(2) Casting coating step: after that the entire material had cooled to about 25° C. and there were no fine bubbles by observation, a measuring cup or other tool was used to take and pour the material onto an appropriate position of a coating table; a reasonable coating height was set to be about 800 μm, and the coating speed was set to be 1 mm/min for coating.

(3) heating and cutting process: after the coating, the film was heated at an ambient temperature of 25° C. and a humidity of 50% to 65%, and the heating temperature was 60° C. to 65° C., and the heating time duration was 40 to 90 minutes; the heating was finished based on the properties of the film; then, a food-grade cutting knife or grinding tool was used to cut the film to an appropriate size of 2 cm× (1-3) cm, and the product was subjected to package and storage.

3. Test and Evaluation Methods for the Oral Soluble Film:

After the tests and sensory evaluation on commercial product and the products of the present application, the oral soluble film is determined to be suitable for cutting and packaging processes and able to provide a good attachment sensation. The physical and chemical properties of the oral soluble film are shown in Table 2.

TABLE 2

Items
Technical standard

Mass percentage of moisture
7%-13%

Tensile strength
6 N/mm²-20 N/mm²

Breaking elongation percentage
>30%

Adhesion force
1 N/cm²-3 N/cm²

Mass percentage of API (single piece)
1%-10%

Dissolving time limit in vitro
20 min to 45 min

Dissolving time of 80% API
5 min-10 min

4. Test Method:

Moisture: the mass percentage of the entire oral soluble film was tested according to the Karl Fischer method;

Thickness: a sample of the oral soluble film was taken, and the outer packaging was removed; points in the middle and four edges of the oral soluble film were selected, and the thickness at each point was measured by a micrometer, and the average thickness value was calculated (five-point-method).

Weight: a sample of the oral soluble film was taken, and the outer packaging was removed; a tweezer was used to clamp the entire oral soluble film, and the oral soluble film was placed on an electronic balance to record the weight; the weights of 10 samples were measured as mentioned above, and the mean and variance values were calculated accordingly.

Tensile strength: the oral soluble film was clamped by two clamps with rubber or cotton pads to avoid cutting of the oral soluble film, and the oral soluble film was fixed on the clamping position of the TA-XT2 texture analyzer; a distance between the two clamps was set to be less than the length of the oral soluble film; the upper clamp was moved upward at a speed of 20-120 mm·min⁻¹until the oral soluble film breaks; the tensile strength TS (MPa), i.e., a maximum stress applied onto the film, was calculated by the formula: TS=F_max/A, A=t×s, wherein F_maxdenotes the maximum force when the oral soluble film breaks (N), A denotes the initial cross-sectional area of the oral soluble film (mm²), t denotes the thickness of the oral soluble film, and s denotes the width of the oral soluble film.

Breaking elongation percentage: the oral soluble film was clamped by two clamps with rubber or cotton pads to avoid cutting of the oral soluble film, and the oral soluble film was fixed on the clamping position of the TA-XT2 texture analyzer; a distance between the two clamps was set to be less than the length of the oral soluble film; the upper clamp was moved upward at a speed of 20-120 mm min⁻¹until the oral soluble film breaks; the breaking elongation percentage (L %) was by the formula: L %=100×(L_max/L−1), wherein L_maxis the distance between the two clamps when the oral soluble film breaks (mm), and L is the initial distance between the two clamps (mm).

Adhesion force in vitro: two rubbers were fixed on the end portion and the base of the tension meter, respectively; a sample of the oral soluble film was taken, and the outer packaging was removed; the length L and width W of the oral soluble film were measured; artificial saliva of 50 μl was taken to moisten the surface of the rubber; the oral soluble film was attached to the surface of the rubber, ensuring that the length and width of the rubber were greater than the length and width of the oral soluble film, respectively; the oral soluble film was flattened, and the surface of another rubber moistened with artificial saliva of 50 μl was placed onto the oral soluble film; an object of 2 kg was used to press the oral soluble film with the two rubbers for 90 s, and then the object was removed; the wheel was rotated to separate the two rubbers within 5 s, and the peak value displayed by the tension meter was the maximum adhesion force of the oral soluble film (F_max); the adhesion force was calculated by the formula: F=F_max/S, S=L×W, wherein F_maxdenotes the maximum force of the oral soluble film (N), S denotes the initial area of the oral soluble film (cm²), L denotes the length of the oral soluble film, and W denotes the width of the oral soluble film.

Dissolving time limit: artificial saliva of 100 mL was placed into a beaker, and the beaker was placed on an electromagnetic stirrer; the beaker was heated by a 37° C. constant temperature water bath with a stirring speed of 130 r/min; an oral soluble film was flattened on a grid, the grid was plated on a bracket and hanged on the artificial saliva, ensuring that the artificial saliva contacts but does not fully infiltrate the oral soluble film; the dissolving time of the oral soluble film (T) was recorded.

Test of active components: an oral soluble film was weighed and completely dissolved in artificial saliva of 100 mL; an appropriate reagent kit, liquid chromatography, and other method was used to measure the active components; the content of the active components was calculated by the formula: 100×content of components×100 mL.

Dissolving curve: an oral soluble film was placed on a mesh carrier and suspended on the beaker containing artificial saliva of 100 mL, ensuring that the oral soluble film was infiltrated by the artificial saliva; the beaker was placed on a temperature-controlled magnetic stirrer, the stirring speed was set to be 130 r/min and the temperature was set to be 37° C.; after specified time durations such as 0.5 min, 1 min, 2 min, 3 min, 5 min, 8 min, 12 min, 18 min, 25 min, and 35 min, the sample of 100 μL was collected and the content of the active components therein was measured; the dissolving rate of the active components was calculated, and a curve of the dissolving characteristics of the active components was drawn based on the content of the active components.