Background: Sugar substitutes are used by diabetic, obese and calorie-conscious people. As artificial sweeteners are harmful to the body, natural sweeteners are more suitable. Sugar substitutes are available on the market in tablet forms, which are added to hot or cold drinks. Rapid disintegration and dissolution of sugar substitute-loaded tablet is desired. However, the tablets should be hard enough to maintain their integrity during mechanical shocks.
Objectives: The objective of this research was to develop rapidly disintegrating and dissolving stevia-loaded tablets with appropriate wetting, hardness and friability.
Material and methods: Several tablets were prepared using different superdisintegrants using the direct compression method. Flowability tests of the powder blends were performed before compression; these test took into account such physical parameters as bulk density, tapped density, angle of repose, compressibility index, and Hausner's ratio. Evaluation of the compressed cores was accomplished with weight variation, hardness, thickness, friability, disintegration time, wetting time, and dissolution.
Results: The disintegration time and wetting time of the tablets were in the following order: sodium starch glycolate > croscarmellose sodium > crospovidone containing tablets. A powder blend consisting of stevia extract, crospovidone, lactose, and magnesium stearate at the optimized ratio of 15/2.5/32/0.5 (w/w/w/w) showed the best flow, rapid disintegration (38 ±0.894 s), wetting (30 ±1 s), and dissolution (~ 95% in 1 min). Moreover, this formulation showed more rapid wetting (30 ±1 s vs 91 ±1.9 s), disintegration (38 ±0.894 s vs 143 ±1.276 s) and dissolution (~ 95% vs 60% in 1 min) than a commercial product.
Conclusions: The tablet consisting of stevia, crospovidone, lactose, and magnesium stearate at the weight ratio of 15/2.5/32/0.5 showed excellent results with regards to dissolution and disintegration; accordingly, this formulation could be a potential sugar substitute for diabetic, obese and/or calorie-conscious individuals.
Keywords: hydrophilic polymers; sugar substitute; superdisintegrants; wetting time.