ChemicalBook > Product Catalog > Biochemical Engineering > Inhibitors > Metabolism > PDE inhibitors > Sildenafil citrate
Sildenafil citrate Chemical Properties
- Melting point:187-189°C
- storage temp. Desiccate at RT
- solubility DMSO: >20mg/mL
- form white powder
- Water Solubility 3.488g/L(temperature not stated)
- Merck 14,8489
- Stability:Store in Freezer
- CAS DataBase Reference171599-83-0(CAS DataBase Reference)
Sildenafil citrate Usage And Synthesis
- Chemical PropertiesWhite Solid
- UsesAn orally active selective type 5 cGMP phosphodiesterase inhibitor
- UsesEnzyme inhibitor
- DefinitionChEBI: The citrate salt of sildenafil.
- brand nameViagra (Pfizer).
- Biological ActivityOrally active, potent inhibitor of phosphodiesterase 5 (PDE5) (IC 50 = 4 nM). Enhances nitric oxide-dependent relaxation of human corpus cavernosum in vitro .
- Safety ProfileA poison by ingestion. Human systemic effects. When heated to decomposition it emits toxic vapors of NOx and SOx.
- Veterinary Drugs and TreatmentsSildenafil may be of benefit in the adjunctive treatment of pulmonary
hypertension in small animals.
In humans, sildenafil is indicated for erectile dysfunction or pulmonary hypertension.
- structure and hydrogen bondingSildenafil citrate (SC) has been widely used for the treatment of erectile disorder. A detailed study concerning solid-state structure of this compound is very important for understanding enzyme (PDE5)-inhibitor (sildenafil) interaction. It is also of interest to determine sildenafil’s protonation sites, as they may be responsible for its binding to the phosphodiesterase acidic amino acids.
Sildenafil citrate (Viagra) and sildenafil base in pure form were characterized by 1H, 13C, 15N NMR spectroscopy in solution, solid-state, and pharmaceutical dosage forms.42 The analysis of chemical shifts showed that: (i) N6-H forms intramolecular hydrogen bonds, (ii) N25 is protonated in the salt, and (iii) intermolecular OH. . .N hydrogen bonds involving N2 and N4 are present in the solid sildenafil citrate. The 13C CPMAS spectra of the tablets containing different amounts of sildenafil citrate were recorded and showed that chemical shifts of sildenafil citrate in pure form and in pharmaceutical dosage forms are the same. SC is easily detected in the pharmaceutical dosage forms since only two of its carbon resonances (OCH2 and quaternary carbon of the citrate anion) fall into carbohydrate-type region of the excipient.
Solid-state 13C and 15N MAS NMR have recently been used to investigate how water interacts with SC.43 When the humidity is altered, the water concentration in the solid compound changes but does not reach a stoichiometric (e.g., 1:1) ratio to form a true hydrate. Only one set of 15N and 13C signals was observed for each humidity level indicating that water incorporated into the crystal lattice of SC is very mobile and exchanges rapidly between various sites. The 13C data showed the formation of a hydrogen bond between water molecule and one carbonyl of the citrate anion. The spectra also show that the water content affects the conformation of the propyl group. Additionally, 15N dipolar dephasing (DD) experiments confirmed that the sildenafil molecule is only protonated in the piperazine ring.
- Company Name:Guangzhou Jianbei Biotechnology Co., Ltd Gold
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