Preparation and crystallization of aspirin

This is particularly true when a solid drug is delivered in tablets or capsules, but also relevant to other dosage forms such as suspensions and powders.

Preparation and crystallization of aspirin

By calculating the theoretical yield based on the original amount of Salicylic acid, one could determine the actual yield percentage of the reaction.


By measuring the melting point of the synthesized substance as well as taking a UV spectroscopy, it is then possible to measure the purity of the synthesized compound as well. With the yield percentage and the purity of the product, one Preparation and crystallization of aspirin get an accurate picture of the efficiency of this process.

Introduction Organic compounds are a certain type of compounds that contain carbon. The organic molecule actually synthesized in this experiment is Acetylsalicylic Acid, commonly known as Aspirin.

Acetylsalicylic Acid is derived from Salicylic acid, which then reacts with Acetyl Anhydride as per the following reaction in Figure 1. Reaction Reaction of Salicylic Acid and Acetic Anhydride to form Aspirin and Acetic Acid The rings shown in the Salicylic acid and Aspirin molecules are hexagonal rings of carbon compounds, with alternating single and double bonds as indicated by the double lines.

There are Hydrogen atoms bonded to some of the carbon molecules as well, but these are not shown for the sake of simplicity. The mechanism of the reaction is more complicated than this, however. Many intermediary steps happen in between the first and last steps, however. These can be seen in Figure 2, which shows the mechanism of the reaction in the presence of H3PO4, a catalyst: Mechanism of Reaction Many intermediate steps occur in the reaction Salicylates have a long history of use to alleviate aches and pain.

C Hippocrates documented that extract from the bark of the willow tree Salix genera could be used as a remedy for fever, pain, and inflammation, though evidence suggests that people knew about its effects long before. Testing showed that such extract would contain 1.

This is partially because of the fact that Salicylic acid is a diprotic acid; this means that when Salicylic acid dissolves in water, it releases two Hydronium ions and makes the solution more acidic than if the same number of a monoprotic acid molecules were added.

Preparation and crystallization of aspirin

A monoprotic acid is one that only releases one Hydronium ion when it dissolves in water. InFelix Hoffmann discovered that there was indeed a way to make this drug less irritating to the throat and stomach: With a name, Bayer proceeded to commercialize the Acetylsalicylic Acid inthough it was not until that Aspirin was released as an over-the-counter non-steroidal anti-inflammatory drug.

A few concepts are understood to be known in this experiment. The first of these is the concept of a limiting reactant. Whenever two or more reactants are brought together to do something, they react in particular whole-number ratios.

As such, any reactant that exists in an amount more than this whole number ratio is known as an excess reactant and some will be left over when the reaction is completely finished.


The reactant that is used up in its entirety is known as the limiting reactant. By using molar masses and these whole number molar ratios, it is also possible to calculate the theoretical yield of the reaction.Introduction to Qualitative and Quantitative Analysis - Principle of volumetric analysis -Separation techniques - extraction - distillation - crystallization - Chromatographic separations - Principles and application of column, .

外部発表論文リスト 外部発表履歴クエリ 安部 力 Abe, Chikara Abe, C., Tsuru, Y., Iwata, C., Ogihara, R. and Morita, H. Intravenous Infusion of Hyperosmotic NaCl Solution Induces Acute Cor Pulmonale in Anesthetized Rats.

The crystals are so dissolved in 5ml of ethyl alcohol. 30ml of hot, distilled H2O is added into the solution, and easy cooled.

Crystallization of Aspirin will take topographic point as the solution is cooled to room temperature. Suction filtration is done to take the Aspirin from the solution.

The Merck Index, which is an encyclopedia of chemicals, drugs and biologicals, lists the following information under aspirin: acetylsalicylic acid; monoclinic tablets or needle-like crystals; mp °C (rapid heating); is odorless, but in moist air it is gradually hydrolyzed into salicylic and acetic acids; one gram dissolves in mL of water at 25 °C, in mL of water at 37 °C, in 5 mL alcohol, in 17 mL chloroform.

Apr 27,  · Understanding The Section 3(D) Of The Patents Act, Is Essential To Appreciate The Patent Law.

Perspective The FDA Amendments Act of — Assessing Its Effects a Decade Later; Original Article Effect of Aspirin on Cardiovascular Events and Bleeding in the Healthy Elderly; Original.

Preparation and crystallization of aspirin
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