We recommend one pack per distillation.
Under certain circumstances, you could technically use the same botanicals again, but the flavour won't be as good with a chance that there will be more burnt vegetable/botanical notes.
Most of the oils would have been extracted from the first run so there will be little to no use in them after this.
Also, if it had fine powders, you would notice it would have gone clumpy/pasty. Therefore, it's best to use one pack per distillation.