Why pH Matters: A Look Into HOCl Formulations
Hypochlorous acid (HOCl) based antiseptic products are gaining rapid popularity in the medical world for their ability to effectively disrupt biofilms and their strong anti-microbial properties. From wound irrigation to diabetic foot ulcer treatment, HOCl presents a strong solution with minimal skin irritation and additional anti-inflammatory properties. However, not all hypochlorous acid solutions are created equally. In this blog post we take a look at pH balance, why it’s integral to HOCl solutions, and how to determine whether the product you’re using is stable and effective.
Not All HOCl is Created Equally
Hypochlorous acid (HOCl) has been gaining popularity as a topical antiseptic product for its antibacterial and anti-inflammatory properties. However, not all hypochlorous acid products are the same—deviations in formulation and the way the product is created have serious implications in the product’s ability to rid the skin or wound of harmful microbes, pathogens or biofilms.
While HOCl may be an effective antimicrobial with incredible biofilm disruption properties, without an optimized formulation and careful attention to pH balance, the product may lack efficacy and stability¹. Therefore, it's important to understand the role of pH in the efficacy of HOCl as an active ingredient. Here, we look at why pH matters and what you should be looking for in a professional hypochlorous acid formulation.
Why pH Matters
The pH scale ranges from 0 to 14, with 7 being neutral. A pH below 7 is considered acidic, while a pH above 7 is considered alkaline. HOCL has efficacy at a pH range from 3.5 to 5.5, making it an acidic solution. When HOCL is used as a topical skin product, it is essential to maintain its pH within its natural range. If the pH level deviates too far from this range, it can compromise its effectiveness as an antibacterial and anti-inflammatory agent¹.
Figure 1. Types of chlorine compounds in water. Graphic representation of the span of chlorine compounds in water across the pH spectrum. Green signifies the HOCl zone, with the optimum for practical purposes lying between 3.8 and 5.5. On either side of that range, other Cl species come into play and detract quickly from the performance of HOCl. (Source: The Handbook of HOCl, 2020)
Higher pH-balances indicate that the chlorine species present in a formulation is mainly sodium hypochlorite (bleach), lower pH-balances indicate a higher percentile of active hypochlorous acid. HOCl is >95% of the chlorine type present between pH 3.5-5.5. At pH 7.4 only 56% of the chlorine species in solution is HOCl; the remainder is OCl-. Once the PH increases above 5 it begins to convert (dissociate) into bleach which can be damaging and toxic to skin and lung cells.
While pH balance is integral to the formulation’s ability to effectively sanitize the skin with minimal irritation, the pH balance of a particular formulation also indicates its stability and overall shelf life. The stability of HOCl is best at pH levels between 3.5 and 5.5¹. Stabilized and pH-neutral HOCl is a superior antimicrobial agent in comparison to non-stabilized HOCl formulations¹. It is also important to note that in a more alkaline environment, a majority of the active HOCl can convert to OCl¹.
Benefits for the Skin
When creating a hypochlorous formulation, it is vital to consider the pH balance of the skin, in order to create a pH range that is optimal for the skin, leading to less irritation and skin reactivity¹.
Skin pH is naturally acidic, around 5.5, which helps to maintain its natural barrier function. If the pH of HOCL skin products is too alkaline, it can disrupt the skin's natural pH balance and lead to irritation, dryness, and other skin problems¹. Formulations that are made within the natural range of the skin’s pH balance can allow for all of the active microbial benefits of hypochlorous acid, while minimizing adverse reactions such as itching, dryness, and irritation. In fact, when it comes to more sensitive applications such as wound care, a lower (slightly more acidic) pH has been shown to improve healing rates².
Considering all of the following factors, pH balance is crucial when it comes to the effectiveness and safety of HOCL as a topical product. It is important to use products that have a pH within its natural range to ensure that it works optimally and doesn't cause any harm to the skin. Likewise, it’s important to consider the pH balance of a hypochlorous acid product when considering the stability of the active ingredient.
BIHOCL Knows Balance
When it comes to formulation, we want to ensure that we are providing health care experts with a hypochlorous acid product that is within an optimal pH balance. BIHOCL hypochlorous technology is created through a sophisticated engineering process, however at its core our formulation is quite simple—medical grade salt, highly purified water, and a source of electricity.
The pH-balance of BIHOCL products are routinely and rigorously tested at our manufacturing facility and controlled by state-of-the-art technology to ensure our ideal pH-balance range is ensured with every single batch.
In addition to ensuring a pH balance, we continue to produce a solution that is physiological first. What does this mean? Well, the active percentage of sodium chloride (NaCl) present in our formulation is approximately 0.9%, meaning the solution is created in a way that mimics the body’s natural fluids as closely as possible.
Elevate Your Practice
We know that health care professionals looking to switch to hypochlorous acid based products demand a high level of efficacy, quality, and stability in order to make the switch. And the same goes for those already using the product, as they expect the same of the product. That’s why we produce a range of products for a number of different specialties, including wound care, podiatry, eye care, and surgical irrigation.
For more, learn about our HOCl technology or explore our solutions in Eye Care and Wound Care. Contact us for more information!
- Del Rosso, J. Q., & Bhatia, N. (2018). Status report on topical hypochlorous acid: clinical relevance of specific formulations, potential modes of action, and study outcomes. The Journal of Clinical and Aesthetic Dermatology, 11(11), 36.
- Sim, P., Strudwick, X. L., Song, Y., Cowin, A. J., & Garg, S. (2022). Influence of acidic pH on wound healing in vivo: a novel perspective for wound treatment. International Journal of Molecular Sciences, 23(21), 13655.