Chinese Pharmacopoeia 2020 Edition - Determination of Initial Viscosity

 Chinese Pharmacopoeia 2020 Edition - Determination of Initial Adhesion: This method is used to measure the adhesive force of the plaster and the skin surface after the patch is applied to the skin
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In this method, four indexes of initial adhesion, holding force, peeling strength and adhesive force are used to measure the adhesive force of plaster and patch
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The initial adhesive force refers to the adhesion force of the plaster, the adhesive surface of the plaster and the skin to the skin when in contact with the skin under slight pressure, that is, the peeling resistance generated under the condition of slight pressure contact; The ability of the body to resist deformation or breakage caused by persistent external force; peel strength means the peeling resistance of the plaster, the paste of the plaster and the skin; the adhesive force means that the plaster, the sticky surface of the plaster and the skin are attached to the skin.
of adhesion
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The first method (measurement of initial adhesive force) Unless otherwise specified, the initial adhesive force of the sound patch and the patch is measured by the rolling ball ramp stop method
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Roll the appropriate series of steel balls in the following table over the viscous surface of the test product placed on the inclined plate respectively, and evaluate the initial viscosity according to the largest number of steel balls that the viscous surface of the test product can stick to
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1
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The test device is mainly composed of inclined plate, base, stainless steel ball and ball receiving box (Fig.
1).
The inclined plate (the inclination angle is 15°, 30" or 45°) is made of stainless steel with a thickness of about 2mm.
Trace board
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There are two horizontal lines separated by 10mm on the board.
The mark for the starting position of the steel ball is the mark for fixing the test sample: the base should be able to adjust and maintain the horizontal state of the device; the ball box is used for The inner wall of the steel ball that rolls off the connecting plate should be lined with soft material; the size and specification of the stainless steel ball should meet the requirements in the table
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> Place for more than 2 hours under the conditions of 18-25C and relative humidity of 40%-70%
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Scrub the surface of the inclined plate and the stainless steel ball with a wiping material dipped in absolute ethanol, and dry it carefully with a clean lint-free cloth.
Repeat the cleaning for more than 3 times until the surface of the inclined plate and the stainless steel ball is clean by visual inspection
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 Adjust the inclined plate according to the inclination angle specified under each category, take 3 pieces of the test product, and fix the backing of the test product on the inclined plate with double-sided tape respectively.
The upper end of the test product should be located on the horizontal line of the inclined plate.
position, the sticky side is up and the length of the experiment along the slope direction is not more than 5cm, and the test sample should be flat on the board
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Place the steel balls specified under each category on the horizontal line and fall freely from the inclined plane
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3.
Judging from the results, if 3 of the steel balls adhered to each of the test samples are the largest steel ball number or 2 are the largest steel ball ball number, and the other steel ball ball number is only one size smaller, it is in line with the standard.
Regulations: If one is the largest steel ball, and the other two steel balls are only one smaller, then three additional pieces should be taken for retesting, and all three pieces can stick to the largest steel ball to meet the requirements
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