As Sam Walton said, 'One store at a time'. If you have fixed one then it is time to acquire another. Each acquisition gets easier than the previous one. Before long you could have the largest independent chain in the country!
One thing to note, though: you will also need to undergo a personal cultural change in order to grow your business. You must let go of your daily operational functions when you grow bigger. Be a captain of a ship and don't spend time working below in the engine room. Spend time working on business strategy and developing people. Set yourself key performance indicators for sales €“ both Rx and OTC €“ as well as cost control, and manage by exceptions.
Importantly, learn to manage people and let people manage your business. Be as dynamic as your business and sharpen up your own skills.