The short version of Karl Fischer titration fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-09-22. Anything still debated is marked as such rather than presented as settled.
In aqueous solution, creatine monohydrate exists mainly as a zwitterion, carrying both a positive guanidinium charge and a negative carboxylate charge. This charge separation raises water solubility relative to many neutral organic solids and helps explain its behavior in analytical separations. The monohydrate can lose its water of crystallization under sustained heat or low humidity, converting toward anhydrous creatine. Such transitions matter for mass balance calculations because the hydrate contributes water mass that is not part of the active creatine molecule.
The term creatine monohydrate is often shortened to creatine in casual usage, though other creatine forms exist, including citrate, nitrate, and hydrochloride salts. These alternative forms differ in solubility, pH behavior, and the amount of creatine delivered per unit mass. Regulatory categories vary by country: some jurisdictions treat it as a food ingredient, while others place it under supplement or drug frameworks depending on claims and presentation. Standard reference texts list it as a naturally occurring nitrogenous organic acid rather than a vitamin or mineral.
Quality control of creatine monohydrate relies on a combination of identity, purity, and moisture tests. High-performance liquid chromatography with ultraviolet detection is widely used to separate creatine from creatinine and other related nitrogenous compounds. Spectroscopic methods such as infrared and nuclear magnetic resonance provide structural confirmation. Because the material is a hydrate, water content is measured separately, often by Karl Fischer titration. These tests together establish whether a lot meets a defined specification.
Manufacturing processes can leave trace amounts of dicyandiamide, creatinine, or residual solvents, depending on the synthetic route and purification steps. Heavy metals, arsenic, and microbial contamination are also monitored for food or pharmaceutical grades. Particle size distribution can affect dissolution behavior and blending uniformity, so it may be specified for certain applications. Analytical results are reported on a dry basis or as-is basis, and the difference matters when comparing certificates of analysis. Open questions remain about how minor impurities influence long-term stability under varied storage conditions.
Stability studies typically examine the effects of temperature, humidity, and light on creatine monohydrate. Sealed containers stored in cool, dry conditions help limit moisture uptake and hydrolysis. Elevated temperature and high relative humidity can accelerate conversion to creatinine, especially in aqueous solutions. In solid dosage forms, excipients and processing steps may also affect stability. Published stability data are not fully consistent across studies because test conditions and analytical methods vary.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C4H11N3O3·H2O | Hydrated form includes one water molecule per creatine unit. |
| Molar mass | 149.15 g/mol | Calculated for the monohydrate form. |
| Appearance | White crystalline powder | Common commercial grade is odorless or nearly odorless. |
| Solubility in water | Moderately soluble | Solubility increases with temperature and depends on pH. |
| Common synonyms | Creatine hydrate; N-methylguanidinoacetic acid | Monohydrate distinguishes it from anhydrous creatine. |
In April 2019, Rolling Stone ranked the album at No. 6 on its list of the "50 Greatest Grunge Albums". In 2024, Loudwire staff elected it as the best hard rock album of 1992. In 2025, Em Casalena of American Songwriter included the album in the site's list of "4 Grunge Albums That Are Way Better Than Nevermind".
=== Therapeutics === The small size and stability profile of Affimers combined with their human origin confer drug-like properties. This may represent advantages over antibodies in terms of tissue penetration, for example in solid tumours where Avacta are developing PD-L1 inhibitors as alternatives to Opdivo and Yervoy, though requires half life modification to prevent rapid excretion through the kidney. Affimers can be conjugated to form multimers for the design of therapeutics. Examples include the production of multi-specific Affimer molecules to albumin binders to increase their half-life in vivo and for use as the targeting moiety in chimeric receptors or modified to carry a toxin in Affimer-drug conjugates. Affimers as therapeutics are in discovery and preclinical development to tackle cancer, both via CAR-T cell therapy and as checkpoint inhibitors. Early studies using ex vivo human samples showed low immunogenicity associated with the Affimer scaffold, at levels comparable to a marketed antibody therapeutic. Furthermore, initial preclinical studies showed good efficacy and tolerability of the anti-PDL1 immuno-oncology Affimers in mice. It is anticipated that IND filing for the first Affimer therapeutic will occur in 2023.
On 14 February 2003, the appeals court overturned the verdict, finding that Akre was not a whistleblower because of the Florida "legislature's requirement that agency statements that fit the definition of a "rule" (must) be formally adopted (rules). Recognizing an uncodified agency policy developed through the adjudicative process as the equivalent of a formally adopted rule is not consistent with this policy, and it would expand the scope of conduct that could subject an employer to liability beyond what Florida's Legislature could have contemplated when it enacted the whistle-blower's statute."
Sources: en.wikipedia.org
Pregnancy Previous angioedema associated with ACE inhibitor therapy Bilateral renal artery stenosis Hypersensitivity to ACE inhibitors Impaired renal function Aortic valve stenosis or cardiac outflow obstruction Dehydration (hypovalemia) ACE inhibitors should be used with caution in people with hemodialysis with high-flux polyacrylonitrile membranes.
=== Stress === Smokers report higher levels of everyday stress. Several studies have monitored feelings of stress over time and found reduced stress after quitting. The deleterious mood effects of everyday between-cigarette nicotine withdrawal symptoms explain why people who smoke experience more daily stress than non-smokers, and become less stressed when they quit smoking. Deprivation reversal also explains much of the arousal data, with deprived smokers being less vigilant and less alert than non-deprived smokers or non-smokers. Recent studies have shown a positive relationship between psychological distress and salivary cotinine levels in smoking and non-smoking adults, indicating that both first-hand and second-hand smoke exposure may lead to higher levels of mental stress.
=== 27 April === A Moscow court fined the Wikimedia Foundation, the hosting platform for Wikipedia, two million roubles. This is the seventh fine since 2023 by a Russian court. The latest fine was for a failure to remove an article from Wikipedia that contains "classified military information" about the war in Ukraine. Russian digital affairs minister Maksut Shadaev told Interfax "We are not blocking Wikipedia yet, there are no such plans for now." Jens Stoltenberg, Secretary General of NATO, announced that since the start of the war NATO had provided Ukraine with anti-aircraft weapon systems, some MiG-29 aircraft, 230 tanks and 1550 other armored vehicles, which makes up 98% of the previously promised aid in armored vehicles. He said that NATO had trained enough Ukrainians to assemble 9 new armored brigades, which put Ukraine in a strong position to recapture occupied territories. Melitopol's chief of police, Oleksandr Mishchenko, was killed by an Improvised explosive device. He had been collaborating with the Russian forces since they captured the city. Another police officer was killed and one more wounded. The attack was blamed on Ukrainian partisans. It was reported that a military projectile had been discovered in a forest close to the village of Zamosc near Bydgoszcz, Poland. It was later identified as a Russian Kh-55 missile. According to Finnish Foreign Minister Pekka Haavisto, the Russian Central Bank had frozen the bank accounts of the Finnish Embassy in Moscow and the Finnish consulate in Saint Petersburg.
Sources: en.wikipedia.org
=== Anti-degradation === Many biological agents and chemical compounds have been used in order to prevent matrix-degrading enzymes that actively work to degrade cartilage. Monoclonal antibodies, most commonly studied being 12F4.1H7, work to specifically suppress ADAMTS-5-induced aggrecan release. This in turn helps to slow down cartilage degradation and osteophyte formation.
=== Effects of drugs on propranolol === Propranolol is metabolized by cytochrome P450 enzymes including CYP2D6, CYP1A2, and CYP2C19. Levels of propranolol may be increased by CYP2D6 inhibitors such as amiodarone, bupropion, cimetidine, duloxetine, fluoxetine, paroxetine, propafenone, quinidine, and ritonavir, by CYP1A2 inhibitors such as imipramine, cimetidine, ciprofloxacin, fluvoxamine, isoniazid, theophylline, zileuton, zolmitriptan, and rizatriptan, and by CYP2C19 inhibitors such as fluconazole, cimetidine, fluoxetine, fluvoxamine, teniposide, and tolbutamide. No interactions with propranolol were observed with ranitidine, lansoprazole, or omeprazole. Propranolol levels may be reduced by inducers of hepatic metabolism including rifampin, alcohol, phenytoin, phenobarbital, and cigarette smoking. The CYP2D6 inhibitor quinidine has been found to increase propranolol levels by 2- to 3-fold. The CYP1A2 inhibitor fluvoxamine has been found to increase propranolol levels by 5-fold. The calcium channel blocker nisoldipine increased peak levels of propranolol by 1.5-fold and area-under-the-curve levels by 1.3-fold, while nicardipine increased propranolol peak levels by 1.8-fold and area-under-the-curve levels by 1.5-fold. Conversely, verapamil does not affect the pharmacokinetics of propranolol and vice-versa. The CYP1A2 inhibitor zolmitriptan increased peak propranolol levels by 1.4-fold and area-under-the-curve levels by 1.56-fold, while the CYP1A2 inhibitor rizatriptan increased propranolol peak levels by 1.8-fold and area-under-the-curve levels by 1.7-fold.
By April 2022, 12 IFPs have been completed by the administration, while 88 IFPs, which were on their "advanced stage", have been passed on to the succeeding administration for completion. From June 2016 to July 2021, a total of 29,264 kilometers (18,184 mi) of roads, 5,950 bridges, 11,340 flood control projects, 222 evacuation centers, and 150,149 elementary and secondary classrooms, and 653 COVID-19 facilities under the Build, Build, Build program had been completed.
Sources: en.wikipedia.org
In common usage, yes, but technically creatine monohydrate is one specific hydrated salt form. Other creatine forms exist and differ in composition and properties. The monohydrate is the most studied and most widely available grade.
Yes. Each creatine molecule in the crystal is associated with one water molecule. That water contributes to the total mass but is not part of the creatine molecule itself. Heating or drying can remove some or all of this water.
It occurs naturally in meat and fish, and the human body also makes and stores creatine. Food sources provide varying amounts depending on the type and preparation. The compound is not considered an essential dietary nutrient for adults because the body can synthesize it.
Purity is commonly assessed by HPLC, which separates creatine from related compounds such as creatinine. Water content is measured separately by Karl Fischer titration. Together these results help calculate the actual creatine content in a sample.