Papaya Enzyme (Papain) Stability in Formulations

Based on the information available, here are the answers to your specific questions:

1. When dissolved in water, does Papaya Enzyme (Papain) efficiency decrease continuously, meaning its lifespan is less than a year from dissolution?
   Yes, for standard Papaya Enzyme (Papain), its efficiency will decrease continuously once it is dissolved in water. The product description indicates that formulations where Papain is not dissolved until use (like powder cleansers) are suitable for achieving a shelf life of over 1 year. This implies that in a liquid formulation where the enzyme is constantly dissolved, the shelf life will likely be shorter than the powder form's shelf life (which can be 12-25 months depending on storage temperature).

2. Does the enzyme still degrade at pH 5.5-7, and is the lifespan in the product less than a year? How many months can it last when mixed in a product?
   While a pH range of 5.5-7.0 is recommended for maximum stability of standard Papaya Enzyme (Papain), the enzyme's efficiency still decreases continuously once dissolved in water, even within this optimal pH range. The exact lifespan in a liquid formulation is not specified in months, but the continuous degradation suggests it would be less stable than the powder form. For better stability in liquid formulations, consider using modified versions like Linked Papain or HyaCap™ Papain, which are designed for improved stability when dissolved and have a shelf life of at least 2 years.

3. Does "efficiency decrease continuously" refer only to Papaya Enzyme (Papain) itself, not other ingredients in the product?
   Yes, the statement "efficiency decrease continuously" refers specifically to the activity of the Papaya Enzyme (Papain) itself. It means the enzyme's ability to perform its intended function (exfoliating skin cells by breaking down proteins) diminishes over time once dissolved. This degradation of the enzyme does not mean that other ingredients in your formulation will also necessarily degrade or "go bad" because of the Papain.

In summary, standard Papaya Enzyme (Papain) is most stable in powder form. Once dissolved in water, its activity will gradually decrease, even under optimal pH conditions (5.5-7.0) and temperature (below 40°C, ideally stored cool). For liquid formulations requiring longer shelf life and stability of enzyme activity, modified versions like Linked Papain or HyaCap™ Papain are more suitable options.