Question Summary:
Placing a condition of capital return

Question Detail:

 
assalamoalykum
I invested my money with my friend in a business, he told me that we will divide the profit amongst. He also promised that the amount you are investing will be given to me within 18 months and after that we'll look towards the profit and loss.Is the condition of taking the invested money back within 18 months is permissible according to islamic view.

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
The agreement in reference is a Mudharabah agreement. 
Mudharabah is a business partnership wherein one partner contributes his capital to the partnership while the other partner manages the capital
In a Mudarabah partnership, a fixed profit ratio/percentage may be fixed. For example, partner A receives 60% of the profits while partner B receives 40% of the profits. However, a fixed amount cannot be fixed nor can a percentage be based on the capital investment. You may refer to the following link for a Shariah Compliant Mudharabah contract, http://daruliftaa.net/index.php/resources/publications/finish/27-publications/277-mudarabah-agreement-2
And Allah Ta’āla Knows Best
Huzaifah Deedat
Student Darul Iftaa
Lusaka, Zambia 
Checked and Approved by,
Mufti Ebrahim Desai.
______________
Introduction to Islamic Finance- Mufti Taqi D.B-Page 32
فقه البيوع-مفتي تقي صاحب -جلد 2-ص633-مكتبة معارف القرأن