I want to study MSc in pharmaceutical sciences in the UK with the maximum possible scholarship.. what are the chances that I can get a minimum of 70% scholarship?

Hey, there are a couple of scholarships available to pursue Master's in the USA. Here is a list of the top scholarships -

Stanford University Scholarships -

Stanford University Scholarship is a fully funded scholarship for international students. This scholarship is offered for Masters. This scholarship is offering a full traveling allowance, academic expenses, tuition fees, and a living allowance. 

Onsi Sawiris Scholarship -

Onsi Sawiris Scholarship program is a fully-funded master's scholarship for international students. The scholarship covers living allowances as well as travel and health insurance. 

Yale University Scholarship USA - 
Yale University Scholarship is a fully funded scholarship awarded to international students. This scholarship is offered to students pursuing master's. It can vary from a few hundred dollars to over $70,000 per year. 

Global Study Awards -
This scholarship arrived in 2015 and is an initiative by the British Council. It offers scholarships of  USD 11,900. If the tuition fees are lower, the remainder will be given for a maximum of 52 weeks’ living costs. 

I hope this helps. Let me know if you have any other questions.