As a general rule, the person is not entitlted to get this certificate. This certificate is only available to under 16s; women who are pregnant or have had a baby in the last 12 months; and people who get benefits (not allowed to anyone on a PSW visa as they count as public funds).
However, there are some exemptions and could be entitled to get free prescriptions if the person has:
• cancer
•a permanent fistula (for example caecostomy, colostomy, laryngostomy or ileostomy) requiring an appliance or continuous surgical dressing
•a form of hypoadrenalism (for example Addison's disease) for which specific substitution therapy is needed
•diabetes insipidus or other forms of hypopituitarism
•diabetes mellitus, except where treatment is by diet alone
•hypoparathyroidism
•myasthenia gravis
•myxoedema (hypothyroidism requiring thyroid hormone replacement)
•epilepsy requiring continuous anticonvulsive therapy
•continuing physical disability that prevents the person from going out without help from another person. Temporary disabilities do not count even if they last for several months
I got the info from:
http://www.nhs.uk/NHSEngland/Healthcost ... costs.aspx
Hope this clarifies your doubt.