BINDING EFFECTS OF TWO BRANDS OF PREGELATINISED STARCH ON ACETAMINOPHEN TABLETS IN A WET GRANULATION PROCESS

The purpose of this work was to study the binding effects of some brands of modified starch. After a pre-formulation study Evansgel® powder and Evansgel® flakes obtained from maize cultivated in Nigeria were used at 2.91, 3.64, 4.55 and 5.69%w/w to formulate acetaminophen (APAP), a high dose, low water soluble drug and the physicochemical properties of the granules and tablets were compared to formulations using commercially available modified and unmodified starch as well as a synthetic binder prepared under the same experimental conditions. Granule flow characteristics, tablet weight uniformity, hardness, friability, disintegration and dissolution rate as well as the dissolution similarity factor, f2 matrics were evaluated. The results showed that the granule size grew with increase in the concentration of the binder irrespective of the binder used. Tablets that met prescribed standards were produced at 4.55% binder with the same physical characteristics across the batches. The drug release rates were well above 90% except the APAP tablets containing polyvinylpyrrolidone, which was less than 50%. All the APAP tablets except those made with PVP had f2 over 80 at 4.55%w/w binder. This work showed that at equal concentration these brands of pregelatinized starch have comparable binding effects to commercially available pregelatinzed starch on acetaminophen tablets prepared by wet granulation method.