Current Drug Delivery, 2009, 6, 469-476 469 1567-2018/09 $55.00+.00 © 2009 Bentham Science Publishers Ltd. A Review on Mouth Dissolving Films Meenu Dahiya, Sumit Saha and Aliasgar F. Shahiwala* National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, C/o. B.V. Patel Pharmaceutical Education and Research Development Centre, S.G. Highway, Thaltej, Ahmedabad-380054, India Abstract: The ultimate goal of any drug delivery system is the successful delivery of the drug to the body; however, pa- tient compliance must not be overlooked. Fast dissolving drug delivery systems, such as, Mouth Dissolving Films (MDF), offer a convenient way of dosing medications, not only to special population groups with swallowing difficulties such as children and the elderly, but also to the general population. MDF are the novel dosage forms that disintegrate and dissolve within the oral cavity. Intra-oral absorption permits rapid onset of action and helps by-pass first-pass effects, thereby re- ducing the unit dose required to produce desired therapeutic effect. The present review provides an overview of various polymers that can be employed in the manufacture of MDF and highlights the effect of polymers and plasticizers on vari- ous physico-mechanical properties of MDF. It further gives a brief account of formulation of MDF and problems faced during its manufacture. Keywords: Mouth dissolving films, intraoral, film forming polymers, glass transition temperature, tensile strength, blooming. INTRODUCTION Oral route is most preferred and patient-convenient means of drug administration. Most of the drugs are being taken in the form of tablets and capsules by almost all pa- tients, including adult, paediatric and geriatric patients. However, around 26 – 50% of patients find it difficult to swallow tablets and hard gelatin capsules [1]. These patients mainly include, elderly (who have difficulties taking conven- tional oral dosage forms because of hand tremors and dysphagia), paediatric patients (who are often fearful of tak- ing solid oral dosage forms, owing to their underdeveloped muscular and nervous systems) [2] and others which include the mentally ill, developmentally disabled, patients who are uncooperative, on reduced liquid-intake plans or nauseated, and travellers who may not have access to water [3, 4]. In addition, the relatively poor absorption, presence of abundant digestive enzymes in the GI lumen and epithelium, post- absorption efflux (i.e., by P-glycoprotein, etc.), and first-pass metabolism by the hepatic enzymes and subsequent elimina- tion, limit the ability of many drugs to reach therapeutic lev- els by oral route [5]. Moreover, a tablet (most common dos- age form for this route) has to disintegrate in the gastrointes- tinal tract followed by dissolution of the drug. These proc- esses extend the time until efficacy to some extent, which is undesirable in conditions, such as pain [5]. Transmucosal routes of drug delivery (i.e., the mucosal linings of the nasal, rectal, vaginal, ocular, and oral cavity) offer distinct advantages over oral administration for sys- temic drug delivery. These advantages include possible by- pass of first pass effect, avoidance of pre-systemic elimina- tion within the GI tract, and, low enzyme activity. The nasal *Address correspondence to this author at the National Institute of Pharma- ceutical Education and Research (NIPER)-Ahmedabad, C/o. B.V. Patel Pharmaceutical Education and Research Development Centre, S.G. High- way, Thaltej, Ahmedabad-380054, India; Tel: +91-79-27439375, 27416409; Fax: +91-79-27450449; E-mail: alishahiwala@gmail.com administration of drugs, including numerous compound, pep- tide and protein drugs, for systemic medication has been widely investigated in recent years. However, the potential irritation and the irreversible damage to the ciliary action of the nasal cavity from chronic application of nasal dosage forms, as well as the large intra- and inter-subject variability in mucus secretion in the nasal mucosa, significantly affects drug absorption from this site. Even though the rectal, vagi- nal, and ocular mucosa offer certain advantages, the poor patient acceptability associated with these sites renders them reserved for local applications rather than systemic drug ad- ministration [6]. As a site for drug delivery, oral cavity (intraoral route) offers advantages over the conventional gastrointestinal route and the parenteral and other mucosal routes of drug administration. It provides direct entry into the systemic cir- culation thereby avoiding the hepatic first pass effect, ease of administration and the ability to terminate delivery when required [7]. Intraoral drug delivery has become an important route of drug administration. Various intraoral dosage forms have been developed, which includes adhesive tablets, gels, ointments, patches, fast-dissolving drug delivery systems (FDDDS). A fast-dissolving drug delivery system (FDDDS) is the most convenient mode of administering drugs to over- come problems related to swallowing difficulties. These de- livery systems dissolve or disintegrate in the mouth rapidly, without requiring any water to aid in swallowing [8]. Disso- lution within oral cavity also permits intra-oral absorption, thus bypassing first-pass effects. FDDDS offer advantages such as disintegration without water, rapid onset of action, ease of transportability, ease of handling, pleasant taste, and improved patient compliance. Fast dissolving drug delivery was pioneered by scientists at Wyeth Laboratories in the UK during the late 1970s, which resulted in patenting of the "Zydis" drug delivery system [9]. Most fast dissolving drug delivery systems are in a tablet form [8]. WOWTAB, Zydis, Orasolv and Shearform are some of fast dissolving technolo-