In general most of the pharmaceutical companies have a Material Transfer agreement (MTS) for sharing the chemical entities for the nonprofit research purpose. I think the manufacture of Cilostazol is Otsuka Pharmaceutical Just you contact them through email or LinkedIn. They will get back to you with relevant documents.

By the way only I got a gift sample form Eli Lilly, USA for my PhD thesis purpose

Good luck

Thanks sir

If any informationplease share 

you can send a letter to plant head of those company who manufacture this drug and you must forward this letter through your research guide, and request the plant head to send required amount of drug through courier .