ABSTRACT
Aims: To evaluate the effect of mucilages of natural and pregelatinized forms of trifoliate yams, rice and official corn starch binders on a paracetamol tablet formulation. Methodology: Natural starches from two trifoliate yam varieties, and rice were isolated and pregelatinized. Both starch forms were then incorporated into a paracetamol tablet formulation as binders. The influence of the binders on compaction of granules and quality of tablets was assessed. Particle, bulk and tapped densities were measured for all the batches of the prepared paracetamol granules. The Heckel and Kawakita plots from which mean yield pressure, Py and another pressure term Pk, which indicates the pressure required to reduce the volume of the granule bed by 50%, were derived respectively. Both were employed to assess the compaction behaviour of the granules. Quality of the compressed tablets was studied using tensile strength, friability, disintegration time and dissolution properties as evaluation parameters. Results: Pregelatinized starch mucilages generally show lower values of both Py and Pk than natural starch mucilages. Increased concentration of starch mucilage binder also yielded lower values of both Py and Pk. Tablets containing natural starches exhibited higher Tensile strength and lower friability than those formulated with pregelatinized starch binders. Generally, Disintegration time (Dt) and the time taken for 80 % paracetamol to be released (t80) were higher for formulations containing natural starch binders than those containing pregelatinized binders The drug dissolution rate constants k1 and k2, were higher for formulations containing pregelatinized binders. Conclusion: The results obtained are suggestive of the fact that the use of mucilage of pregelatinized starch (rather than natural starch), as well as increase in concentration of the material, would yield formulations with faster onset of plastic deformation as well as higher total plastic deformation. The experimental starches compared well with the standard official corn starch and may thus be developed as substitutes in some tablet formulations.
ABSTRACT
Natural and pregelatinized starches from white and yellow trifoliate yams and rice were comparatively studied with official corn starch, in a paracetamol tablet formulation to assess their relative effectiveness as disintegrants. Disintegration time (Dt) and the (crushing strength/friability)/disintegration time ratio (Cs/Fr)/Dt were employed as assessment parameters. Generally, the rankings of (Cs/Fr)/Dt for the natural and pregelatinized starch disintegrants were white T. yam > corn > yellow T. yam > rice; and white T. yam > yellow T. yam > corn > rice, respectively. Pregelatinized starches produced better combined disintegrant properties of (Cs/Fr)/Dt than natural starches. Tablets formulated with official corn starch disintegrant exhibited the lowest disintegration time values, but generally all the tablets containing the experimental starches also passed the official disintegration time test, and can therefore be used as alternative disintegrants in tablets.