i'm not trying to put down your parents, but there are a couple of faulty things about their logic:
1. business and pharmacy are not necessarily easy. pharmacy can be difficult because of all the chemistry involved in it, and business can be difficult because of its competitiveness.
2. although pharmacy is very likely to provide you a secure future (simply because it's healthcare, and healthcare is something that will always be around), business is not. business it very risky since it is closely related to the economic situation of a country (i.e. the fluctuations in the business cycle). one day your business can be booming, and within a few months it can start to die away. just search the internet, and you will find numerous stories of very successful businessmen who end up with little to nothing (or a fraction of what they used to earn). the most recent article i read related to this topic was in the debate section:
http://www.latimes.com/news/printedition/california/la-me-porterranch7-2008oct07,0,7721919.story although this is not the case with all businessmen, the important thing to note is that business does not ensure that you will make money after college.
as far as deciding on a major goes, it's easy for me to say that you should do what you're interested in, but the reality is that it's not that easy to go against what your parents would like for you to do. therefore, i honestly don't know what to tell you except that you should try to compromise with them. maybe you can double major; what about trying to major in political science and pharmacy or business?