I came across this article from our own Dr. B. I find it very informative and it presents another side of the picture other than just Paula always saying how bad jars are because they degrade products stability.



Stability

Leslie S. Baumann, M.D.



Article Outline
• Copyright

DR. LESLIE S. BAUMANN is director of cosmetic dermatology at the University of Miami. To respond to this column, write to Dr. Baumann at our editorial offices.

Ingredients such as alpha hydroxy acids or copper peptide are often the reason why our patients buy cosmeceutical products. However, other properties also impact the efficacy of these products. Dermatologists need to understand these properties and how they affect patients' skin.

I spoke with Dr. Donald S. Orth, director of scientific affairs at Neutrogena Corp., about the importance of making sure that products remain stable and active from the time of manufacturing until the time they are used by our patients.

As we know from clinical research, what works well in the lab may not be feasible in the real world because of packaging issues, problems with shelf life, loss of potency over time, temperature instability, ultraviolet radiation, and exposure to the environment.

Dr. Baumann: How is product stability evaluated?

Dr. Orth: Stability testing is conducted on both cosmetics and drugs under guidelines issued by the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use and the Food and Drug Administration. Samples of drugs are placed under accelerated storage conditions (40° C with 75% relative humidity) to predict tentative expiration dates.

These dates are confirmed by testing at 25° C with 60% relative humidity for at least 3 years.

Other testing includes storage at 50° C; exposure to sunlight, ultraviolet radiation, and fluorescent light; compatibility testing of the product and its packaging; and cycling products through freeze-thaw conditions.

Samples of each drug are tested at specified time periods and examined to determine that the active ingredients remain within target ranges and that product characteristics meet established specifications. Even though cosmetic products do not contain active ingredients, they are studied in a similar manner and tested at various times to demonstrate that they are stable for their intended shelf life.

Dr. Baumann: What are the most common preservatives added that can increase the shelf life of cosmeceuticals?

Dr. Orth: Although the FDA considers both antioxidant and antimicrobial agents to be “preservatives,” we should focus on antimicrobials. An antimicrobial preservative is a compound that kills microorganisms or inhibits their growth. Preservatives are included in a product only at the concentration needed to prevent spoilage due to the inadvertent addition of microorganisms. Esters of paraaminobenzoic acid, also called the parabens, are the most common preservatives used in cosmetic and drug products. Methylparaben and propylparaben are used most frequently.

Fragrances and preservatives have been identified by the North American Contact Dermatitis Group as the two classes of chemicals that are responsible for the majority of visits to dermatologists' offices by patients following product use.

Although most people are able to tolerate levels of preservatives normally used to control microbial growth in products, some may experience adverse reactions to any chemical preservatives, including the parabens.

Dr. Baumann: What should dermatologists instruct patients to do to improve the stability and shelf life of cosmeceuticals?

Dr. Orth: Product stability may be improved in several ways. Patients should be instructed to avoid excessive heat by storing products at room temperature; to avoid excessive moisture by keeping products out of moist or humid areas; to avoid exposure to sunlight since stability can be degraded by excessive heat or ultraviolet light exposure; and to avoid introducing water into products either while bathing or by moistening product applicators.

Although window sills in shower stalls often are convenient for storing shampoos or conditioners, sunlight may cause product deterioration and color changes.

Dr. Baumann: Are certain compounds difficult to formulate because of stability issues?

Dr. Orth: The art and science of formulation is not as easy as it appears. The efficacy of formulations depends on the stability and bioavailability of key ingredients. For example, vitamin C and retinol require stringent conditions involving antioxidant systems, low shear mixing, inert atmosphere, protective lighting (for retinol), and protective packaging. Years of extensive research and development were required to bring stable retinol and vitamin C formulations to the market.

Dr. Baumann: Once a product is formulated and shown to be stable, are there manufacturing issues that can still affect the stability of the product?

Dr. Orth: Although many ingredients may have excellent stability under normal use by consumers, high temperatures of 70°-80° C for 30 minutes, which may be necessary during manufacturing, may cause problems with ingredients such as retinol and vitamin C, sunless tanning compounds (dihydroxyacetone), enzymes, fragrances, and preservatives.

Dr. Baumann: How can a dermatologist evaluate whether a company is properly testing its products?

Dr. Orth: Reputable manufacturers expend a great deal of time and money in formula development and testing. Analytical and preservative efficacy testing is used to guide formulators during the development of formulas. Testing is done on lab batches, pilot plant batches, scale-up batches, and full production batches. These tests are also performed to assess the concentration of active ingredients, integrity of formulas, and efficacy of preservatives throughout stability studies.

Dermatologists should look carefully at companies offering products or product development services. The company should have an established record of making quality products.

Besides looking at studies that demonstrate product safety and performance, ask to see procedures that ensure continued compliance with current good manufacturing practices.

Ask about validation of test methods, and review stability reports to see that the data support the product's expected shelf life. I believe that it's best to spend time in the beginning making sure that a particular company is the one you want for your partner, rather than spending time later to fix problems.

PII: S0037-6337(02)70217-9

© 2002 International Medical News Group. Published by Elsevier Inc. All rights reserved.


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What I get from this is companys know all about stability and spend a lot of time and money making sure their products are stable. It seems the issue regarding jars and light entering the jar and thus rendering the ingredients unstable/worthless applys only to sunlight or ultraviolet light being able to degrade the ingredients, not any light. So I take this to mean the light from your bathroom entering the jar wouldn't hurt the product at least not to the degree Paula has brainwashed us to believe! I always wondered why she was really the only one talking about how bad jars are and why big companys like Clinique or Neutrogena would continue to use them if they instantly degraded their product. Why would they even bother to develop a state of the art product if they knew a jar would negate that? What do you all think, am I on the right track here???