In vivo supersaturation is the behavior of orally administered compounds that undergo supersaturation as they pass through the gastrointestinal (GI) tract. Typically these compounds have a weakly basic nature (pKa in the range of 5 to 8) [1] and a relatively low solubility in aqueous solutions. In vivo supersaturation is a recent phenomenon that was first observed by Yamashita et al. in 2003. [2]
In condensed matter physics and materials science, an amorphous or non-crystalline solid is a solid that lacks the long-range order that is characteristic of a crystal. In some older books, the term has been used synonymously with glass. Nowadays, "glassy solid" or "amorphous solid" is considered to be the overarching concept, and glass the more special case: Glass is an amorphous solid stabilized below its glass transition temperature. Polymers are often amorphous. Other types of amorphous solids include gels, thin films, and nanostructured materials such as glass.
Pharmacology is a branch of medicine, biology and pharmaceutical sciences concerned with drug or medication action, where a drug may be defined as any artificial, natural, or endogenous molecule which exerts a biochemical or physiological effect on the cell, tissue, organ, or organism. More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function. If substances have medicinal properties, they are considered pharmaceuticals.
Solubility equilibrium is a type of dynamic equilibrium that exists when a chemical compound in the solid state is in chemical equilibrium with a solution of that compound. The solid may dissolve unchanged, with dissociation or with chemical reaction with another constituent of the solution, such as acid or alkali. Each solubility equilibrium is characterized by a temperature-dependent solubility product which functions like an equilibrium constant. Solubility equilibria are important in pharmaceutical, environmental and many other scenarios.
Supersaturation occurs with a chemical solution when the concentration of a solute exceeds the concentration specified by the value equilibrium solubility. Most commonly the term is applied to a solution of a solid in a liquid. A supersaturated solution is in a metastable state; it may be brought to equilibrium by forcing the excess of solute to separate from the solution. The term can also be applied to a mixture of gases.
Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly corrosive. It is used to make most fluorine-containing compounds; examples include the commonly used pharmaceutical antidepressant medication fluoxetine (Prozac) and the material PTFE (Teflon). Elemental fluorine is produced from it. It is commonly used to etch glass and silicon wafers.
Ritonavir (RTV), sold under the brand name Norvir, is an antiretroviral medication used along with other medications to treat HIV/AIDS. This combination treatment is known as highly active antiretroviral therapy (HAART). Often a low dose is used with other protease inhibitors. It may also be used in combination with other medications for hepatitis C. It is taken by mouth. The capsules of the medication do not work the same as the tablets.
An ionic liquid (IL) is a salt in the liquid state. In some contexts, the term has been restricted to salts whose melting point is below some arbitrary temperature, such as 100 °C (212 °F). While ordinary liquids such as water and gasoline are predominantly made of electrically neutral molecules, ionic liquids are largely made of ions. These substances are variously called liquid electrolytes, ionic melts, ionic fluids, fused salts, liquid salts, or ionic glasses.
Valnoctamide has been used in France as a sedative-hypnotic since 1964. It is a structural isomer of valpromide, a valproic acid prodrug; unlike valpromide, however, valnoctamide is not transformed into its homologous acid, valnoctic acid, in vivo.
Solid-phase extraction (SPE) is an extractive technique by which compounds that are dissolved or suspended in a liquid mixture are separated from other compounds in the mixture according to their physical and chemical properties. Analytical laboratories use solid phase extraction to concentrate and purify samples for analysis. Solid phase extraction can be used to isolate analytes of interest from a wide variety of matrices, including urine, blood, water, beverages, soil, and animal tissue.
Carvedilol, sold under the brand name Coreg among others, is a medication used to treat high blood pressure, congestive heart failure (CHF), and left ventricular dysfunction in people who are otherwise stable. For high blood pressure, it is generally a second-line treatment. It is taken by mouth.
Biguanide is the organic compound with the formula HN(C(NH)NH2)2. It is a colorless solid that dissolves in water to give highly basic solution. These solutions slowly hydrolyse to ammonia and urea.
Etoperidone, associated with several brand names, is an atypical antidepressant which was developed in the 1970s and either is no longer marketed or was never marketed. It is a phenylpiperazine related to trazodone and nefazodone in chemical structure and is a serotonin antagonist and reuptake inhibitor (SARI) similarly to them.
Sphingosine-1-phosphate (S1P) is a signaling sphingolipid, also known as lysosphingolipid. It is also referred to as a bioactive lipid mediator. Sphingolipids at large form a class of lipids characterized by a particular aliphatic aminoalcohol, which is sphingosine.
Mesoporous silica is a mesoporous form of silica and a recent development in nanotechnology. The most common types of mesoporous nanoparticles are MCM-41 and SBA-15. Research continues on the particles, which have applications in catalysis, drug delivery and imaging.
Nalfurafine is an antipruritic that is marketed in Japan for the treatment of uremic pruritus in individuals with chronic kidney disease undergoing hemodialysis. It acts as a potent, selective, centrally-penetrant κ-opioid receptor (KOR) agonist, and is the first and currently the only selective KOR agonist to have been approved for clinical use. It has also been dubiously referred to as the "first non-narcotic opioid drug" in history.
SB-204070 is a drug which acts as a potent and selective 5-HT4 serotonin receptor antagonist (or weak partial agonist), and is used for research into the function of this receptor subtype.
Vasicine (peganine) is a quinazoline alkaloid. It is found in Justicia adhatoda, after which it is named. It is additionally found in Peganum harmala.
Deoxygedunin, or 14,15-deoxygedunin, is a naturally occurring tetranortriterpenoid isolated from the Indian neem tree, a plant that has been used in India since ancient times as a remedy for various ailments. Deoxygedunin has been found to act as a potent, selective, small-molecule agonist of TrkB, the main receptor of brain-derived neurotrophic factor (BDNF). It produces TrkB-dependent neurotrophic and neuroprotective effects in mice and enhances learning processes. In addition, deoxygedunin evokes rapid TrkB-dependent antidepressant-like effects in the forced swim test, an animal model of depression, similarly to 7,8-dihydroxyflavone (7,8-DHF) and ketamine, and notably with a greater potency than 7,8-DHF. The compound was discovered by the same group that identified 7,8-DHF and N-acetylserotonin as TrkB agonists.
11α-Hydroxyprogesterone (11α-OHP), or 11α-hydroxypregn-4-ene-3,20-dione is an endogenous steroid and metabolite of progesterone. It is a weak antiandrogen, and is devoid of androgenic, estrogenic, and progestogenic activity. It was investigated as a topical antiandrogen for the treatment of androgen-dependent skin conditions in the early 1950s, and was found to produce some benefit. In 1995, 11α-OHP, along with its epimer 11β-hydroxyprogesterone, was identified as a very potent competitive inhibitor of both isoforms (1 and 2) of 11β-hydroxysteroid dehydrogenase (11β-HSD). It is notably not metabolized by 11β-HSD2. 11α-OHP is a more potent inhibitor of 11β-HSD than enoxolone (glycyrrhetinic acid) or carbenoxolone in vitro (IC50 = 0.9 nM; IC50 = 5 nM in transfected cells). The compound has been found to be highly active in conferring mineralocorticoid sodium-retaining activity of corticosterone in vivo in rat bioassays and in increasing blood pressure, effects that it mediates by preventing the 11β-HSD-mediated inactivation of endogenous corticosteroids. Because of its inhibition of 11β-HSD and consequent potentiation of corticosteroids, 11α-OHP has recently been patented for the treatment of skin diseases, particularly psoriasis in combination with clobetasol propionate and minoxidil.