Tablets are solid unit dosage form of medicaments with or without suitable diluents and prepared either by molding or compression. They are solid, flat or biconvex disc in shape. They vary greatly in shape, size and weight which depend upon amount of medicament used and mode of administration. They also vary in hardness, thickness, disintegration and dissolution characteristics and in other aspects depending upon their intended use and method of manufacture. Tablets are the most widely used solid dosage form of medicament. Because of their advantages their popularity is continuously increasing day by day. Hypertension is a very common disorder, particularly past middle age. It is not a disease in itself, but it is an important risk factor for cardiovascular mortality and morbidity. The WHO-ISH guidelines defined it to 140 mm Hg systolic and 90 mm Hg diastolic, through risk appears to increase even above 120/90 mm Hg.

Patients who have problems in swallowing encounter difficulties in taking tablets, particularly pediatric and geriatric patients. Such problems can be resolved by means of orodispersible tablets. These tablets disintegrate instantaneously when put on tongue, releasing the drug that dissolves or disperses in the saliva.Metronidazole is active against a wide variety of anaerobic protozoal parasites and anaerobic bacteria.The present study aim to prepare tablets that can rapidly disintegrate in oral cavity (orodispersible), another challenge with this model drug is to mask the bitter taste. Taste masking was achieved by using aminoalkyl methacrylate copolymer (Eudragit E-100) in the different ratio (1:2 and 1:3) by extrusion technique. The IR shows that there was no significant evidence for interaction between drug and polymers. Six formulations were prepared using taste masked granules and different disintegrants (LH-11) and Avicel PH-102 by varying concentration.