You don't say if any blinding has been applied.
The MHRA GCP Guide (2012) section 6.12.2 says that you should use a risk based approach. Table 6.5 says that when "IMP and comparator(s) used within their authorisation" then this is "Normal prescribing practice.
No requirement for:
• Shipping receipt and destruction records
• Drug accountability, provided the sample size is acceptable to account for the variability in drug compliance. Alternatively, if the sample size is small, subjects may be asked to complete a diary card or return the remainder of the prescription
• Recording batch numbers and/or expiry dates, unless part of routine practice"

However if blinding is applied then you should look in section 6.13.4