Fast-Melting Tablets: Developments and Technologies

www.pharmtech.com any patients have difficulty swallowing tablets and hard gelatin capsules and consequently do not take medications as prescribed. It is estimated that 50% of the population is affected by this problem, which results in a high incidence of noncompliance and ineffective therapy (1). The demand for solid dosage forms that can be dissolved and suspended in water, chewed, or rapidly dissolved in the mouth is particularly strong in the paediatric and geriatric markets, with further application to other patients who prefer the convenience of a readily administered dosage form. Because of the increase in the average human life span and the decline, with age, in swallowing ability, oral tablet administration to patients is a significant problem and has become the object of public attention (2,3). The problem can be resolved by the creation of rapidly dispersing or dissolving oral forms, which do not require water to aid swallowing. The dosage forms are placed in the mouth, allowed to disperse or dissolve in the saliva, and then are swallowed in the normal way. Less frequently, they are designed to be absorbed through the buccal and oesophageal mucosa as the saliva passes into the stomach. In the latter case, the bioavailability of a drug from fastdispersing formulations may be even greater than that observed for standard dosage forms. Furthermore, side effects may be reduced if they are caused by firstpass metabolites (1,4). Fast-dispersing formulations, commonly called fast-melting tablets (FMTs), also offer advantages over other dosage forms such as effervescent tablets, extemporary suspensions, chewing gum, or chewable tablets, which are commonly used to enhance patient compliance. Effervescent tablets and extemporary suspensions require preparatory steps before administration of the drug. The elderly, who often are unable to chew large pieces of gum or tablets, sometimes experience unpleasant taste problems when bitter drugs are present. In this case, the bitterness of the chewable tablets markedly increases because of the prolonged time that they are in the mouth or as a result of leaching of the drug from chewed or broken microcapsules. The advantages of FMTs increasingly are being recognized in both industry and academia. Their growing importance was underlined recently when the European Pharmacopoeia adopted the term orodispersible tablet as a “tablet to be placed in the mouth where it disperses rapidly before swallowing” (5).