Preparations for rectal use
Preparations for rectal use (Latin Rectalia) is the name of a monograph in the European Pharmacopoeia . The monograph defines the quality requirements for medicinal preparations that are used for the local or systemic administration of drugs in or through the rectum . Rectal preparations are used in particular when peroral application is not possible because, for example , the patient is unconscious or cannot swallow. Furthermore, the rectal application can circumvent the first-pass effect in the liver and the active ingredient cannot be destroyed by gastric acid . Because of their increased surface wetting , rectal foams are used particularly in the local treatment of chronic inflammatory bowel diseases .
Classification
The European Pharmacopoeia divides the "preparations for rectal use" into:
- Suppositories
- Rectal capsules
- Rectal solutions, emulsions and suspensions
- Powders and tablets for making rectal solutions or suspensions
- Semi-solid preparations for rectal use
- Rectal foams
- Rectal tampons
Rectal capsules
A rectal capsule is a solid, single-dose pharmaceutical dosage form that is introduced into the rectum and there releases the active ingredient it contains. The capsule generally corresponds to a soft capsule . Thus this consists mostly of gelatin , plasticizers, water and dyes or pigments. A suitable white pigment is, for example, titanium dioxide , iron oxides are suitable as color pigments, and chlorophyll is suitable as a dye. Glycerol or sorbitol are often used as plasticizers . The capsule has an elongated shape and a smooth surface, which is intended to facilitate insertion. The shape is generally similar to that of suppositories. In addition, the capsule can be provided with a coating which is also intended to facilitate insertion. Overall, the capsule should have a uniform appearance. The capsules can also have an altered release of active ingredient or achieve a prolonged local effect. The examination of important quality features such as the disintegration time - unless a changed effect or a prolonged effect is to be achieved - or otherwise the release of the active ingredient or ingredients are prescribed by the pharmacopoeia.
Rectal foams
Rectal foams are a form of administration with which active ingredients can be administered rectally. In particular, the reduced urge to defecate and a greater degree of wetting of the rectum surface are advantages over suppositories. Rectal foams are mainly used in the treatment of chronic inflammatory bowel diseases. The two best-known finished medicinal products that are sold as rectal foam are the Budesonide- containing Budenofalk and the mesalazine- containing Salofalk .
The pharmacopoeia stipulates the relative foam density and the expansion time for testing the foams. Rectal foams must also comply with the pharmacopoeia monograph “ Foams containing active ingredients ”.
Rectal solutions, emulsions and suspensions
Rectal solutions, emulsions (rarely used) and suspensions are liquid dosage forms that are intended for use in enemas ( instillation ), for example, in the case of chronic inflammatory bowel diseases or as laxatives . Here, the active ingredient contained is either dissolved or dispersed in water or other suitable liquids such as glycerol or polyethylene glycol . The liquid rectal drug forms are usually single-dose drug forms with volumes in the range from 2.5 to 2000 ml. The containers are usually bottles or bags that are designed so that the preparation can be introduced into the rectum. Optionally, a suitable applicator, such as a microclysma , can be added to the drug . This is a small cannula or enema that is inserted into the rectum and which can be used to introduce small amounts of fluid into the rectum. The liquid preparations for rectal use can also be prepared by dissolving or dispersing powders and tablets.
Rectal tampons
Rectal tampons are designed to be used in the lower part of the rectum for a limited period of time. They consist of a suitable carrier material such as cellulose , which is shaped like a suppository and has been impregnated with active ingredient. Alternative carrier materials are, for example, collagen or silicone . The rectal tampons can be provided with a gauze insert that fixes the active ingredient at the exit of the anal canal and thus achieves a high local effectiveness of the active ingredient. Examples of indications for rectal tampons include anal eczema and hemorrhoidal diseases . The label must indicate the amount of active ingredient or ingredients in relation to one tampon.
Individual evidence
- ↑ European Pharmacopoeia 9th Edition | EDQM - European Directorate for the Quality of Medicines. In: www.edqm.eu. Retrieved January 10, 2017 .
- ^ Deutscher Apotheker Verlag (ed.): European Pharmacopoeia, 8th edition . 1st edition. Deutscher Apotheker Verlag, Stuttgart 2014, ISBN 978-3-7692-6512-5 .