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Approved names for chemical ingredients

TGA approved terminology for therapeutic goods

11 November 2019

This guidance provides information on approved names for chemical ingredients - Australian Approved Names (AANs).

Searching the list of AANs

The Ingredients Table on our TGA Business Services website contains all approved names for ingredients used in therapeutic goods.

For more information on how to search for ingredients, refer to Appendix 3.1.1.

Please note

The inclusion of an AAN in the Ingredients Table:

  • indicates that the name is approved as the descriptor of the substance.
  • does not imply that the substance has been approved for use in a therapeutic good.

If a chemical ingredient is not on the Approved List

If there is no AAN for a chemical ingredient in your therapeutic good's formulation:

Abbreviations for AANs

Chemical ingredients with long names may be abbreviated in the literature, for example:

  • cyclohexanedimethanol is referred to as CHDM
  • diethanolamine is referred to as DEA
  • dimethyl sulfoxide is referred to as DMSO
  • hydroxyethyl ethylenediamine triacetic acid is referred to as HEDTA

Please note

In your application for a therapeutic good or on medicine labels:

  • do not use these abbreviations in place of the Australian approved name
  • use the full Australian approved name (AAN).

General guidelines for naming chemical ingredients

INN is the preferred reference for AANs (see section 3.3 Ingredient naming references). If there is no INN (or other preferred reference) available for your chemical substance you can propose a new name. Use the following rules when proposing a new name:

  • use International Union of Pure and Applied Chemistry (IUPAC) naming conventions, e.g. 1-[3,3-dimethylcyclohexyl]-4-penten-1-one
  • unless the name includes a salt, ester or glycol suffix, form names by joining elements of the name together to form a single word, e.g. ethylcellulose rather than ethyl cellulose
  • capital letters are not generally used in chemical names except in the circumstances detailed below:
    • include the designator 'N-' in the name to indicate a constituent group attached to a nitrogen
    • where relevant, include stereochemical descriptors, such as 'R-' and 'S-'; 'd-', 'l-' and 'dl-'; and/or 'cis-' and 'trans-', in ingredient names, in accordance with IUPAC nomenclature. This increases the amount of information provided by the name and reduces ambiguity
  • use the designators 2-, 3-, 4-, for chemicals that include aromatic rings rather than o-, m-, p-, or ortho-, meta-, para-
  • use the designators n-, iso-, sec- and tert- to describe the branching of alkyl groups.
  • use Table 4 to identify the acceptable approach for these chemical groups.
Table 4: Names for miscellaneous chemical groups
Acceptable name Unacceptable name/spelling/format
allyl propenyl, vinyl carbinyl
amyl pentyl
anisate methoxybenzoate
anthranilate aminobenzoate
cetyl hexadecyl
glycerol glycerin
nonanoate pelargonate
nonanoyl pelargonyl
nonanoic pelargonic
phenylpropionate hydrocinnamate
phenylpropionic hydrocinnamic
phenylpropionyl hydrocinnamyl
xylene xylol

Naming of specific types of chemical ingredients

Polymeric substances

Polymeric substances are frequently identified by a name part and a number that indicates the grade of polymer by:

  • chain length or molecular weight
  • viscosity.

Some common examples are in Table 5.

Table 5: Polymeric substances identified by a name part and a number
Type of polymer Numbering system
Macrogols Average molecular weight
Dimeticones Kinematic viscosity
Carbomers, nylons, polyacrylates Numbers indicate different chemical structures rather than different average polymer chain lengths; the numbering is not systematic, and the relevant references should be consulted to determine the structure

Macrogols (polyethylene glycols - PEGs)

The term macrogol is generally used by the pharmaceutical industry, whereas PEG is used in the chemical and cosmetics industries. 'Macrogol' will be used in AANs for polyethylene glycols (and their simple esters and ethers), rather than polyoxyl, polyoxyethylene, polyethylene glycol or PEG. This is consistent with INN terminology.

'Macrogol' is the INN for polymeric substances with the following general formula:

HOCH2(CH2OCH2)mCH2OH

INNs have also been assigned to simple esters and some simple ethers of macrogols. Examples are macrogol stearate and lauromacrogol.

INN definitions

The INN definitions state that each name is followed by a number indicating the average molecular weight of the:

  • macrogol
  • macrogol portion of an ester or ether.

For example, macrogol 300 has an average molecular weight of about 300 (m = 5 or 6, giving a molecular weight of 282.3 or 326.4).

Average molecular weights

To prevent the creation of numerous macrogol names with only minor differences, such as macrogol 1500 and macrogol 1540, we will use average molecular weights in the ingredient name, rounded in the following manner:

Molecular weight for macrogols with shorter chain lengths is averaged to the nearest 50, up to a weight of 800. Following 800, the molecular weight is averaged to the nearest 100 up to 1500; then to the nearest 500 up to 8000 and so on.

Size of the polymer molecule

In AANs, the size of the polymer molecule will be based on the average molecular weight of the polymer chain, not the chain length. (Chain length, based on the approximate number of oxyethylene units, is generally used for PEG-based nomenclature.)

Where names are converted to macrogol from PEG, the chain length designating number will also be appropriately amended, and the reference will be shown as 'modified' e.g. International Cosmetic Ingredient Dictionary (modified) (ICIDM). The name listed in the reference is included as a synonym.

For example, all pure macrogols (macrogol 2000, etc.) will have references as 'modified', because the reference does not usually list the number.

Complex polymers with polyethylene glycol components

Where there are no INNs for more complex polymers with polyethylene glycol components, these are named according to the best available reference.

For example, macrogol poly(vinylalcohol) grafted copolymer is named using the British Pharmacopoeia, whereas acrylates/PEG-10 maleate/styrene copolymer is named using the International Cosmetic Ingredient Dictionary.

Carbomers

When giving different names to carbomers, we follow the conventions of the USP. This approach relies on whether or not they are manufactured using benzene.

Ensure that you refer to the synonyms in the Ingredients Table, and/or the relevant USP references, to help determine the correct name for the substance.

Derivatives

Derivatives each have individual names to identify the salt or ester and distinguish the substances from the base.

For example, 'ibuprofen' and 'ibuprofen sodium' are two separate AANs.

If a derivative has an INN

Derivatives each have individual names to identify the salt or ester and distinguish the substances from the base.

For example, 'ibuprofen' and 'ibuprofen sodium' are two separate AANs.

If there is no INN (or other common reference)

Ensure you name derivatives in accordance with the conventions described in the WHO document International Non-proprietary Names Modified, which you can find on the WHO INN Publications page.

Salts

There is no need to specify the molar ratio of the salt if:

  • there is no INN or other common reference, and
  • the salt can exist in only one form.

For example, if an ingredient can only exist as a monosodium salt, use 'sodium' in the name (e.g. sodium benzoate).

Monohydrochloride would be stated as hydrochloride, whereas dihydrochloride would be stated as is.

Please note

If there is no preferred reference, and there is more than one possible stoichiometry for the salt (and the stoichiometry is not specified), the ratio is assumed to be 1:1.

Common examples are sodium, potassium, magnesium, calcium, hydrochloride and hydrobromide.

Starches

Unmodified, naturally occurring starches are classified as herbal ingredients and have Approved Herbal Substance Names, e.g. maize starch*.

*Note: 'maize' is used to identify ingredients derived from corn.

Some starches (such as soluble potato starch) have been chemically modified, and are therefore classified as AANs.

Alcohols, aldehydes, acids, esters and acyl groups

Alcohols, aldehydes, acids, esters and acyl groups should be named in accordance with references commonly used in the pharmaceutical industry, e.g. British Pharmacopoeia (BP), Merck Index.

If there is no suitable reference in the Reference Codes list on the Code Tables:

Where numbers are included in the name:

  • place them in the middle of the name rather than at the start, e.g. butan-1-ol.

Ethanol

The Ingredients Table has two entries relating to ethanol, both of which use the British Pharmacopoeia as a naming reference. However, both have other default standards that sponsors can choose to comply with:

  • 'ethanol absolute' (BPM) which is subject to either:
    • 'ethanol' (absolute alcohol) as described in the BP monograph of that title
    • 'dehydrated alcohol', as described in the USP monograph of that title
  • 'ethanol' (BPM) which is subject to either:
    • 'ethanol (96 per cent)', as described in the BP monograph of that title
    • 'alcohol', as described in the USP monograph of that title.

Anions and cations

The quantities of individual ions (or ion equivalents) may need to be stated on a medicine label, in addition to the statement of strength for ingredients. The medicine labelling Orders include these requirements for:

  • intravenous infusions (large-volume injections)
  • concentrated haemodialysis solutions.

All approved anions and cations have AANs and are available in the Ingredients Table.

Amino acids, sugars and other chiral ingredients

Many chiral substances, such as amino acids, can exist as either:

  • a single optical isomer (enantiomer) or
  • a mixture of isomers.

The reference quoted for the name defines the isomer or mixture.

Some substances of biological origin exist in nature exclusively as a single enantiomer. These include amino acids, sugars and lactic acid. For these substances the:

  • stereochemistry of the naturally occurring isomer isn't identified in the ingredient name, e.g. 'lysine' and 'glucose' are AANs, NOT 'l-lysine' or 'd-glucose'
  • designators, 'dl-' and 'd-' should be included in the names of amino acids that occur naturally in these forms, to distinguish them from the 'l' form. This is consistent with INN naming conventions and reduces ambiguity
  • designators 'R', 'RS' and 'S' are not used for chiral molecules, unless they are in the reference title or are required to distinguish between different approved names.

Metals

Use the common name for metals when naming metal salts or complexes. For example, use 'copper' and 'iron', rather than 'cuprous' or 'cupric', and 'ferrous' or 'ferric' as they are more readily understood by consumers.

  • If a single oxidation state occurs, include it in the name, e.g. copper (I), copper (II), iron (II), iron (III))
  • Where mixed oxidation states occur, use the names copper, iron, and so on; for example, iron phosphate.

Colour names

Do not include the Colour Index (CI) number for new ingredients that are colours.

Each colour and its lakes will have separate names.

For example, erythrosine and erythrosine aluminium lake are both approved names.

Radioactive pharmaceuticals

Use the INN format for radioactive ingredients, e.g. Iometin (131I); iometopane (123I)) noting that mass numbers in AANs are not in superscript format.

Stearates

The term 'stearate' in the name of a salt or ester refers to mixtures of fatty acids that have as their major component(s) either:

  • stearic (octadecanoic) acid, or
  • palmitic (hexadecanoic) and stearic acids in varying proportions.

The term 'palmitostearate' is sometimes used where the mixture of fatty acids contains approximately equal quantities of palmitic and stearic acids.

Vitamin E substances

There are no INNs for vitamin E substances - that is, alpha-tocopherol and its derivatives. The USP and BP systems for naming vitamin E substances are different.

The AANs are essentially the same as the names specified in the USP monograph 'Vitamin E', with an additional hyphen, as demonstrated in Table 6.

Table 6: AANs and BP names for vitamin E substances
AAN BP name
d-alpha-tocopherol RRR-alpha-tocopherol
d-alpha-tocopheryl acetate RRR-alpha-tocopherol acetate
d-alpha-tocopheryl acid succinate RRR-alpha tocopheryl hydrogen succinate
dl-alpha-tocopherol all-rac-alpha-tocopherol
dl-alpha-tocopheryl acetate all-rac-alpha-tocopheryl acetate
dl-alpha-tocopheryl acid succinate alpha tocopheryl hydrogen succinate

Waters of hydration

Use the following approach for identifying waters of hydration, e.g. the waters of crystallisation of a substance:

  • if a hydration state is not included in the name, the ingredient is anhydrous. This policy is used even if the 'normal' state of the ingredient is hydrated.

    Note: In a small number of cases, the term 'anhydrous' is retained in the ingredient name to avoid confusion, e.g. 'colloidal anhydrous silica' and 'hydrophobic colloidal anhydrous silica'.

  • there are separate names for each hydration state in which the substance occurs.
  • substances that occur with a mixed hydration state are called 'substance hydrate'.

This approach to ingredient naming is consistent with INN naming conventions. The objective is to provide an unambiguous name, without users needing to refer to other documents to determine which state of hydration is defined.

Exceptions to this approach

If the water is not part of the crystal structure then some substances may include the word 'dried' as part of their name, e.g. 'dried magnesium sulfate'.

Use on labels

Waters of hydration may be expressed differently on labels.

For information on how an ingredient is expressed on a medicine label, see the medicine labelling Orders and related guidance.