PD ISO-TR 18811-2018

BSI Standards Publication WB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06 Cosmetics — Guidelines on the stability testing of cosmetic products PD ISO/TR 18811:2018National foreword This Published Document is the UK implementation of ISO/TR 18811:2018. The UK participation in its preparation was entrusted to Technical Committee CW/217, Cosmetics. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. © The British Standards Institution 2018 Published by BSI Standards Limited 2018 ISBN 978 0 580 83027 3 ICS 71.100.70 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was published under the authority of the Standards Policy and Strategy Committee on 28 February 2018. Amendments/corrigenda issued since publication Date Text affected PUBLISHED DOCUMENT PD ISO/TR 18811:2018© ISO 2018 Cosmetics — Guidelines on the stability testing of cosmetic products Cosmétiques — Lignes directrices relatives aux essais de stabilité des produits cosmétiques TECHNICAL REPORT ISO/TR 18811 Reference number ISO/TR 18811:2018(E) First edition 2018-02-15 PD ISO/TR 18811:2018 ISO/TR 18811:2018(E)ii © ISO 2018 – All rights reserved COPYRIGHT PROTECTED DOCUMENT © ISO 2018, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 • CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyright@iso.org www.iso.org PD ISO/TR 18811:2018 ISO/TR 18811:2018Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 4 Basic principles of cosmetic stability 2 5 Aspects to be addressed during stability testing 3 5.1 General . 3 5.2 Stage/scale of tested batches . 3 5.3 Test procedures and conditions . 4 5.3.1 Principle 4 5.3.2 Temperature and humidity . 4 5.3.3 Cycling of temperature and/or humidity . 5 5.3.4 Vibration . 6 5.3.5 Centrifugation 6 5.3.6 Exposure to light (photostability) . 6 5.4 Physical, physico-chemical and chemical alterations 7 5.4.1 Physical destabilization phenomena of different product types 7 5.4.2 Chemical destabilization processes . 8 5.4.3 Destabilization phenomena . 9 5.4.4 Specific test methods 10 5.5 Microbiological aspects 12 5.5.1 General.12 5.5.2 Microbiological parameters 12 5.5.3 Testing conditions 12 5.5.4 Microbiological specifications .13 5.5.5 Interpretation of results .13 5.6 Interaction with packaging 13 5.6.1 General information .13 5.6.2 Types of packing materials and main possible evaluations 13 5.6.3 Pressure vessels (aerosols) .14 6 Stability test conclusions 14 6.1 Evaluation .14 6.2 Report 14 Bibliography .15 © ISO 2018 – All rights reserved iii Contents Page PD ISO/TR 18811:2018 ISO/TR 18811:2018 Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html. This document was prepared by Technical Committee ISO/TC 217, Cosmetics.iv © ISO 2018 – All rights reserved PD ISO/TR 18811:2018 ISO/TR 18811:2018 Introduction Stability studies are aimed at assessing the ability of a product to maintain the desired physical, chemical and microbiological properties, as well as functionality and sensorial properties when stored and used under appropriate conditions by the consumer. More simply, the objective of a stability study is to determine the shelf life of a product and to evaluate whether a product in the package is stable when subjected to the market conditions in which it is sold and used. The “market conditions” encompass distribution (transportation), warehouse storage and conditions during use. Thus, the stability study may be seen as a prerequisite for ensuring product quality. Stability tests on cosmetic products are required for — obtaining a guidance on the formulation of the product, and the appropriate packaging material, — optimizing the formulation and manufacturing process, — determining conditions of transportation, storage, display and manner of use, — estimating and confirming shelf life, and — ensuring customer safety. This document identifies readily available references to assess the stability of cosmetic products on the market. Its purpose is to provide a resource for the selection of the appropriate stability tests. Although these guidelines provide a helpful starting point to evaluate new products and technologies, adapting the testing to reflect differences between product types and formulations may still be necessary.© ISO 2018 – All rights reserved v PD ISO/TR 18811:2018This page deliberately left blank Cosmetics — Guidelines on the stability testing of cosmetic products 1 Scope This document gives guidelines for the stability testing of cosmetic products. It reviews readily available bibliographic references that provide a resource for the assessment of the stability of cosmetic products. This review of the available guidelines that assess the stability of cosmetic products can serve as a technical/scientific framework to identify the most suitable methods for the assessment of the stability of cosmetic products. This document does not aim to specify the conditions, parameters or criteria of stability testing. Considering the wide variety of cosmetic products, storage and use conditions, it is not possible to define a single way to assess product stability. Therefore, it is up to the manufacturer to specify and justify the stability protocol to cover test methods, specifications and conditions at which products will be tested. 2 Normative references There are no normative references in this document. 3 T erms a nd definiti ons For the purposes of this document, the following terms and definitions apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: — IEC Electropedia: available at http:/ /www.electropedia.org/ — ISO Online browsing platform: available at https:/ /www.iso.org/obp 3.1 accelerated stability evaluation study designed to speed up naturally occurring destabilization processes due to intrinsic or extrinsic factors and which predicts the behaviour over the long term Note 1 to entry: Typically, physico-chemical, mechanical or thermal procedures are employed. 3.2 real time stability evaluation study that monitors the state of a product to determine the time course of any alteration to it under reasonably expected conditions of storage and use Note 1 to entry: Often called “long term test” or “standard stability test”. 3.3 stability ability of a cosmetic product to resist change or variation of its initial properties over time under stated or reasonably foreseeable conditions of storage and use Note 1 to entry: See Reference [1]. TECHNICAL REPORT ISO/TR 18811:2018 © ISO 2018 – All rights reserved 1 PD ISO/TR 18811:2018 ISO/TR 18811:2018 3.4 stability criteria deviations from initial properties or behaviour at production state, which are acceptable Note 1 to entry: See Reference [1]. 3.5 stability metrics properties/parameters of the state or behaviour of a cosmetic product which should be monitored according to demanded, specific product qualities Note 1 to entry: See Reference [1]. 3.6 shelf life recommended time period that a cosmetic product can be kept after its production, during which the defined quality of the product remains acceptable under expected conditions of distribution, storage, display and usage Note 1 to entry: See Reference [1]. 4 Basic principles of cosmetic stability Design, formulation and the manufacturing process of cosmetic products have to fulfil general and specific demands and requirements of distribution pathways, and especially of customers. Specification, functionality and aesthetics have to be preserved, i.e. have to be stable, over the entire life cycle of a product. Processed cosmetic products are complex matrixes which undergo spontaneous alterations to reach the free energy minimum in accordance with the second thermodynamic law. [2]These so-called intrinsic causes may be of physical, physico-chemical or chemical origin. [3]Many reactions and processes may lead, under the condition of the “market”, to a deviation from the initial, original product properties at the date of manufacturing. Departure may be caused by thermodynamically driven internal or externally driven effects, [1]microbiological impact [4][5]or interactions with packaging [6]and may finally lead to a loss of specified product functionality or/and aesthetic attributes. This impacts usability, shelf life and marketability. Destabilization processes of the original product may also be provoked, enhanced or magnified due to extrinsic (external) factors. For example, state changes may be triggered by thermal energy loss or gain, light and UV irradiation, mechanical energy input (such as vibration or pressure), oxygen uptake, humidity, interaction by or with container/closure system (packaging), and proliferation of microorganisms. [3] Cosmetics are of different natures and some consist of several phases, dispersed ones and a continuous one, and may be classified as suspensions or emulsions. Suspensions are solid particles dispersed in a liquid phase. Emulsions are composed of two liquid phases, typically oil-in-water (o/w) or water-in-oil (w/o). Cosmetic dispersions are usually very complex and may contain several phases. A stability test aims at providing information on the state/behaviour of the cosmetic products in the container/enclosure under the different conditions to which they may be subjected from their manufacturing date until the end of their recommended period of use. [7][8][9]The state of a cosmetic product and its stability depend upon numerous interrelated physical, physico-chemical and chemical parameters as well as interaction with environment, and its nature is therefore very complex. In general, they may be roughly classified as mechanical-driven, thermal- or diffusion-driven, interaction- force- driven or externally provoked processes. [1][7][10][11]There is no universal method or technique to quantify all stability aspects due to the complexity of different pathways of destabilization. Therefore, it is always necessary to specify precise stability metrics and acceptance criteria. After determination of the stability metric(s), it is necessary to select appropriate stability test methods to monitor the alteration of the product over time. It is recommended to select methods that do not require sample preparation (e.g. dilution) and quantify kinetics of the product destabilization based on defined metric(s) in a direct way. [1]Real time measurements can be made by traditional visual 2 © ISO 2018 – All rights reserved PD ISO/TR 18811:2018 ISO/TR 18811:2018 observations, sensory techniques or use of different measuring techniques which are advantageous in being quantitative, objective, traceable, reproducible and retrievable. [1]Scanning and spatially resolving techniques are appropriate in particular to detect phase separation and help to discriminate between phase separation and phase changes. [1][7][10][11] In the case of very stable products, analytical techniques having high resolution/sensitivity should be used and procedures can be required in order to accelerate the alteration to shorten the detection time to meet the predefined stability criteria. [1][11]Typical acceleration approaches are mechanical ones (e.g. high gravity by centrifugation) or elevated storage temperatures for a given time. Preservation efficacy testing (challenge-test) aims to test microbiological attributes under accelerated conditions. [3] [5]However, because of the interrelated physical, physico-chemical and chemical properties of cosmetic emulsions or suspensions, adequate acceleration methods may be chosen and verified in the context of a specific product. [1][11] Beside direct methods, correlative test methods are utilized focusing on determination of a single parameter of the state of a product that is known to correlate with product stability. [1]Typical parameters measured and compared with pre-defined acceptable values are, for example, mean particle/droplet size or zeta-potential. These quantities reflect the state at the time of the measurement and do not yield kinetic information. Such test procedures may be used for quality assessment of a specified product but, due to the complexity of the state of cosmetic products, currently no theoretical basis exists to predict the time course of any product alteration based on a single parameter obtained at any single time point. In addition, most of these measuring techniques demand sample preparation and often product dilution. [1] Due to the cosmetic product formulation’s complexity overall, caution should