How to determine the age and tenderness of ointment? How to deal with being too old or too young??

How to determine the age and tenderness of ointment? How to deal with being too old or too young?‌

I. Criteria for Assessing the Consistency of Medicinal Plasters‌

‌Visual and Tactile Evaluation‌

‌Qualified Standard‌: The plaster should exhibit a "black as lacquer, bright as mirror" appearance, adhere immediately upon application, and separate easily when peeled off.

‌Too Soft‌: The plaster feels sticky and is difficult to separate, forming long, unbroken strands when stretched.

‌Too Hard‌: The plaster does not stick to the skin, breaks easily when pulled, or fails to form continuous strands.

‌Experimental Testing Method‌
Place a small amount of plaster in cold water, knead repeatedly, and observe:

Sticky with long, unbroken strands → Too soft;

Non-sticky and brittle → Too hard;

Moderately adhesive with breakable strands → Optimal consistency.

‌II. Handling Methods for Improper Consistency‌

‌Remedy for Too Hard Plaster‌
Add an appropriate amount of vegetable oil (such as sesame oil) refined via the "dripping into pearls" process, mix well, and continue heating until the adhesive property is restored.

‌Remedy for Too Soft Plaster‌

‌Before Cooling‌: Heat directly until the consistency is suitable;

‌After Cooling‌: Recommend remelting a batch of properly hardened plaster for mixing to avoid re-heating, which may increase stickiness.

‌III. Key Considerations‌

‌Oil-Litharge Ratio Control‌: Adjust according to season and region, with the recommended ratio being 1:0.38~0.45 (post-refined weight);

‌Operational Environment‌: Maintain stable temperatures during heating to prevent over-hardening due to excessive heat or duration;

‌Principle of Slightly Harder‌: Over-soft plasters are harder to remedy, so slightly harder consistency is advised during preparation.

ST104A Plaster softening point meter/tester is designed and manufactured strictly in accordance with the method for the determination of the softening point of ointments 2102 in 2020. This method is used for the determination of the temperature when the plaster is softened by heat under specified conditions, that is, the temperature when the plaster falls to 25mm due to heat according to the following method.

It can be used to detect the aging degree of the plaster and indirectly reflect the viscosity of the plaster.