A practical reference on lyophilisation: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-06-24 and is reviewed periodically as new material appears.
纯度评估通常综合反相色谱、体积排阻色谱与质谱三方面信息：前者反映疏水性杂质，后者反映聚集体，质谱则确认分子量与主要降解产物。有关降解途径的完整图谱——例如脱酰胺、氧化与水解各占多大比例——在不同储存条件下仍有差异，属于需要逐案验证的问题。
质量控制环节关注外观、含量、纯度、有关物质、水分与微生物限度等项目。检测结果需要有对照品和系统适用性数据支持，单次测定不足以判定批次的稳定性。实验室之间方法转移时，色谱柱品牌与梯度差异常导致保留时间漂移，因此方法验证十分必要。
固体状态的 tirzepatide 通常以冻干粉形式保存，推荐在低温、避光、干燥条件下存放，常见区间为 2 至 8 摄氏度，长期保存可考虑更低温度并避免反复冻融。冻融循环会导致肽链聚集或析出，从而影响后续定量结果。容器密封性与湿度控制同样是稳定性研究中反复强调的因素。
Development began in the 2010s, when researchers modified a GIP-based scaffold to add GLP-1 activity and then attached the fatty diacid to lengthen its half-life. Clinical evaluation proceeded through large phase 3 programmes in type 2 diabetes and in obesity, and regulators in the United States cleared the compound for type 2 diabetes in 2022 and for chronic weight management in 2023. Several cardiovascular and metabolic outcome studies are still reporting, so the picture of long-term benefit and risk is incomplete. Approvals in other regions followed on different timelines.
Tirzepatide is a synthetic peptide of 39 amino acids that carries a C20 fatty diacid side chain attached through a linker. Its molecular formula is C225H348N48O68, and its molecular weight is about 4813 daltons. The compound belongs to the incretin mimetic class and is administered by subcutaneous injection. The fatty acid chain promotes binding to serum albumin, which slows renal clearance and extends the circulation time of the molecule. It was identified during screening of sequences derived from glucose-dependent insulinotropic polypeptide.
| Property | Value | Notes |
|---|---|---|
| 储存温度 | 2 至 8 摄氏度 | 固体粉末，避光密封 |
| 外观 | 白色至类白色冻干粉 | 溶解后为澄清至微乳光 |
| 溶解性 | 易溶于水性缓冲液 | 避免剧烈振荡 |
| 常规纯度方法 | 反相高效液相色谱 | 紫外或质谱检测 |
| 定量方法 | 液相色谱串联质谱 | 配合固相萃取前处理 |
Clinical research programs have evaluated tirzepatide in adults with type 2 diabetes and in adults with obesity or excess weight. Trials generally reported reductions in glycated hemoglobin and body weight across treatment periods of several months. Since these studies enrolled defined populations under controlled conditions, the findings describe group averages rather than individual outcomes. Open questions include the durability of effects after treatment stops, variation among subgroups, and the long-term consequences of sustained dual receptor stimulation. Published trial summaries should be consulted for exact measurements rather than secondary accounts.
Tirzepatide is a synthetic peptide built from 39 amino acid residues. Its backbone derives from the native glucose-dependent insulinotropic polypeptide sequence, altered at several positions to resist enzymatic cleavage. A fatty diacid group attached through a linker extends plasma residence time by promoting reversible binding to serum albumin. The molecule carries a net negative charge near physiological pH and has a reported molecular weight close to 4813 daltons. These features separate it from shorter incretin analogs and account for its prolonged dosing interval.
Recommended storage for reference material is a freezer at approximately -20 degrees Celsius, protected from light and moisture. Commercial injectable presentations are stored refrigerated between 2 and 8 degrees Celsius and must not be frozen. Product labelling generally permits a limited period at controlled room temperature once dispensed, with the exact window depending on the presentation. Repeated temperature cycling is avoided because it can promote aggregation or deamidation of the peptide chain.
Identity and purity are assessed by reversed-phase high-performance liquid chromatography, with mass confirmation by electrospray ionisation mass spectrometry. Peptide mapping after enzymatic digestion verifies the primary sequence. Size-exclusion chromatography quantifies aggregates, while circular dichroism provides a secondary-structure fingerprint. Bioanalytical quantification in plasma uses immunoassay or LC-MS/MS. Reported purity for research-grade lots is commonly 95 percent or higher, and residual water content is checked by Karl Fischer titration.
As a peptide, tirzepatide is handled as a lyophilised solid in research settings and as a preserved solution in finished products. Aqueous solubility is pH dependent and reaches a minimum near the isoelectric point, which lies close to pH 5.4. Stock solutions are typically prepared in neutral or slightly basic buffer to limit precipitation. The solid is hygroscopic and should be equilibrated to room temperature before opening so that condensation does not form on the powder surface.
The molecule is a synthetic 39-amino-acid peptide whose backbone derives from the sequence of human glucose-dependent insulinotropic polypeptide, with several substitutions that raise metabolic stability and shift receptor preference. A C20 fatty diacid is attached through a short linker to a lysine side chain, a modification that increases binding to serum albumin. The reported monoisotopic mass is approximately 4813 Da. Near neutral pH the peptide carries a net negative charge, and the lipid tail makes the molecule markedly more hydrophobic than the unmodified parent sequence.
Dual agonism at the GIP and GLP-1 receptors underlies the observed pharmacology. Activation of GLP-1 receptors raises glucose-dependent insulin release, lowers glucagon secretion, slows gastric emptying and reduces appetite. GIP receptor activation contributes additional effects on adipose tissue and on energy balance, and the combined action on appetite appears larger than either pathway alone in animal models. Signalling bias and the relative contribution of each receptor arm to weight-related effects remain areas of active investigation.
在生理层面，GIP 与 GLP-1 均为肠道内分泌细胞分泌的肠促胰素，进食后参与胰岛素分泌调节与胃排空抑制。Tirzepatide 通过同时激活这两条信号通路，使胰岛素分泌的葡萄糖依赖性增强，并延缓冲胃排空、降低食欲信号。与单一 GLP-1 激动相比，双靶点作用在血糖控制和体重变化上的效应幅度更大，但具体贡献比例仍在研究之中。
脂肪酸侧链的存在使该肽与血浆白蛋白结合能力增强，从而延长循环半衰期，支持每周一次给药的用药间隔。白蛋白结合同时改变组织分布特征，减慢肾脏清除速度。该设计思路在多种长效肽类药物中被反复采用，属于既定的药代动力学策略。
该化合物的名称与结构由国际非专利名称体系统一维持，不同文献中出现的同义写法主要在拼写顺序或盐形式描述上不同。研究者通常通过受体结合实验、细胞内环磷酸腺苷积累测定以及动物模型来确认其双激动活性。相当一部分分子层面的细节——例如两条受体通路之间的信号交叉作用——尚处于开放问题状态。
In 2013, Chinese authorities announced that, since 2007, GSK had funnelled HK$3.8 billion in kickbacks to GSK managers, doctors, hospitals and others who prescribed their drugs, using over 700 travel agencies and consulting firms. Chinese authorities arrested four GSK executives as part of a four-month investigation into claims that doctors were bribed with cash and sexual favours. In 2014, a Chinese court found the company guilty of bribery and imposed a fine of US$490 million. Mark Reilly, the British head of GSK's Chinese operations, received a three-year suspended prison sentence after a one-day trial held in secret. Reilly was reportedly deported from China and dismissed by the company.
Since the exciton samples many potential analyte binding sites during its excited state lifetime, the probability that the exciton will sample an occupied ‘receptor’ site and be quenched is greatly increased."
Migalastat is used in form of the hydrochloride, which is a white crystalline solid and is soluble in water. The molecule has four asymmetric carbon atoms with the same stereochemistry as the sugar D-galactose, but is missing the first hydroxyl group. It has a nitrogen atom in the ring instead of an oxygen, which makes it an iminosugar.
Historically, CAIS has been referred to in the literature under a number of other names, including testicular feminization [syndrome] (deprecated) and Morris syndrome. PAIS has also been referred to as Reifenstein syndrome, which should not be confused with CAIS.
==== Monosaccharide reduction ==== There are many ways silver nanoparticles can be synthesized; one method is through monosaccharides. This includes glucose, fructose, maltose, maltodextrin, etc., but not sucrose. It is also a simple method to reduce silver ions back to silver nanoparticles as it usually involves a one-step process. There have been methods that indicated that these reducing sugars are essential to the formation of silver nanoparticles. Many studies indicated that this method of green synthesis, specifically using Cacumen platycladi extract, enabled the reduction of silver. Additionally, the size of the nanoparticle could be controlled depending on the concentration of the extract. The studies indicate that the higher concentrations correlated to an increased number of nanoparticles. Smaller nanoparticles were formed at high pH levels due to the concentration of the monosaccharides. Another method of silver nanoparticle synthesis includes the use of reducing sugars with alkali starch and silver nitrate. The reducing sugars have free aldehyde and ketone groups, which enable them to be oxidized into gluconate. The monosaccharide must have a free ketone group because in order to act as a reducing agent it first undergoes tautomerization. In addition, if the aldehydes are bound, it will be stuck in cyclic form and cannot act as a reducing agent. For example, glucose has an aldehyde functional group that is able to reduce silver cations to silver atoms and is then oxidized to gluconic acid. The reaction for the sugars to be oxidized occurs in aqueous solutions.
Sources: en.wikipedia.org
Charles III hands over the role of commander-in-chief of the Army Air Corps to Prince William after 32 years in the role. Changes to the welfare system require people on Universal Credit to work 18 hours a week, with those on less than 16 hours a week required to look for more work. 14 May – Manchester's Co-op Live venue finally opens after being beset by problems that delayed its launch. 15 May The UK Health Security Agency advises residents of south Devon to boil their tap water following 22 cases of infection caused by the parasite cryptosporidium. English Premier League football clubs are to vote on whether to scrap video assisted refereeing (VAR) at their annual general meeting in June. 16 May At a campaign event in Essex, Labour leader Keir Starmer outlines the first steps his party will take if they win the next general election. These are: economic stability, a cut in NHS waiting times in England, a new Border Security Command, the establishment of Great British Energy, a crackdown on antisocial behaviour in England, and 6,500 more teachers in England. The BBC reports that HPV vaccinations in young people are now so successful that cervical cancer "could be eradicated in the near future." South West Water says it believes a faulty valve may have allowed a parasite to enter the water network. 17 May Moroccan asylum seeker Ahmed Alid is sentenced to life imprisonment, with a minimum term of 45 years, for the murder of 70-year-old Terence Carney in Hartlepool.
=== Birds and reptiles === The epidermis of birds and reptiles is closer to that of mammals, with a layer of dead keratin-filled cells at the surface, to help reduce water loss. A similar pattern is also seen in some of the more terrestrial amphibians such as toads. In these animals, there is no clear differentiation of the epidermis into distinct layers initially, as occurs in humans, with the change in cell type being relatively gradual. The mammalian epidermis always possesses at least a stratum germinativum and stratum corneum, but the other intermediate layers found in humans are not always distinguishable. Hair is a distinctive feature of mammalian skin, while feathers are (at least among living species) similarly unique to birds. Birds and reptiles have relatively few skin glands, although there may be a few structures for specific purposes, such as pheromone-secreting cells in some reptiles, or the uropygial gland of most birds.
== History == Creatine was first identified in 1832 when Michel Eugène Chevreul isolated the precipitate from the basified water-extract of skeletal muscle. He later named the crystallized precipitate after the Greek word for meat, κρέας (kreas). In 1928, creatine was shown to exist in equilibrium with creatinine. Studies in the 1920s showed that consumption of large amounts of creatine did not result in its excretion. This result pointed to the ability of the body to store creatine, which in turn suggested its use as a dietary supplement. In 1912, Harvard University researchers Otto Folin and Willey Glover Denis found evidence that ingesting creatine can dramatically boost the creatine content of the muscle. The discovery of phosphocreatine was reported in 1927. In the 1960s, the enzyme creatine kinase was shown to phosphorylate ADP using phosphocreatine to generate ATP and thus buffering the ATP/ADP ratio. While creatine's influence on physical performance has been well documented since the early twentieth century, it came into public view following the 1992 Olympics in Barcelona. An 7 August 1992 article in The Times reported that Linford Christie, the gold medal winner at 100 metres, had used creatine before the Olympics. An article in Bodybuilding Monthly named Sally Gunnell, who was the gold medalist in the 400-metre hurdles, as another creatine user. In addition, The Times also noted that 110 metre hurdler Colin Jackson began taking creatine before the Olympics.
During this meeting, he asked what Weizmann's objections had been to the 1903 Uganda Scheme that Herzl had supported to provide a portion of British East Africa to the Jewish people as a homeland. The scheme, which had been proposed to Herzl by Joseph Chamberlain, Colonial Secretary in Balfour's Cabinet, following his trip to East Africa earlier in the year, had been subsequently voted down following Herzl's death by the Seventh Zionist Congress in 1905 after two years of heated debate in the Zionist Organization. Weizmann responded that he believed the English are to London as the Jews are to Jerusalem. In January 1914, Weizmann first met Baron Edmond de Rothschild, a member of the French branch of the Rothschild family and a leading proponent of the Zionist movement, in relation to a project to build a Hebrew university in Jerusalem. The Baron was not part of the World Zionist Organization, but had funded the Jewish agricultural colonies of the First Aliyah and transferred them to the Jewish Colonization Association in 1899. This connection was to bear fruit later that year when the Baron's son, James de Rothschild, requested a meeting with Weizmann on 25 November 1914, to enlist him in influencing those deemed to be receptive within the British government to the Zionist agenda in Palestine. Through James's wife Dorothy, Weizmann was to meet Rózsika Rothschild, who introduced him to the English branch of the family – in particular her husband Charles and his older brother Walter, a zoologist and former Member of Parliament (MP).
Like the genus Lactarius, russulas have a distinctive flesh consistency, which is also reflected in the appearance of the gills and stipe, and normally makes them immediately recognizable. They have no trace of a veil (no ring, or veil remnants on the cap). The gills are brittle except in a few cases, and cannot be bent parallel with the cap without breaking. Hence the genus Russula is sometimes known colloquially as "brittle gills". They have splitting gills and do not exude a milky substance at cut surfaces, contrary to the genus Lactarius. Presence of large spherical cells, 'sphaerocysts', in the stipe is an important characteristic feature to distinguish the members of Russulaceae from other mushrooms. In Russula, the stipe breaks like the flesh of an apple, while in most other families it only breaks into fibres. The spore powder varies from white to cream, or even orange. While it is relatively easy to identify a sample mushroom as belonging to this genus, it is a significant challenge to distinguish member species of Russula. This task often requires microscopic characteristics, and subtle subjective distinctions, such as the difference between a mild to bitter and a mild to acrid flavor. Moreover, the exact phylogenetic relationships of these mushrooms have yet to be resolved in the professional mycological community, and may ultimately depend on DNA sequencing analysis. The following characteristics are often important in identifying individual species:
Sources: en.wikipedia.org
=== Background === Until after the Second World War the landlocked British possession of Southern Rhodesia was not developed as an indigenous African territory, but rather as a unique state that reflected its multiracial character. This situation made it different from other lands that existed under colonial rule, as many Europeans had arrived to make permanent homes, populating the towns as traders or settling to farm the most productive soils. In 1922, faced with the decision to join the Union of South Africa as a fifth province or accept nearly full internal autonomy, the electorate cast its vote against South African integration. In view of the outcome of the referendum, the territory was annexed by the United Kingdom on 12 September 1923. Shortly after annexation, on 1 October 1923, the first constitution for the new Colony of Southern Rhodesia came into force. Under this constitution, Southern Rhodesia was given the right to elect its own thirty-member legislature, premier, and cabinet—although the British government retained a formal veto over measures affecting natives and dominated foreign policy. Over the course of the next three decades, Southern Rhodesia experienced a degree of economic expansion and industrialisation almost unrivalled in sub-Saharan Africa. Its natural abundance of mineral wealth—including large deposits of chromium and manganese—contributed to the high rate of conventional economic growth.
The lesions occur as multiple cutaneous and subcutaneous nodules up to 4 cm diameter. They may disappear spontaneously, or regress and appear at new sites simultaneously. Topographically lesions may be found on the face, ears, nose, neck, trunk, extremities (including foot pads), perineum and scrotum. Treatment options in SH and CH. SH has proven to be a difficult and frustrating condition to treat. Consequently, many of the early cases were euthanized. Originally we treated dogs with Thymosin (derived from bovine thymus) because of reports of its effectiveness in human LCH cases. Some dogs appeared to respond to this, but not consistently. The original rationale for using thymosin was that SH was likely an immunoregulatory disorder and not cancer. In the majority of instances corticosteroid treatment is ineffective, although in some instances of CH (about 10% of cases), steroid administration is very effective in controlling lesions so steroids are worth trying in this disease given the expense of the alternatives. More recently we have had success with immuno-suppressive doses of Cyclosporin A or Leflunomide. These drugs are potent inhibitors of T cell activation and their ability to abrogate clinical disease gives further support for SH and CH being disorders of immune regulation. Treatment with these drugs is exorbitantly expensive and may be needed for life in dogs with continuously active disease, which usually is the case in advanced SH.
=== SARMs === Selective androgen receptor modulators (SARMs) are a novel class of androgen receptor ligands. They are intended to maintain the desirable muscle building effects of anabolic steroids while reducing undesirable androgenic actions (e.g., increased risk of prostate cancer). SARMs that are more selective in their action could potentially be used for a broader range of clinical indications other than the relatively limited legitimate uses that anabolic steroids are currently approved for.
The Trade Development Authority of Pakistan (TDAP) was established in 2006. TDAP is the successor organization to the Export Promotion Bureau (EPB) and is mandated to have a holistic view of global trade development rather than only the ‘export promotion’ perspective of its predecessor. It is designated as the premier trade organization of the country.
Sources: en.wikipedia.org
建议在低温、避光、干燥环境中密封保存，常见条件为 2 至 8 摄氏度，长期存放可置于更低温度。应避免反复冻融，并尽量减少容器开启次数。
溶解后的稳定时间通常短于固体形态，受浓度、缓冲液和容器材质影响。冷藏条件下一般只能维持较短时间，具体期限应通过实际稳定性实验确认。
反相高效液相色谱用于纯度与含量测定，液相色谱串联质谱用于生物基质中的定量，体积排阻色谱用于检测聚集体。多种方法结合才能较完整地表征样品。
It is a synthetic 39-amino-acid peptide that acts on two incretin receptors, the GIP receptor and the GLP-1 receptor. It is given by subcutaneous injection and has a circulating half-life of roughly five days. It is not a small molecule and is not absorbed usefully from the gut in conventional oral form.