Context: Starch obtained from different botanical sources exhibit different characteristics due to variation in amylase-amylopectin ratio, which results in different binder substrate interactions.
Objective: The present study characterized Echinochloa colona (L.) Link (Poaceae) starch and evaluated its compressional characteristics for use as tablet excipient against commonly used maize, sorghum, and cassava starch.
Materials and methods: Three experimental design studies were performed to determine the effects of the maize starch and povidone on physical properties of paracetamol (250 mg) tablets. The effect of superdisintegrants sodium starch glycolate and croscarmellose sodium on the optimized composition obtained in the preceding experiments was evaluated in two factorial experimental studies. The maize starch in the optimum formulations was replaced with difra, sorghum, and cassava starch, and tablets prepared from these starches were compared for their compressional characteristics, lubrication sensitivity, moisture uptake, and drug release.
Results: Tablets prepared from maize starch and povidone (30:9, w/w) blend which was previously mixed for 8 min disintegrated (DT) in 10 min. Superdisintegrants decreased DT of tablets significantly (p < 0.05) to 2.2 min. The Hausner ratios of co-processed mixtures containing sorghum, maize, and difra starch were 1.19, 1.21, and 1.26, respectively, with equilibrium moisture content of 8-9%. The DT of sorghum and difra starch formulations which related directly to their higher hydration capacity (difra > sorghum > maize starch) and swelling property was 1.5 min and 2.5 min, respectively, with a friability of 0.32%. The effect of lubrication on the DT and friability of tablets containing maize and difra starch was significant (p < 0.05). However, more than 90% drug was released in vitro dissolution studies.
Conclusion: Difra starch can replace maize and sorghum starch as tablet excipient.
Keywords: Disintegration time; hydration capacity; lubrication sensitivity; swelling capacity; tablet compression; tensile strength; wet granulation.