In the competitive world of personal care, creating a successful sunscreen is a complex science. You need a product that not only feels great on the skin but also delivers the expected sun protection factor (SPF) performance from the first day to the last. With the introduction of the new ISO 23698:2024 standard, the pressure to prove photostability is higher than ever. This shift demands a move beyond traditional, time-consuming stability tests toward more advanced, rapid methods. It’s time to look at how modern analytical techniques can provide the confidence you need in your development formulation, ensuring both compliance and consumer trust.

Highlights

• The new ISO d offers a faster, more precise way to analyze formulation stability without dilution, providing data in hours instead of months
• STEP-Technology® provides a unique, quantitative analysis of separation phenomena such as creaming and sedimentation while maintaining the sample in its original state
• Adopting these advanced methods can help you accelerate R&D, improve product quality, and support efforts to meet rigorous international standards

Table of Contents

1. The Challenge with Traditional Sunscreen Stability Testing
2. Introducing ISO 23698:2024: A New Standard for SPF Confidence
3. How STEP-Technology® Advances Formulation Analysis
4. The Practical Benefits of Direct Accelerated Stability Testing
5. Final Thoughts
6. FAQ
7. References

The Challenge with Traditional Sunscreen Stability Testing

For years, formulators have relied on long-term aging studies, storing samples at various temperatures and humidity levels for months or even years. While essential for final validation, these methods create a significant bottleneck in the R&D cycle. To speed things up, formulators often turn to centrifugation or simple visual inspection, but these methods have their own drawbacks. They can be subjective, fail to detect subtle instabilities, and may not accurately reflect how a product will behave over its entire shelf life.

A sunscreen is a complex emulsion, a delicate balance of oil-soluble UV filters, water-soluble ingredients, emulsifiers, and stabilizers. Any instability, such as creaming, coalescence, or phase separation, can compromise the uniform film of UV filters on the skin, directly impacting the product’s SPF efficacy and safety. In a rapidly growing market, where the global sun care industry is projected to expand significantly, getting a stable, effective product to market quickly is a major competitive advantage. Traditional testing methods make it difficult to rapidly screen and optimize a new development formulation, leading to longer development times and increased risk. The core challenge lies in obtaining fast, reliable, and predictive stability data, a problem that modern analytical tools are now solving.

Introducing ISO 23698:2024: A New Standard for SPF Confidence

The regulatory landscape for cosmetics is constantly evolving to enhance consumer safety and product transparency. The arrival of ISO 23698:2024 marks a critical step forward for the sunscreen industry. This international standard specifies a method for assessing the photostability of a sunscreen product’s SPF. In simple terms, it provides a standardized way to determine if a product maintains its protective capabilities after being exposed to a controlled dose of UV radiation that mimics sun exposure.

Why does this matter so much? Before this standard, different markets and testing houses used varied methodologies, making it difficult to compare results and ensure consistent product performance globally. ISO 23698:2024 harmonizes this process, requiring robust, reproducible data to substantiate photostability claims. For formulators, this means the pressure is on to prove that your product’s SPF value does not degrade under real-world conditions. This new standard elevates the importance of early-stage stability analysis, as identifying and resolving potential photodegradation or formulation breakdown during development is now more crucial than ever for market access and compliance.

How STEP-Technology® Advances Formulation Analysis

To meet the demands of modern formulation and rigorous standards like ISO 23698:2024, you need analytical tools that deliver speed and precision. This is where STEP-Technology® (Space- and Time-resolved Extinction Profiles) comes in. This innovative technology, at the core of LUM GmbH’s analytical instruments, provides a direct and non-invasive look inside your formulation to quantify stability in its original state.

Here’s how it works: The instrument scans your sample with light of a specific wavelength and measures the transmission of that light across the entire sample height. Over time, as particles or droplets cream, settle, or coalesce, the light transmission profile changes. STEP-Technology® captures these changes with high resolution, creating a fingerprint of the separation process. This allows you to:

• Quantify instability: Measure the velocity of separation and clarify the different instability mechanisms at play
• Analyze directly: Test your sample in its original concentration without dilution, which can alter the very stability you are trying to measure
• Accelerate results: Obtain a comprehensive stability ranking for multiple formulations in minutes or hours, not months

By providing clear, quantitative data, this technology moves you beyond subjective observation to data-driven decision-making. For anyone working on a complex development formulation, having access to such powerful insights early in the process can support more informed formulation decisions. This is one of the reasons DKSH offers advanced analytical instruments from LUM GmbH to support formulation development and stability analysis.

The Practical Benefits of Direct Accelerated Stability Testing

Adopting Direct Accelerated Stability Testing powered by STEP-Technology® translates directly into tangible benefits for your R&D lab and your business. It is about more than just collecting data; it is about using that data to make smarter, faster, and more confident decisions throughout the entire product lifecycle.

The primary advantage is speed. In an industry where time-to-market is critical, the ability to predict long-term stability in a fraction of the time is invaluable. According to research by McKinsey & Company, leading companies are drastically cutting product development timelines, and accelerated testing is a key enabler of this agility. Instead of waiting six months to see if a formula is viable, you can get a clear indication in a single day. This allows your team to screen more ingredients, experiment with more innovative bases, and optimize formulations more efficiently.

This leads to improved product quality and robustness. By understanding exactly how and why your sunscreen formulation might become unstable, you can proactively address weaknesses. This results in a final product with a longer, more reliable shelf life, ensuring that consumers receive the full SPF protection they expect. Ultimately, using Direct Accelerated Stability Testing helps you de-risk your development process, reduce costly late-stage failures, and build greater confidence in your product’s performance before it ever reaches the market.

Final Thoughts

The personal care landscape is evolving, and the introduction of ISO 23698:2024 is a clear signal that standards for product efficacy and stability are rising. To innovate and lead in this environment, relying solely on traditional, time-consuming methods can limit the speed of formulation development. Embracing technologies like Direct Accelerated Stability Testing with STEP-Technology® is essential for any formulator looking to create high-performance, stable, and compliant sunscreen products. It empowers you to move faster, develop better formulations, and build consumer trust with products that truly deliver on their promises. This is how you turn stability challenges into a competitive advantage.

If you are ready to enhance your formulation process and meet new industry standards with confidence, we invite you to explore our range of LUM solutions or contact our team to discuss your specific analytical needs.

FAQ

What is Direct Accelerated Stability Testing?
Direct Accelerated Stability Testing is a method used to rapidly predict the shelf life and stability of formulations, such as creams and lotions, without diluting or altering the sample. It measures changes such as creaming or sedimentation in hours or days, compared to the months or years required for traditional real-time studies.

Why is ISO 23698:2024 important for sunscreen manufacturers?
ISO 23698:2024 provides a globally recognized, standardized method for testing the photostability of a sunscreen’s SPF. It ensures that products are evaluated consistently, giving manufacturers a clear benchmark for compliance and helping to build consumer confidence that a product maintains its protection level after sun exposure.

How does STEP-Technology® work?
STEP-Technology® works by passing light through a sample and measuring the transmission profile over time and across the entire sample height. This allows it to detect and quantify particle or droplet movement, such as sedimentation or creaming, providing a direct and highly detailed analysis of a formulation’s stability.

What are the main advantages of using STEP-Technology® for sunscreen development?
The main advantages include speed, accuracy, and predictive power. It allows formulators to quickly screen and compare multiple sunscreen formulations, identify potential instabilities early, and make data-driven decisions to optimize the final product for long-term shelf life and efficacy.

Can these methods completely replace long-term stability studies?
Direct Accelerated Stability Testing is a powerful predictive tool that complements, rather than completely replaces, long-term and real-time stability studies. It is ideal for early-stage R&D, quality control, and formulation screening, allowing you to select the most promising candidates for final, long-term validation, thereby saving significant time and resources.

References

• Grand View Research: https://www.grandviewresearch.com/industry-analysis/sun-care-products-market
• McKinsey & Company: https://www.mckinsey.com/capabilities/operations/our-insights/the-need-for-speed-in-the-post-covid-19-era-and-how-to-achieve-it