Postal address:
WHO Collaborating Centre for Drug Statistics Methodology
Norwegian Institute of Public Health
Postboks 222 Sk°yen
0213 Oslo

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Sandakerveien 24C
Bygg C
0473 Oslo

Tel:  +47 21 07 81 60

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A formulation approved both for use in the eye/ear is classified in S03. Formulations approved for eye, ear and nose are also classified in S03. Formulations only licensed for use in the eye or the ear are classified in S01 and S02, respectively.


Most of the drugs in this group are topical preparations. Systemic preparations with clear ophthalmological indications are also classified in this group.
Small amounts of antiseptics in eye preparations do not influence the classification, e.g. benzalconium.
See also S03 - Ophthalmological and otological preparations.

DDDs have been assigned for antiglaucoma preparations only.


This group comprises drugs used in ophthalmological surgery.
Miotics are classified in S01E - Antiglaucoma preparations and miotics.
Mydriatics and cycloplegics are classified in S01F.

S01KA Viscoelastic substances

Hyaluronic acid injection used during surgical procedures on the eye (e.g. 4-20 mg/ampoule) is classified in this group. Hyaluronic acid injection for intra-articular administration (e.g. 2.5 mg/ampoule) used in the treatment of arthritis is classified in M09A - Other drugs for disorders of the musculo-skeletal system.
Hypromellose is classified in this group. Hypromellose used as artificial tears is, however, classified in S01XA20.

S01KX Other surgical aids

Preparations containing e.g. enzymes (chymotrypsin) for use in eye surgery, are classified in this group.
Mitomycin used in glaucoma surgery is classified in L01DC03.

Last updated: 2021-12-14