Creatinine raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-07-13. Anything still debated is marked as such rather than presented as settled.
Regulatory treatment of creatine monohydrate varies by country and intended use. In some jurisdictions it is sold as a dietary supplement, while in others it may be treated as a food ingredient or a pharmaceutical raw material. Pharmacopeial monographs, where available, define identification, assay limits, and impurity thresholds. Manufacturers often follow these monographs or internal specifications to ensure batch-to-batch consistency. Analytical method validation is important because different methods can yield different apparent purity values if sample preparation or detection conditions are not controlled.
Quality control for creatine monohydrate begins with identity confirmation and assay determination. Laboratories commonly use high-performance liquid chromatography with ultraviolet detection, often after derivatization or using a suitable column, to quantify creatine. Karl Fischer titration measures water content, which helps verify the monohydrate stoichiometry. Additional tests screen for heavy metals, residual solvents, and microbial contamination depending on the intended use. These tests establish composition and purity rather than biological effect.
Stability studies examine how creatine monohydrate changes under controlled temperature and humidity. The solid is generally stable when kept dry, but moisture can promote hydrolysis to creatinine, especially in solution or at elevated temperatures. Color, odor, and assay values are monitored over time to detect degradation. Because degradation pathways depend on storage conditions, shelf-life claims should specify the tested packaging, temperature, and humidity. Open questions remain about the long-term behavior of different crystal habits and particle sizes.
Analytical laboratories commonly identify creatine monohydrate by high-performance liquid chromatography with ultraviolet detection, often after dissolving the sample in water or dilute acid. Ion-exchange or reversed-phase columns separate creatine from creatinine and related guanidino compounds. Nitrogen content can be checked by Kjeldahl or combustion methods, while moisture is measured by Karl Fischer titration or loss on drying. These techniques give complementary views: chromatographic purity addresses related substances, whereas moisture and elemental data confirm hydrate stoichiometry. No single test defines quality by itself; a combination is used in specifications.
Storage recommendations generally emphasize a cool, dry place away from direct sunlight and strong oxidizers. Sealed containers limit humidity exchange, which helps prevent clumping and gradual conversion to creatinine. Long-term stability studies usually monitor appearance, moisture, and purity at intervals under defined temperature and humidity conditions. Accelerated tests at elevated temperature can reveal degradation pathways, but they do not perfectly predict room-temperature shelf life. Questions remain about how much creatinine formation is acceptable in different product categories and how packaging choices affect that rate over time.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | Creatine hydrate; N-carbamimidoyl-N-methylglycine monohydrate | Synonyms vary by naming convention |
| Typical assay method | HPLC-UV | Often paired with a reference standard |
| Water content method | Karl Fischer titration | Confirms monohydrate stoichiometry |
| Degradation product | Creatinine | Forms more readily in solution and with heat |
| Typical storage temperature | 15–25 °C | Keep dry and away from direct sunlight |
== Research == Besides treatment of ADHD, atomoxetine was under formal development by Eli Lilly and Company for the treatment of major depressive disorder, Alzheimer's disease, and Parkinson's disease. However, development for these indications was discontinued. The drug reached phase 3 clinical trials for treatment of Parkinson's disease prior to being discontinued. Though not approved for depression, atomoxetine has been studied and used off-label in the treatment of this condition, for instance as an adjunct to selective serotonin reuptake inhibitors (SSRIs) and to treat residual symptoms such as fatigue, but data are limited. It has also been studied and used to treat comorbid depression in people with ADHD. Atomoxetine has been studied in the treatment of social anxiety disorder, with mixed findings. The drug has been found to reduce anxiety symptoms in children and adolescents with ADHD and comorbid anxiety disorders. Atomoxetine may be used in those with ADHD and bipolar disorder although such use has not been well established. Some benefit has also been seen in people with ADHD and autism. As with other norepinephrine reuptake inhibitors it appears to reduce anxiety and depression symptoms, although research has focused mainly on specific patient groups such as those with concurrent ADHD or methamphetamine dependence. Atomoxetine has been studied and used in the treatment of orthostatic hypotension. It has been reported to be more effective than midodrine. The drug synergistically increased blood pressure in combination with pyridostigmine.
α-Methylserotonin (αMS), also known as α-methyl-5-hydroxytryptamine (α-methyl-5-HT) or as 5-hydroxy-α-methyltryptamine (5-HO-αMT), is a tryptamine derivative closely related to the neurotransmitter serotonin (5-HT). It acts as a non-selective serotonin receptor agonist and has been used extensively in scientific research to study the function of the serotonin system.
== Awards and honours == Dame Commander of the Order of the British Empire (DBE) for services to global diabetes, research, policy and care management (2026 Birthday Honours) Commander of the Order of the British Empire (CBE) for services to diabetes research (2016) Fellow of the Academy of Medical Sciences (2018) Outstanding Achievement in Clinical Diabetes Research Award, American Diabetes Association (2025)
Liquid chromatography (LC) is a separation technique in which the mobile phase is a liquid. It can be carried out either in a column or a plane. Present day liquid chromatography that generally utilizes very small packing particles and a relatively high pressure is referred to as high-performance liquid chromatography. In HPLC the sample is forced by a liquid at high pressure (the mobile phase) through a column that is packed with a stationary phase composed of irregularly or spherically shaped particles, a porous monolithic layer, or a porous membrane. Monoliths are "sponge-like chromatographic media" and are made up of an unending block of organic or inorganic parts. HPLC is historically divided into two different sub-classes based on the polarity of the mobile and stationary phases. Methods in which the stationary phase is more polar than the mobile phase (e.g., toluene as the mobile phase, silica as the stationary phase) are termed normal phase liquid chromatography (NPLC) and the opposite (e.g., water-methanol mixture as the mobile phase and C18 (octadecylsilyl) as the stationary phase) is termed reversed phase liquid chromatography (RPLC). A specialization of liquid chromatography is nano-liquid chromatography (nano-LC).
Sources: en.wikipedia.org
A tandem mass spectrometer is one capable of multiple rounds of mass spectrometry, usually separated by some form of molecule fragmentation. For example, one mass analyzer can isolate one peptide from many entering a mass spectrometer. A collision cell then stabilizes the peptide ions while they collide with a gas, causing them to fragment by collision-induced dissociation (CID). A further mass analyzer then sorts the fragments produced from the peptides. Tandem MS can also be done in a single mass analyzer over time, as in a quadrupole ion trap. There are various methods for fragmenting molecules for tandem MS, including collision-induced dissociation (CID), electron capture dissociation (ECD), electron transfer dissociation (ETD), infrared multiphoton dissociation (IRMPD), blackbody infrared radiative dissociation (BIRD), electron-detachment dissociation (EDD) and surface-induced dissociation (SID). An important application using tandem mass spectrometry is in protein identification. Tandem mass spectrometry enables a variety of experimental sequences. Many commercial mass spectrometers are designed to expedite the execution of such routine sequences as selected reaction monitoring, precursor ion scanning, product ion scanning, and neutral loss scanning.
=== Loans === In 2014, the museum conducted its first major loan of artifacts to another institution. Approximately 2,000 objects from its collection went on display at the John Heinz History Center in Pittsburgh, Pennsylvania, on May 31, 2014. Because the Arabia was built in Pittsburgh and Brownsville, Pennsylvania, in 1853, the temporary exhibition was called "Pittsburgh's Lost Steamboat: Treasures of the Arabia". In addition to the artifacts, Heinz curators displayed information about the preservation process and a replica of the mule that represents the only fatality of the sinking. This exhibition ran through January 4, 2015.
== Discovery of MiHAs == The significance of MiHAs in an immune response was recognized following transplantation. The recipient developed GVHD despite having a HLA- matched genes at the Major Histocompatibility locus. The experiment raised questions about the possibility of there being MiHAs. More specifically, the first MiHA was discovered when bone marrow transplantation occurred between opposite sexes. The female recipient obtained MHC-matched bone marrow cells but still had active cytotoxic T cells (CD8+). The CD8+ T cells were active and targeted the male bone marrow cells. The male bone marrow cells were found to be presenting a peptide in the MHC groove encoded by a gene on Y chromosome. The peptide was foreign to the female T cells and females lack the Y chromosome and, thus, this MiHA. The MiHAs encoded by the Y chromosome are known as HY antigens.
=== Immunology === Immunology is the branch of medicine that deals with the immune system, a network of biological systems that protects humans from diseases. The immune system detects and responds to pathogens, such as viruses, bacteria, and parasites, as well as cancer cells and foreign bodies. Humans have two major immune subsystems: The innate immune system, which provides a preconfigured response (e.g. defensins, complement system) to broad groups of situations and stimuli; and the adaptive immune system, which provides a tailored response to each stimulus by developing an immunological memory of molecules previously encountered. Mechanisms common to both subsystems, include phagocytosis, humoural immunity, cell-mediated immunity.
==== Reclaimed water as feedstock ==== As semiconductor fabrication has scaled, the volume of feedwater required for ultrapure water production has grown substantially, with advanced fabrication plants consuming several million gallons of UPW per day. To reduce reliance on freshwater withdrawals, some manufacturers have begun using reclaimed municipal or industrial wastewater as raw feedstock for UPW production. Reclaimed water typically contains higher levels of small-molecule organic pollutants such as urea, which are not effectively removed by conventional ion exchange, reverse osmosis, or ultraviolet treatment. As a result, advanced oxidation processes (AOPs), including UV-AOP and sulfate-radical–based methods, have been investigated as supplementary unit operations to meet the increasingly stringent total organic carbon specifications required for sub-7 nm device fabrication.
Sources: en.wikipedia.org
=== Box office === Dredd earned $27.6 million from markets outside of North America and $13.4 million from North America, for a total of $41 million. In the UK, Dredd grossed £1.05 million ($1.7 million) from 415 cinemas during its opening weekend. This made it the weekend's number-one film, the first film restricted to audiences over 18 years of age to do so since Saw 3D in 2010. In its second weekend, the film placed number five, earning £769,381. Dredd was primarily shown in 3D in the UK, and 2D screenings were notoriously limited as the distributor denied cinemas' requests for 2D prints; the decision was considered to have limited the film's audience where 2D was their preferred format. Dredd earned a total of $6.9 million in the UK. In North America, pre-release tracking estimated that the film would gross between $8 and $10 million during its opening weekend based on its adult rating and the poor reputation of the 1995 adaptation. The film earned $2.2 million on its opening day and finished the weekend in sixth place, grossing $6.3 million from 2,506 cinemas—an average of $2,514 per cinema. The largest demographic of the opening weekend audience was over the age of 25 (69%) and male (75%). The film's North American run ended on 1 November 2012, after 42 days. Outside of the UK and North America, Dredd had its most successful total gross takings in China ($4.5 million), Russia ($4 million), and Australia ($2 million). Urban criticised the film's marketing campaign, saying that the film had "zero audience awareness. Nobody knew the movie was being released.
Unique identifiers for types of examined properties of the patient, supporting structured communication and storage of laboratory data in e.g. clinical laboratory reports or electronic health records Stable and unambiguous definitions of the types of examined properties, expressed using international nomenclatures, and in accordance with international standards Specification of measurement units where relevant A structure allowing for secure translation of the definitions into other languages
It was first detected spectroscopically in late 1931 by Harold Urey, a chemist at Columbia University. Urey's collaborator, Ferdinand Brickwedde, distilled five liters of cryogenically produced liquid hydrogen to 1 mL of liquid, using the low-temperature physics laboratory that had recently been established at the National Bureau of Standards (now National Institute of Standards and Technology) in Washington, DC. The technique had previously been used to isolate heavy isotopes of neon. The cryogenic boiloff technique concentrated the fraction of the mass-2 isotope of hydrogen to a degree that made its spectroscopic identification unambiguous.
== Ownership == Ranpak was sold in December 2001 to First Atlantic Capital for over $100 million. In December 2005, First Atlantic sold Ranpak to American Capital Strategies Ltd., which in turn sold Ranpak Corp to Odyssey Investment Partners in 2007. Rhone Group acquired the company in 2014. In 2019, a group led by One Madison Group and its founder, Omar Asali, purchased Ranpak from Rhone Group for $950 million. Asali, former co-head of Goldman Sachs Hedge Fund Strategies, is the current president and CEO.
Sources: en.wikipedia.org
Karl Fischer titration is a standard method for measuring water content in solid and liquid samples. The result helps confirm the expected monohydrate stoichiometry. Loss-on-drying can also indicate moisture but may not distinguish water from other volatile substances.
Creatinine forms through irreversible cyclization and loss of water from creatine, and the rate increases with temperature, moisture, and pH changes. In dry solid form, the reaction is slow. In solution, degradation can become noticeable over time.
A specification typically lists assay range, water content, appearance, identification, and limits for heavy metals, residual solvents, and microbial counts. It may also include particle size distribution or bulk density for handling purposes. These parameters are distinct from any claimed performance effect.
Laboratories typically combine chromatographic separation with moisture and elemental analysis. High-performance liquid chromatography can quantify creatine and related substances such as creatinine. Moisture methods confirm the hydrate form and help detect excess water.