Recent Formulation Advances and Therapeutic Usefulness of Orally Disintegrating Tablets (ODTs)

Oral Dosage Excipient — Excipient for Oral Dosage

Orally disintegrating or orally dispersible tablets (ODTs) are dosage forms that disintegrate or dissolve rapidly on contact with saliva. Certain ODTs that are formulated for sustained or controlled release have the ODT attribute of rapid disintegration but do not always undergo rapid dissolution. The Center for Drug Evaluation and Research (CDER), a part of the US Food and Drug Administration (FDA), has defined an ODT as a “a solid dosage form containing medicinal substances which disintegrates rapidly, usually within a matter of seconds, when placed upon the tongue”. Two key characteristics that a dosage form labelled as an ODT must possess is a rapid disintegration time of 30 s or less, and a tablet weight of 500 mg or less [1]. In the guidance for industry document “Size, Shape, and Other Physical Attributed of Generic Tablets and Capsules” published by CDER, US FDA, it is recommended that drug manufacturers develop quality target product profiles (QTPPs) for drug candidates. For ODTs, parameters such as disintegration time and tablet size are key components of QTPPs. ODTs are also different from chewable tablets in that they eliminate the need for chewing or drinking liquids. Liquefaction of the ODT occurs on the tongue, followed by the patient swallowing the liquid. Drug release from an ODT is composed of a sequence of events or processes which include initial tablet disintegration, followed by drug dissolution and subsequent drug absorption. Also, unlike effervescent tablets they do not need require the extra step by the patient or the care giver to be dropped into a glass of water prior to administration. Sublingual tablets (placed under the tongue) and buccal tablets (placed in the side of the cheek or high up between the inside and of the upper lip and gum) are also sometimes classified as ODTs.

Abstract
This review highlights the recent formulation advances (different methods of preparation involving various novel approaches) that have been advancing the use of ODT as a popular dosage form. Furthermore, the important characteristics of ODTs that are required for patient compliance and appropriate therapeutic benefit are discussed. In addition to conventional ODTs, ODTs formulated for controlled release of pharmaceuticals and taste masking are also discussed.