Formulation Development and Evaluation of Mouth Dissolving Tablet of Tramadol Hydrochloride

Many patient groups, such as the elderly, children, mentally retarded, uncooperative or nauseated, have difficulty in swallowing conventional dosage forms, like tablets. Swallowing conventional tablets will be further hindered by conditions such as unavailability of water, allergic reactions and episodes of coughing1. These problems can be solved by developing rapidly disintegrating and dissolving tablet dosage forms for oral administration, because they dissolve in saliva and does not require water for swallowing. Upon ingestion, the saliva serves to rapidly dissolve the dosage form. The saliva containing the dissolved or dispersed medicament is then swallowed and the drug is absorbed in the normal way. Some drugs are absorbed from the mouth, pharynx and oesophagus, as the saliva passes down in to the stomach. In these cases, the bioavailability of drugs is significantly greater than those observed from conventional dosage forms2. The bioavailability of some drugs may be increased due to absorption of drugs in oral cavity and also due to pregastric absorption of saliva containing dispersed drugs that pass down into the stomach. Moreover, the amount of drug that is subjected to first pass metabolism is reduced as compared to standard tablets3. A wide range of drugs requiring quick onset of action are the promising candidates for this dosage form. These include neuroleptics, antidepressants, cardiovascular drugs, analgesics and so on. Fast dissolving tablets (FDTs) can be prepared by different methods, such as direct compression, freeze-drying, spray drying, sublimation, wet granulation method4. The basic approach for the development of FDTs is the use of superdisintegrants. The aim of this study was to formulate FDTs with sufficient mechanical integrity and to achieve faster disintegration in the oral cavity without water. To achieve this goal, mannitol used as diluent and aspartame as sweetening agent for the formulation of tablets. Attempts were made to enhance dissolution rate along with faster disintegration using superdisintegrants, like croscarmellose sodium, sodium starch glycolate and crospovidone. Tramadol hydrochloride, a centrally acting synthetic opioid analgesic, was selected as the active pharmaceutical ingredient in the study.