Primidone (link:https://www.bloomtechz.com/synthetic-chemical/api-researching-only/primidone-powder-cas-125-33-7.html) is an antiepileptic drug that belongs to isoprene compounds with a molecular formula of C12H14N2O2 and a molecular weight of 218.26. It is white or light yellow crystal powder, odorless and tasteless. Almost insoluble in water, but easily soluble in chloroform, benzene, ethanol, acetone and other organic solvents. Under alkaline or acidic conditions, it is easily hydrolyzed. Relatively stable, not easily affected in dry air. Under the action of strong acid, strong alkali, oxidant, ozone, ultraviolet radiation, etc., it is easy to decompose and degrade. It has certain toxicity and can cause poisoning and death. Relevant safety and protection measures need to be followed during preparation, storage and use.
Chemical properties of Primidone.
1. Acidity and Alkalinity
Primidone is a weakly basic compound with a pKa value of about 7.0-7.5. Under acidic conditions, Primidone is easily hydrolyzed to generate the main metabolites phenobarbital and phenylethylmalonamide (PEMA). Under alkaline conditions, Primidone is prone to sodium lauryl sulfate-ethanol extraction to obtain its free alkaline state. In addition, Primidone can also have acid-base reactions with some drugs or ingredients, affecting their absorption and metabolism.
2. Redox
Primidone itself is not prone to redox reactions. However, under the action of some oxidants, such as hydrogen peroxide, hydrogen peroxide, chromic acid, etc., Primidone is prone to oxidation reaction and generates corresponding oxidation products. In addition, under reducing conditions, Primidone is prone to hydrolysis and generates phenobarbital and PEMA.
3. Esterification reaction
Primidone contains two carboxyl functional groups and a C—O—C linked ester group, so it is prone to esterification. Primidone can react with some alcohol compounds to generate corresponding Primidone esters, and these esterified products may have antiepileptic activity.
4. Electrophilic addition reactions
Primidone contains an unsaturated bond, so electrophilic addition reactions can occur. Under the action of some electrophilic reagents, such as halogen, nitro, carboxyl, etc., Primidone is prone to addition reaction to generate corresponding addition products.
5. Amination reaction
Primidone contains an amino functional group, so it is prone to amination reaction. Under the action of some amino reagents, such as ammonia water, ethylenediamine, etc., Primidone is prone to amination reaction and generates corresponding amination products.
6. Photochemical reactions
Primidone is easily affected by ultraviolet radiation. In photochemical reactions, Primidone is prone to cracking or wheel addition reactions to generate corresponding photochemical products.
In short, Primidone is a compound with various chemical properties such as acidity and alkalinity, redox property, esterification reaction, electrophilic addition reaction, amination reaction, and photochemical reaction. Special attention should be paid to safety and protection measures during preparation, storage and use.
The molecular structure of Primidone contains a five-membered heterocyclic ring (2,4-diazacyclohexanone ring), two methyl groups and one ethoxy group. The "C" in its molecular formula represents carbon, which acts as a link in Primidone's molecular structure, while the "H" represents a hydrogen atom, which maintains the molecular integrity. In addition, "N" represents a nitrogen atom, "O" represents an oxygen atom, and "E" represents an ethoxy group.
The molecular structure of Primidone can be described by several methods, the most common of which are the use of linear and molecular orbital diagrams. In a linear structure, each atom of the molecular chemical formula is connected to form a molecular chain according to the bonding relationship between the atoms in the molecule. The molecular orbital diagram shows the orbital interactions between carbon and nitrogen atoms and the distribution of electron clouds, thus revealing the chemical properties and reaction methods inside the Primidone molecule.
Primidone is a drug widely used to treat epilepsy and tremors. Understanding the pharmacokinetic properties of Primidone is important for optimizing its use and monitoring its safety. The pharmacokinetic properties of the drug include absorption, distribution, metabolism, and excretion. The following is a detailed introduction:
1. Absorption:
Primidone is an oral drug that is absorbed from the gastrointestinal tract. The rate and extent of its absorption vary from individual to individual. Under normal circumstances, Primidone is fully absorbed in the gastrointestinal tract, but the speed and extent of its absorption are reduced after meals. Therefore, patients are advised to take Primidone 2 hours before or after meals.
In addition to oral administration, Primidone can also be given intramuscularly or intravenously, but this is rarely used.
2. Distribution:
Primidone is widely distributed in the body, mainly in liver, muscle, kidney and brain tissue. It can also cross the blood-brain barrier, enter the central nervous system, and reach similar concentrations in the brain tissue as in the blood. Its distribution characteristics are mainly determined by the molecular structure and physiological properties of the drug.
3. Metabolism:
Primidone is metabolized in the body into Phenobarbital and some other active metabolites. This process mainly occurs in the liver and is related to the CYP450 enzyme system. Phenobarbital is an ancient sedative drug that has been widely used in antiepileptic therapy. It exerts its antiepileptic effect mainly by enhancing the function of GABA A receptor, thereby reducing the excitability of neurons and controlling the occurrence of epileptic seizures.
The rate of metabolism and excretion of Primidone varies with individual differences. Pregnant women, people with epilepsy, infants, and the elderly often have slower metabolic rates than healthy people. In addition, many factors, such as liver function and the influence of other drugs, etc. may also affect the metabolic rate of Primidone.
4. Excretion:
Primidone and its metabolites are primarily excreted by the kidneys. The half-life of Primidone is 8-24 hours, and the excretion time will vary according to factors such as the patient's renal function and metabolic rate. In patients with impaired renal function, the rate of excretion may be decreased, thereby increasing the plasma concentration of the drug and the risk of toxic side effects.
In short, Primidone is an oral drug, which is mainly metabolized and excreted through liver metabolism and renal excretion. Its absorption, distribution, and excretion processes are affected by many factors, such as physiological characteristics, metabolic rate, and liver function. Understanding the pharmacokinetic properties of Primidone is very important for formulating a reasonable medication regimen and monitoring drug efficacy and risk.
The history of Primidone's discovery began in the 1940s, when a doctor named Schechter first noticed that the compound might have the effect of treating epilepsy and tremors.
In 1949, American pharmacist and neuroscientist Sidney Udenfriend and others synthesized Primidone for the first time, and found that it had sedative and anticonvulsant effects in animals. Since then, Primidone began to enter the clinical trial stage, and was finally confirmed to have an effective control effect on almost all types of epilepsy, and gradually became one of the mainstream antiepileptic drugs.
The following is a detailed description of the history of Primidone's discovery:
1. Early exploration:
Primidone was synthesized by Sidney Udenfriend and colleagues in the early 1940s. At the time, they were searching for new antiepileptic drugs to treat this common neurological disorder. This is a very difficult task because there are many types of epilepsy and they respond differently to different drugs.
During the quest, Udenfriend used a compound called "promethazine" to create a new anti-epileptic drug. He noticed that the compound had anticonvulsant and sedative effects in animals, but the effects were not very satisfactory.
So Udenfriend and his colleagues set out to synthesize promethazine-like compounds and test them. Among them, Primidone is one of the compounds finally found to have antiepileptic effect.
2. The first clinical trial:
In 1949, Udenfriend et al. used Primidone for the first time in human clinical trials to evaluate its efficacy on epilepsy. It was found that Primidone is effective in controlling almost all types of epilepsy with relatively few side effects.
However, the research at that time was limited to small-scale trials and case reports, and more research is needed to prove the effectiveness and safety of Primidone. Some studies have shown that Primidone may have more side effects than other antiepileptic drugs, such as dizziness, fatigue, and abnormal mental reactions.
This has led to a limited use of Primidone, which can only be used under strict observation and monitoring.
3. Follow-up research:
Over the next few decades, many researchers conducted further studies on Primidone to evaluate its efficacy and safety against epilepsy and tremors.
Some studies have shown that Primidone is effective in reducing the frequency of seizures in epilepsy, and may work better in people with certain types of epilepsy. In addition, Primidone has also been proven to be used to control the onset of tremors, such as the fine tremors of Parkinson's disease.
However, side effects of Primidone remain an important concern. In addition to the previously mentioned side effects, severe side effects have also been reported, such as leukopenia, abnormal liver function, etc. These findings led to further restrictions on the use of Primidone.
Over time, other antiepileptic drugs gradually replaced Primidone. However, Primidone is still regarded as one of the effective drugs for the treatment of epilepsy and tremor, and is still widely used in some specific cases.
Summarize:
Primidone is an effective anti-epileptic and anti-tremor drug, originated in the 1940s, synthesized by Sidney Udenfriend et al., and proved its therapeutic effect on epilepsy and tremor through clinical trials. However, the side effects and limitations of Primidone are becoming more and more obvious, causing other antiepileptic drugs to gradually replace it. Nevertheless, Primidone is still regarded as one of the important drugs in the treatment of epilepsy and tremor, providing patients with an effective treatment option.