Assuming that you are in the correct type of running shoe (stability / motion control) already, then the typical solution is an orthodic. This will provide additional support and/or cushioning and better distribute load across the foot, i.e. the assumption being that a disproportionate amount of load is going through your big toe. Whether that'll end up being a relatively inexpensive off-the shelf product or a $300 custom orthodic is another matter. Many folks have success with the former after a little googling and a visit to their local running speciality store. However; a visit to the podiatrist is always good idea where you should receive an expert assessment and appropriate solution.