On this page: Water used in the manufacture of sunscreen products | Process validation for sunscreen manufacturers | Supplier qualification for sunscreens | Labelling and packaging
Water used in the manufacture of sunscreen products
Water used in the cleaning and formulation of sunscreens should be of an appropriate quality such that the finished product meets all chemical and microbiological quality attributes at release and throughout its shelf-life.
Using purified water
Purified Water is preferable for use in the manufacture of sunscreens, as per the default standards i.e. the British Pharmacopoeia (BP), European Pharmacopoeia (EP) or United States Pharmacopeia – National Formulary (USP).
If the ingredient list on the ARTG for a sunscreen product includes ‘purified water' as a persistent ingredient then the water used in the sunscreen product must meet the requirements of Purified Water EP, BP or USP.
Using potable water
Where authorised by the specific marketing authorisation, it may be acceptable to use potable water in the manufacture of sunscreens. Potable water can be reasonably pure; however, it is always variable and, in some regions, of very poor quality.
When using potable water it may be necessary to substantially remove impurities and to control microbial levels to prevent product contamination. For an aqueous-based formulation water should be considered as a critical input.
Specification for process water
Where potable water is used in the manufacturer of sunscreen products, a specification for ‘process water' should be developed based on sound physical, chemical and microbiological principles taking into consideration relevant items such as:
- risk of chemicals commonly added to city water supplies and what effect these additives may have on product quality or stability.
- possible effect seasonal variations may have on source water quality.
- effect of manufacturing process on water quality, such as where water is heated to assist in emulsification, and how these processes will be controlled, recorded and validated.
- 'target', 'warning' and 'action' levels for microbiological load should be set based on risk and with consideration to the specification for in-process and final product, for example compliance with TGO 77, or the TGO that replaces this Order. The 'action' limit should not generally exceed 102 cfu/mL at point of use but may be set at a figure orders of magnitude lower.
Microbial testing affected by municipal supplier water treatments
Where potable water is to be used for product formulation additional consideration must be given to the water treatment processes used by the municipal supplier that might affect microbiological testing.
The addition and presence of chlorine for example, in potable water may prevent detection of viable microorganisms rendering test results unreliable. In these cases, the addition to the sampling vessel of a suitable and sufficient neutralising agent, for example sodium thiosulphate, may be required.
Additional monitoring of water quality when using potable water
Additional monitoring may be required to assess the quality of water following extensive sanitation of the water system by the municipal supplier. For example, it is common for additional sanitation of the water supply system to occur after a breach of the potable water catchment area or purification system, which may result in sloughing biofilm from the potable water distribution system that might not be detected by the sunscreen manufacturer prior to use of the water for product manufacturer.
Additional verification of microbiological testing method when using potable water
The sample size selected for microbiological testing of process water should be enough to give a countable number of colonies using the test method employed. A recommended test method is the relevant British Pharmacopeia/European Pharmacopoeia monograph for microbiological monitoring of purified water; however, further verification of the method may be required when analysing potable water.
Higher frequency of sampling when using potable water
High frequency sampling of potable water systems would be expected due to their inherent variability and lack of user control. Samples should be tested for microbial load and indicator organisms.
Water testing frequency
All water used in the manufacture of sunscreen products should be tested sufficiently frequently to demonstrate that it meets the requirements for Purified Water (BP/EP/USP), or the manufacturer's specification for process water, whichever is appropriate.
The frequency of water testing should be based on risk considering the data collected from qualification and historical monitoring of the water system, potential levels of contaminants (including microbial) and risk to product quality.
Process validation for sunscreen manufacturers
A separate guidance document is available for Process validation for listed and complementary medicines, which can also be applied to sunscreens.
Supplier qualification for sunscreens
A separate guidance document is available for Supplier assessment, approval and qualification for listed and complementary medicines, which applies to sunscreens.
Labelling and packaging
Label counting and verification
Roll labels must be counted either on receipt or at issue. Supplier counts are not acceptable unless the supplier is specifically qualified and the supplier certifies the exact count for each roll. Supplier sequential numbering on the backing web of labels is an acceptable alternative.
You, the manufacturer, must count and effectively verify cut labels, because of the risk of mix-ups.
Unique batch numbering
The system that you adopt for batch numbering may include numerals, letters or symbols (or any combination of these) and must effectively serve to identify uniquely a batch of product, and from which it is possible to trace that batch through all stages of manufacture and distribution. You should be able to demonstrate that the system for batch numbering meets these requirements and is effective.
Unpacked bulk products, should have a batch number that is unique to both product and batch, to minimise the potential for mix-ups during manufacturing. For finished products that are easily distinguished, a batch numbering system that only designates batches from that product may be acceptable.
The topic of batch numbering is dealt with in Medicines labels: Guidance on TGO 91 and 92.