Band 5 would be classed as a senior position for a pharmacy tech, albeit not that senior. Make sure you are fully aware of your trust/depts SOPs, things such as labelling guidelines and special expiry dates (i.e packing down). For a Band 5 I would assume you have either completed or will be undertaking training to be qualified as a Accredited Checking Technician.
It can be quite varied because one hospital/trust band 5 position may have different job responsibilities than another. For instance I am a Band 5 Clinical Trials/Named Patient Tech, although I have some specific dispensary duties my speciality is in trials. If you were dispensary based I would assume checking, POD screening and possibly a responsibility to train new staff members.