Analysis on the determination index of plaster adhesion

Plaster is composed of medicine and plaster cloth It is a common form of transdermal delivery system that the skin is used as the delivery channel to make the medicine continuously input into the body through the skin The plaster structure is generally non-woven fabric, adhesive (commonly used pressure-sensitive adhesive), medicine and release paper Plaster cloth is the carrier of plaster, and its adhesion performance mainly depends on adhesive, which has an important influence on the use effect of plaster preparation Because it takes a certain time for the drug to penetrate into the body through the skin, the plaster cloth must have enough viscosity to ensure the adhesion performance during the plaster application and ensure the continuous close contact between the drug and the body According to the Pharmacopoeia, the adhesive force of plaster (paste) mainly includes three indexes: initial adhesive force, adhesive force and peel strength These three indexes are closely related to the quality of adhesive used in plaster The quality of adhesive can be measured by three parameters: initial adhesion, adhesion and cohesion The initial adhesion is used to characterize the contact "viscosity" between the adhesive and the surface of the object to be adhered It can be tested by the measuring principle of the inclined rolling ball: the initial adhesion of the sample is tested by the adhesion of the sample to the steel ball when the steel ball and the adhesive surface of the sample contact for a short time under a small pressure The adhesion force is used to characterize the resistance of adhesive and adherend surface to interface separation, which is related to adhesive quality, adherend, pressure, time and environmental conditions, and can be evaluated by peel strength test Test method: cut the sample to a certain size and stick it on the test plate according to the requirements; clamp the free end of the sample and the stainless steel plate in the upper and lower clamps of the equipment respectively; start the test, the two clamps move relative to each other, and the force value sensor configured on the upper clamp records the force value generated during the stripping process in real time, so that Zui can finally calculate the peel strength and other performance indexes of the sample The cohesive force is used to characterize the internal strength of the adhesive It is usually measured by the ability of paste to resist shear creep after sticking, which can be determined by the adhesion test The test method is to hang the test plate with plaster sample vertically on the test stand, and hang the weight of the specified weight at the lower end, and use the displacement of the sample after a certain time, or the time when the sample completely disengages, to characterize the resistance of the adhesive sample to pull off Initial adhesion, adhesion force and cohesion are three independent parameters of adhesive, which can not be confused and need to be controlled reasonably Otherwise, various quality problems may occur If the adhesive force is too small, it will lead to the loss of pressure sensitive adhesive properties of the plaster cloth, poor adhesiveness of the plaster, easy to loose, and affect the development of the plaster property; and if the cohesion is too small, it may lead to the separation of the plaster from the adhesive layer, the transfer of part of the adhesive to the surface to be adhered, resulting in cleaning difficulties and other disadvantages Jinan Languang mechanical and Electrical Technology Co., Ltd packaging safety testing center has been committed to providing professional material physical performance testing programs and services for global customers, and has accumulated a lot of valuable experience and data in the actual testing If you have any related product quality problems or want to know more details, 400 free or email consultation, we will provide you with technical services wholeheartedly.