Oral dissolving film is generally composed of active drugs, film-forming materials, plasticizers, flavoring agents, surfactants and pigments. The preparation methods usually include casting method and hot melt extrusion method.
Casting method
After the ingredients in the prescription are dissolved or dispersed in a solvent, they are spread on the carrier material and dried to form a film.
Hot melt extrusion
The active ingredient of the medicine is mixed with the thermoplastic film-forming material and other auxiliary materials, heated and extruded, and then cooled to form a film. This method has been used in the plastic industry to prepare films, plates and pipes for hundreds of years. In recent years, it has been gradually used in the pharmaceutical industry to prepare granules, films, tablets, transdermal patches, etc. The method is simple to operate, does not require solvents and water, and disperses poorly soluble drugs.
As a new dosage form, oral dissolving film has certain characteristics as indicators for evaluating its performance.
thickness
The film should have a certain thickness, too thin is not easy to use, too thick will slow down the dissolution. And the uniformity of the thickness reflects the uniformity of the drug content.
Disintegration and dissolution
The film usually dissolves quickly in the oral cavity, so the evaluation of its disintegration and dissolution is very important.
Physical properties
If the strength of the film is too large, there will be discomfort in the mouth during use. The flexibility of the film should also be appropriate. If it is too brittle, it is easy to break; if the toughness is too strong, it is easy to stretch during the preparation and stretching process, resulting in inaccurate dosage.
Taste evaluation
Taste is an important index for evaluating film, and volunteers are usually used for sensory tests. However, the individual differences in sensory tests are large and are affected by the physical condition of the volunteers, making it difficult to obtain an objective evaluation. And it is not suitable for more toxic drugs. The taste sensor can evaluate the taste of medicine objectively.
Mucosal permeability and irritation
The oral mucosal permeability of the membrane can be evaluated by using Franz diffusion cell or flow cell, by measuring the content and rate of the drug passing through the animal's oral mucosa to the receiving cell.
At present, the market share of oral membranes (excluding breath fresheners) is mainly concentrated in the North American market. Japan and South Korea also have better markets. With the promotion of such products in Europe and Asia, it is believed that this dosage form is used in medicine and health care. Both cosmetics and cosmeceuticals have certain commercial potential.