Abstract
Spray dried and granulated lactosa was subjected to sieve analysis, and flow rate together with angle of repose also determined. Tablets of lactose were prepared, at pressures of SO 2 and 120 MN/m at production rates from 1 to BO per minute, using an instrumented single punch tablet machine.
The physical properties of the tablets determined were hardness, thickness, uniformity of weight, friability and disintegration time. They were found to conform to United States Pharmacopoeal standards for uniformity of weight and thickness, friability decreased with tablet hardness.
Examination of tablet surfaces, using a scanning electronmicro-scope, revealed differences in structure related to speed of production with smoother more compact surfaces produced as tabletting rate was increased. This was most pronounced at the highest punch pressure and probably is the result of faster consolidation of particles and their surface fusion. A result of this was that disintegration time for tablets, produced at a given pressure, increased in direct proportion to the speed of production. Repose angles in the range of 24–30 had no significant effect on physical properties of tablets and whatever the rate of production die fill and consequently tablet weight did not vary.
Rate of tablet production can. as shown here, influence their physical properties with those produced at higher rates having increased disintegration tiaws and probably less satisfactory dissolution characteristics.