Evaluation of the Binding Properties of a Polymer Obtained from Modification of Triticum aestivum Starch in Metronidazole Tablets Formulation

Aim: The binding properties of a polymer obtained from modification of Triticum aestivum (TA) starch in metronidazole tablets formulation were evaluated.

Study Design: Experimental design.

Place and Duration of Study: Department of Pharmaceutics and Pharmaceutical Technology, University of Port Harcourt, Choba, Rivers State, Nigeria from January to July, 2018.

Methods: TA seeds were steeped for 72 h, wet milled and the native Triticum aestivum starch (NTS) extracted. NTS (1kg) was oxidized by slurring in 4 L of 3.50% w/v sodium hypochlorite, washed to neutral pH with 95% v/v ethanol (MTS). MTS was dried at 60°C for 3 h, milled and classified (250 μm). The starches were characterized using standard methods and applied as binders at 1, 2 and 3% w/w in formulating metronidazole tablets using wet granulation. Methylcellulose and gelatin at similar concentrations were used as standards.

Results: The granules and tablets were evaluated using standard methods. NTS and MTS had similar properties with starch. The modification improved the densities, hydration capacity and flow properties of MTS. The granules flowed and compressed well. The tablets had minimal weight variation, hardness (≥ 4 kgF), friability (<1%) and disintegration (<15 min). Metronidazole release (≥ 85%) within 60 min existed in all the batches except batches containing 1% methylcellulose and 3% gelatine.

Conclusion: The results met with United States Pharmacopoeia specifications for oral uncoated metronidazole tablets. MTS performed better than NTS and compared well with methylcellulose and gelatin as binder in metronidazole tablet formulation.