[Zoggite]

This is the only reference I could find, it's from the PSNC's "dispensing Resources" booklet, page 35:
"Sugar Free Medicines
The Code of Ethics states that 'Except in an
emergency, pharmacists must not substitute
any other product for a specifically named
product without the approval of the patient or
carer and the prescriber' and under the NHS
Terms of Service, a chemist is required to
supply the drugs ordered with reasonable
promptness.
The RPSGB have confirmed that when a
prescriber does not specify 'sugar free' and a
pharmacist supplies a sugar free medicine
then this would not be in breach of the Code
of Ethics.
However if a sugar free formulation has been
prescribed, then the pharmacist should supply
this, other than in exceptional circumstances.
The exception to this would be when a
Schedule 2 and 3 Controlled Drug has been
prescribed, as the Code of Ethics Service
Specification 19 (Services to Drug Misusers)
states that a pharmacist must not deviate from
the instructions given on the prescription and
sugar free/colour-free preparation must not be
dispensed unless specifically prescribed.Pharmacists should endorse the prescription
appropriately. The pharmacy will be
reimbursed based on the prescribed product
with the normal reimbursement rules applied."

Is that any help? it's probably one of those situations again where it's not illegal to supply non-SF methadone, but it's considered to be "best practice" to do so, rather than let the patient go without altogether? "Patient's best interest", etc...etc...