Spellbound

Normal sudoku rules apply.

A digit in a yellow circle (or a two digit number in a yellow pill, reading left to right) is spelled out in English using the number of letters indicated by the digit in the circle it is pointing at, or by the two digit number if it is pointing at a pill.

Eg: TWENTY FIVE is spelled with 10 letters, so a 25 pill would need to point at a 10 pill. (This example would be problematic as no zeroes are allowed in this puzzle!)