Hydrochlorides are salts consisting of organic bases that react with hydrochloric acid. Thus, hydrochlorides also belong to the amines of primary, secondary and tertiary nature. A typical feature of hydrochlorides is that they undergo a neutralization reaction with hydrochloric acid. Due to their chemical properties, hydrochlorides form a popular additive in numerous drugs.
What are hydrochlorides?
Hydrochlorides basically represent salts consisting of organic bases as well as hydrochloric acid. In the course of a chemical reaction, the bases neutralize with the hydrochloric acid. The typical reaction for the formation of hydrochlorides is similar to the formation process of ammonium chloride, whereby ammonia and hydrochloric acid react with each other. In principle, all hydrochlorides have a chloride atom and for this reason belong to the salts. The parent compounds of hydrochlorides are in most cases amines. However, unlike amines, hydrochlorides are generally much more soluble in water. In addition, hydrochlorides can be purified more easily, using recrystallization. Hydrochlorides, which belong to the amines, are characterized by higher stability and age considerably more slowly. The resistance to degradation is particularly evident in the color of the hydrochlorides. These advantages of hydrochlorides are particularly noticeable in comparison with amines, which are free and basic. Chemistry divides hydrochlorides into monohydrochlorides and dihydrochlorides, among others. Monohydrochlorides are formed mainly from di- and triamines as a result of a reaction with hydrochloric acid. In contrast, dihydrochlorides are formed when organic diamines react with an excess of hydrochloric acid. Typical dihydrochlorides include meclozine, arsphenamine and sapropterin. In addition, hydrochlorides belong to the hydrohalides. Other representatives of this category of chemical substances are, for example, hydrobromides and hydrofluorides.
Pharmacological effects on the body and organs
Hydrochlorides are characterized by very good solubility in water and high bioavailability in the human organism. For this reason, they are used in numerous medical drugs to increase the effectiveness of the corresponding drugs. Pharmaceutical manufacturers produce the drugs directly in the form of hydrochlorides. The readily water-soluble hydrochlorides facilitate the production of aqueous medications and solutions, such as drops for the eyes, injection solutions and nasal sprays. Solubility in water also plays a decisive role in the case of orally administered drugs, since the stomach and intestines only absorb the active ingredients if they are suitably soluble in water. The active substances dissolve from the tablets or dragées so that absorption is subsequently possible. This means that the drugs pass more quickly into the bloodstream. Properties such as the high stability and good processing possibilities of hydrochlorides are also relevant for their extensive use in the manufacture of medicines. Currently, hundreds of different hydrochlorides are regularly used in pharmaceuticals. Particularly popular and highly demanded hydrochloride-based drugs include ambroxol as well as metformin.
Medical application and use for treatment and prevention.
Hydrochlorides are used in a wide range of medicines, improving or in some cases enabling the absorption capacity of the active ingredients through their typical properties. The crucial aspects for the use of hydrochlorides in the production of drugs are their stability and water solubility. On the one hand, these aspects facilitate the production of aqueous solutions such as drops or sprays. On the other hand, hydrochlorides improve the absorption capacity of active ingredients that patients take in the form of solid tablets or capsules. The European Pharmacopoeia currently lists around 200 hydrochlorides used in pharmaceutical production. The Pharmaceutical Substances Catalogue even includes over 1,000 different hydrochlorides. Hydrochlorides are particularly popular for use in the production of the drugs ambroxol and metformin, both of which are in high demand.
Risks and side effects
The side effects of hydrochlorides depend primarily on the particular drug for whose manufacture they form the basis.Hydrochlorides are frequently used, for example, in the drugs ambroxol and metformin. Ambroxol is a drug used to treat coughs associated with tough mucus that is firmly lodged in the airways. Hydrochlorides form the basis for this active substance and its absorption into the blood. Possible side effects include general discomfort such as nausea, vomiting, and diarrhea, as well as pain in the abdomen. Some individuals experience hypersensitivity reactions such as skin rashes, itching, shortness of breath, and swelling of the face. Sometimes patients develop fever and chills. Rarely, symptoms such as toxic epidermal necrolysis, Stevens-Johnson syndrome or erythema multiforme appear. Hydrochlorides also form the basis of the drug metformin. Doctors prescribe the drug primarily to treat type 2 diabetes mellitus. Potential side effects include digestive tract complaints. Some people develop symptoms such as nausea, diarrhea, abdominal pain or vomiting. In addition, taste perception sometimes changes, causing some patients to lose their appetite. In rare cases, individuals experience lactic acidosis after ingestion. This manifests itself in aching muscles, gastrointestinal complaints and cramps. The hydrochlorides themselves are far less responsible for the side effects that occur than the actual active ingredients of the drugs in which they are used. During the development of drugs, pharmaceutical manufacturers check whether there are any undesirable interactions between the hydrochloride used and the active ingredient.
