Is zakat obligatory on a sum of money invested in establishing a private hospital, given that the hospital has begun operations but is not expected to yield profits for 3 years due to loan repayments?

If the intention behind participating in the hospital is to benefit from the profit, then there is no zakat on the principal capital. Rather, zakat becomes obligatory on the profits after they reach the nisab (minimum threshold) and a hawl (full lunar year) passes over them. However, if the contribution is for the purpose of trading shares and selling them, then zakat is obligatory on the shares every year if they reach the nisab, and the amount of zakat is a quarter of a tenth (2.5%).