EXTRACTION AND CHARACTERIZATION OF CITRIC ACID MODIFIED POTATO STARCH AND ITS USE AS DISINTEGRANT IN METRONIDAZOLE TABLET FORMULATIONS

Products of natural origin are used as active pharmaceutical ingredients and excipients in the production of medicines. Native starches are not effectively utilized in many applications oweing to their lack of ability to survive processing conditions like extreme temperature, variation in pH and its poor flow properties. To overcome these disadvantages, they are modified by physical, chemical, enzymatic, and genetic processes. Potato starch was altered with citric acid, and was used as disintegrant in formulation of metronidazole tablets in this study. Potato starch was separated from pulverized potato tubers using the distilled water method. It was transformed using citric acid (Modified potato starch, (MPS)). MPS was characterized based on flow and physicochemical properties. Microbial count and acute toxicity studies were also carried out. MPS was used and evaluated as disintegrant in metronidazole tablet formulations. The pH and gelatinization temperature of MPS was 4.9±0.0 and 67oC respectively. The bulk density was 0.55±0.01 g/ml, while the tapped density was 0.65±0.02 g/ml. It has a Carr’s index of 15.75±4.34%, Hausner ratio of 1.19±0.06 and angle of repose value of 42.65±0.65o. These indicate poor flow property. The swelling index and loss on drying values of MPS were 86.19±2.34 and 4.17±0.58% respectively.The hardness value for the metronidazole tablets was from 4.08±0.02 to 7.97±0.05 Kgf, whereas the friability was from 0.32 to 6.83%. The disintegration time ranged from 13.09±2.40 to 41.05±3.65 min. The study showed that MPS has enhanced physicochemical properties and could be utilized as a disintegrant in metronidazole tablet formulation.