Optimizing a Lotion Formula with Design of Experiment

In the competitive skincare industry, perfecting product formulas is crucial for staying ahead. Companies need to constantly improve their products to meet high consumer expectations for performance, feel, and safety. In this case study, we’ll examine the approach of a Cosmetic Formulator. They used a Design of Experiment (DOE) to refine an existing lotion formula. This optimization led to better quality and market appeal. We’ll also discuss how Topline Statistics can help other companies with similar challenges.

Background

A Cosmetic Formulator was given the task of refining a lotion formula. The objectives were to improve its viscosity for easier pouring. Another goal was to achieve the right pH for a pleasant skin feel. Lastly, they aimed to reduce production costs. The lotion was good at hydrating and soothing dry skin, but the company wanted to make it even better. They aimed to find the best mix of ingredients. They also needed to find the right amounts to meet these new goals. This approach is a design of experiment for lotions.

Objectives

1. Optimize Viscosity: Adjust the formulation to get the right viscosity for smooth pouring and efficient filling.
2. Achieve Target pH: Modify the formula to reach a specific pH level for better skin feel and product stability.
3. Reduce Production Costs: Reformulate the lotion to lower production costs while keeping or improving quality.
4. Improve Texture and Stability: Enhance the lotion’s texture for a better user experience. Make sure it stays stable over time and during storage.

Approach: Design of Experiment (DOE)

Design of Experiments (DOE) is a methodical way to explore how different factors affect a product. For this project, DOE was used to test how various ingredients and their interactions influenced the lotion’s performance.

1. Identify Lotion Factors and Levels

The first step was to identify the main factors that affect the lotion’s properties:

• Water Content: Affects hydration and consistency.
• Emollients: Ingredients like Shea butter and coconut oil that influence texture and moisturizing.
• Emulsifiers: Help mix water and oil, impacting stability and texture.
• Thickeners: Affect viscosity and how well it spreads.
• pH Adjuster: Ensures the formula reaches the desired pH level.

Each factor was tested at various levels to find the optimal formulation. While specific details of all ingredients and their exact levels are proprietary, here are some examples of the ranges explored:

• Water Content: 65%, 75%, 85%
• Emollients: 5%, 10%, 15%
• Emulsifiers: 3%, 6%, 9%
• Thickeners: 0.5%, 1%, 1.5%
• pH Adjuster: 0.25%, 0.50%, 0.75%

This approach provided valuable insights into how different combinations of these factors affected the lotion’s performance.

2. Design the Experiment Using JMP Software

With help from a consulting Statistician, several design options were considered. The Chemist chose a focused approach. They tested a manageable set of factor combinations. This allowed for meaningful results while saving time and resources. A series of experimental batches was then created to assess the impact of different variables on the lotion.

3. Conducting the Experiments on the Batches of Lotion

Each batch was prepared according to the design and evaluated based on:

• Viscosity and pH: Measured in the lab by the Chemist.
• Texture and Spreadability: Evaluated by a panel of testers for feel and ease of application.
• Stability: Monitored over a 12-month period for any changes in texture, separation, or efficacy.
• Cost: Extracted material production costs from database to calculate new formula costs.

4. Analyzing the Data

The data was analyzed to see how each factor and their interactions affected the lotion. Key findings included:

• Water Content: Higher levels improved hydration but needed balancing to avoid a watery texture.
• Emollients: A moderate amount provided the best mix of moisturizing and texture, while also reducing costs.
• Emulsifiers: A lower concentration worked well for stability but affected texture slightly.
• Thickeners: A higher concentration gave the best viscosity but made pouring more difficult.

5. Optimize and Refine for the Best Lotion

Based on the analysis, we adjusted the formula to the optimal levels. We thoroughly tested the final batch with these optimized levels. The tests showed better moisturizing, improved texture, and excellent stability.

Results and Benefits from the Lotion Design of Experiment

The optimized lotion formula achieved:

• Improved Performance: Better viscosity for filling in production
• Increased Market Appeal: A new claim based on pH being balanced
• Cost Reduction: The formula cost was reduced by >10%
• Enhanced Efficiency: The DOE approach provided valuable insights efficiently, saving time and resources.

Conclusion

Design of Experiments proved to be a valuable tool for refining the lotion formula. It led to significant improvements in viscosity, skin feel, and stability. Furthermore, for companies aiming to optimize their product formulations, Topline Statistics offers expert support in applying DOE methods. I can assist businesses in systematically exploring their processes. By refining them, they achieve better product quality. This also leads to lower costs and greater market success. If you’re encountering similar challenges, allow me to help you reach your formulation goals with precision and efficiency.

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