If you are reviewing products (which you purchase - not given as freebies) then absolutely they are a business expense.
It is what you do with it after that review. Do you sell it on, give it to a customer as a gift or keep it yourself?
Claiming items like this as a business expense is not a problem but you may find that your P11D and Self Assessment forms start to become more complicated if you start using business purchases personally.
As you are LTD and making a profit are you paying dividends? Can you take on an employee?