formulation space often limits the addition of taste masking agents; even if both bitter and/or astringent taste of a drug can be opportunely reduced and/or eliminated [11, 12]. Thirdly, the manufacturing process at the industrial scale is mainly based on solvent-casting technologies, which require production chains with specialized equipment common only to transdermal patches, and therefore, the number of manufacturers worldwide are limited. Nevertheless, similar to transdermal patches, the dose loaded in an ODF is defined by their size and, therefore, the same production chain could be used to prepare batches of different drug strengths. Because of this peculiarity, researchers are striving to optimize and/or to develop technologies to exploit this peculiarity in the extemporaneous compounding of small batches of ODF in a pharmacy setting [5]. Since the term “customized dosage form” should be related not only to a tailored dose but also to doses on-demand, shape and color of a dosage form [13], this innovation would also allow end-users to easily identify their own medicine, improving medication safety and adherence [5].

ODF are generally made up of plasticized hydrocolloids or blends made thereof that can be laminated by several techniques and sealed in a moisture-protective packages [1]. The active pharmaceutical ingredient (API) can be dissolved or dispersed as such or as nanocrystals [7] or loaded into microparticles [8] depending on the physicochemical properties of the drug and the desired release pattern. Other ODF formulation components are; surfactants, viscosity modifiers, taste-masking agents and coloring agents, when required [5, 14, 15].

Among the critical quality attributes of ODF, satisfactory tensile properties to guarantee packaging and handling during administration without breakage, the disintegration and dissolution in the oral cavity, acceptable taste [5], esthetic appearance, and stability of the dosage form itself and the loaded drug(s) need to be carefully studied. For instance, the choice of taste-masking agents depends not only on the improvement of palatability, but also on their compatibility with other formulation components, the possible impact on the drug’s solubility and dissolution rate, and mechanical properties of the final ODF formulation [5, 12]. This chapter provides an appraisal of the various applications of alginates in the design and preparation of orodispersible dosage forms as new emerging drug delivery systems to overcome some limitations with the conventional solid dosage forms. The literature was generated from the Scopus, and PubMed data bases by searching single or the combination of the following keywords; alginate, alginates, orodispersible film, orodispersible tablet, and orodispersible dosage forms.

Article information: Garba M. Khalid and Francesca Selmin (July 29th 2021). Applications of Alginates in the Design and Preparation of Orodispersible Dosage Forms [Online First], IntechOpen, Available from: https://www.intechopen.com/chapters/77732