Registrations Now Open for Skin Measurements & Claims Course 2023

The skin is the largest and fastest-growing organ in our bodies. Its water barrier properties are vital for our very survival, and its overall condition and appearance are essential to our health and wellbeing. It isn’t a surprise then that the skin care is the largest category in the cosmetics and personal care industry. The Principles of Skin Measurements & Claims course at TRI is designed for anyone involved in the development of new skin care products. The intensive three-day programme is designed for anyone who needs to build their knowledge rapidly in skin biology and microbiome, the measurement techniques used in the development of new skin products, and best practice in claim substantiation and experimental design. It will take place online on the 18th, 19th and 20th October 2023, live and on playback.

Registrations are Now Open ➡️ REGISTER HERE

ATR-FTIR imaging of corneocytes on tape-strips (taken from ‘Microscopy of the Skin’, Day 3 of the course)

Course Content

Day 1 (18th October) will introduce attendees to skin biology and the skin microbiome, and will feature our first guest speaker, Dr Kimberley Capone (Independent Consultant, US), a renowned expert on skin microbiome research. Dr Capone will take attendees through all the latest techniques available for characterising the skin microbiome and advise on how best to interpret the results.

The second part of Day 1 will introduce attendees to the laws and regulations that apply to cosmetics claim support, and how to start build a claims testing programme for new skin care products. The day will finish with a fun Kahoot! quiz to test attendees’ recall of the key points made in the day.

In vitro models, such as cell cultures, living skin equivalents and cultured follicles, are vital for the development of new skin products and claim substantiation. Day 2 (19th October) will focus entirely on the latest developments in the field of in vitro skin testing and will feature three guest speakers from leading, global skin research laboratories. Dr Elodie Gras-Lavigne (Neuron Experts, France) will update attendees on the latest developments in skin cell cultures incorporating neural cells for different skin applications. Dr Marta Bertolini (Monasterium Laboratories/QIMA Life Sciences, Germany) will then share the latest news in the development of cell and organ cultures for hair growth research. Finally, Dr Silvia Letasiova (MatTek Europe, Slovakia) will speak about the use of reconstructed human skin models for safety and efficacy testing. Day 2 will finish-off with a lecture from the TRI team on the design of in vitro skin penetration testing methods, and, of course, a Kahoot! quiz.

Day 3 will focus on the skin testing methods available from the skin and bio-substrates team at TRI Princeton. Lectures will cover spectroscopy testing, UV protection testing, skin moisture testing and microscopy of skin sections and skin cells.

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Preview the Detailed Programme Below

Course Agenda

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The Course and Continued Professional Development

The Principles of Skin Measurements & Claims course is designed to support personal training plans and continued professional development. All attendees will receive a certificate of attendance at the end of the course. Furthermore, there will also be an on-line self-assessment exam for attendees wanting to achieve a formal ‘pass’ certificate. All the course videos will be available to stream on-line for three months after the course, and slides for the presentations will also, where possible, be made available for further study.

Registration

Registration for the course costs $250 per person, and there is a 10% Early-Bird discount for registrations before Friday 15th September. There are some free places for attendees who are employees of TRI Member Companies. When these free places are taken there are still discounts for Member Companies. For more details visit the registration website.

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For more information about TRI and our events click here https://www.triprinceton.org

Beyond the Tube: Unlocking the Fascinating Science Behind Your Lipstick's Performance

Dr. Xuzi Kang, TRI Princeton

Postdoctoral Fellow

So, you've got your favorite lipstick, but have you ever wondered what makes it glide on your lips as smooth as a buttered penguin sliding down an icy slope? In the realm of cosmetics, lipstick stands as an iconic symbol of elegance and beauty. However, behind the simplicity of its application lies a complex world of scientific analysis. Today, we venture into the science of lipstick testing, unearthing how texture analyzers assess the smoothness and hardness of lipsticks and how the field of Differential Scanning Calorimetry (DSC) decrypts the mysteries of their melting behaviors.

The intricacies of lipstick texture

At TRI Princeton, Dr. Xuzi Kang has developed methods to measure the texture of lipsticks with a texture analyzer setup that is close to real life. The methods exploit a domain known as tribology, the science of interacting surfaces in relative motion, or in simpler terms, the study of friction, wear, and lubrication. Here, the texture analyzer's task is to emulate the contact between the lipstick and the lips.

In the tribology study, 1). the lipstick is applied onto a special substrate that mimics human lips’ texture and characteristics. A lipstick held by a tubal probe glides across the surface, recording the friction force. Lower friction suggests a smoother application, providing a pleasant, effortless user experience. 2). A needle probe penetrates the lipstick, recording the hardness force and adhesiveness force. Higher forces show the lipstick is harder and more adhesive, and lower forces show the lipstick is softer and less adhesive. A lipstick too firm might result in a difficult application process, and too much adhesiveness might result in a heavy or sticky application experience. 3). A transfer test is also performed to provide essential insights into its performance and wearability.

Figure 1. Lipstick friction setup and sample graph. The friction fixture is designed to drag the lipstick left and right along the special substrate. A tube holder is used to secure the lipstick. To mimic real-life usage, the lipstick is set at an angle of 60 degrees, and 80.0 g weight is added. Each stroke is 60.0 mm in length and three cycles were performed. The resulting graph is generated simultaneously.

Table 1. The table shows the net payout, initial stiction, friction, and friction reduction when layering different types of products. We can see from the data that most types of lipsticks offer decent payouts except the two special ingredient ones. Creamy 1 has the least initial stiction, which indicates that it is the easiest to begin sliding on the lips. Matte lipsticks show more friction than other types, which indicates a less smooth application. For most lipsticks, friction decreases when laying, but special-ingredient #2 shows increasing friction when laying, which is rare and not a desirable quality when using a substrate that mimics human lips.

Figure 2. Lipstick needle penetration setup and sample graph. A 1.0 mm diameter needle was used to puncture each lipstick three times, and the resulting graph is generated simultaneously.

Figure 3. Hardness and adhesiveness are shown for different types of lipsticks. The special-ingredient #2 lipstick is the firmest and the most adhesive, followed by the matte 1 lipstick; while shimmery 2 is the softest and least adhesive.

Figure 4. Lipstick color transfer setup and transfer results. Clean substrates were put on the application samples with the smooth side facing each other with a 300 g weight on top for 10 seconds to mimic kissing. Weight transfer is measured. Matte lipsticks transfer very minimally, while creamy and shimmery lipsticks transfer the most.

The melting mystery: unraveled by DSC

DSC stands as the key that unlocks the secret of lipstick’s thermal behavior. This thermoanalytical technique measures how a material's heat capacity alters with temperature, thereby shedding light on lipstick's melting characteristics.

During a DSC test, the lipstick sample is heated at a controlled rate in a furnace. As the lipstick starts melting, it absorbs heat, resulting in a difference in heat flow relative to a reference. This difference, charted against the temperature, manifests as a DSC curve.

The onset of this curve's peak signifies the beginning of the melting process. The peak's highest point denotes the lipstick's melting point, an essential indicator of the product's stability and its behavior under varying conditions. The energy required for the melting process, known as the enthalpy of fusion, is calculated from the area under the curve.

Intriguingly, DSC also unveils the degree of crystallinity in the lipsticks, which shows the uniformity of the polydisperse molecules within the composition. A lipstick with a high crystalline structure will present a sharp DSC peak and a higher melting point, signaling a robust structure. In contrast, lipstick with less crystallinity structure will showcase a broader peak and a lower melting point, indicating a softer, more malleable composition.

Figure 5. The sample DSC melting curves of lipstick show different thermal behaviors of the lipstick when it is melted, cooled down, and melted again.

Table 2. The melting behaviors of the lipsticks are shown. After melting, cooling, and re-melting, the enthalpy decreases which means less energy is required for the re-melting process. So, if your lipstick is accidentally left in the car and it melted, when you bring it back to life, there is an inevitable alteration in the lipstick's original properties.

Figure 6. There is a correlation between hardness and melting point despite different brands of lipsticks being used. Shimmery 2 has the lowest melting point, which indicates it has a softer composition. The special-ingredient #2 has the highest melting point which indicates it is firmer.

In conclusion

Lipsticks are not only skin deep, they are a combination of art and science — a product of creative color theory and meticulous chemical engineering. Behind each glamorous shade is a series of tests and measurements ensuring that it's pretty and also performs well. By utilizing the methods above, it is easy to assess different characteristics of your lipsticks, such as smoothness, hardness, wearability, and melting.

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Looking to launch a new lipstick line or enhance your current line? For more information about these and other relevant lipstick testing methods, contact us at TRI.