Test focus:

Chemical Resistance: Products containing strong acids or bases, particularly those containing strong acids or bases, may corrode the glass surface. This corrosion may cause glass flakes to break off, form visible particles, or imperceptibly damage the integrity of the glass. Furthermore, these substances can dissolve alkali metal ions. If these ions accumulate on or within the glass, they can cause a dramatic shift in the glass's pH, altering its chemical properties and ultimately affecting its performance and lifespan.

Inner layer surface treatment: whether the release agent, siliconizing agent or other inner coating is compatible with the contents, whether it migrates or affects the stability of the contents.

Metal Cap/Pump Head Compatibility: While glass itself is inert, the accompanying metal cap (available in tinplate or aluminum) and pump head (made from various types of plastic and metal springs) must be compatible with the contents. This is because corrosion and rusting can contaminate the contents and even prevent proper function.

Seal Compatibility: The cap lining (e.g., PE foam padding, PVC padding, cork) or pump head seal must be compatible with the contents.

Physical shock: Skincare Glass Bottle is fragile, but it is necessary to ensure that the characteristics of the contents (such as viscosity, presence of solid particles) do not increase the risk of breakage during normal use and transportation (although not strictly a compatibility issue, but relevant).

Main test methods:

Glass particle/delamination test: Pour the contents or a specific corrosive solution (such as dilute acid or alkali) into a glass container, store it at high temperature (such as 121°C) or accelerated conditions for a certain period of time, and assess the risk of delamination by visual inspection, light obscuration particle counting, and ICP-MS detection of the dissolved silicon, boron, sodium and other elements (refer to USP <660> or similar methods).

Inner coating stability: Observe whether the inner coating has peeling, dissolution, blistering, etc.; check whether there is any migration of coating components in the contents.

Metal parts corrosion test: Check whether the metal cover, pump head spring, etc. are rusted or discolored; detect whether the content of metal ions (such as Fe, Sn, Al, Cr, Ni) in the contents is abnormally elevated (AAS, ICP-OES/MS).

Seal Compatibility Testing: Similar to testing for seals in plastic containers (swelling, migration, weight change).

pH Monitoring: Alkali released from glass may cause an increase in pH, which requires close monitoring during stability testing.