Navigation Links
Does Aspirin Crystallize?

When people get headache, they probably reach for aspirin. What is giving researchers a headache is the question of the crystal structure of aspirin, doubting// whether there is another form on top of the long-known one! - A team of scientists from Denmark, Germany, and India seems to have solved this controversial puzzle: yes, there is a second structure—but it does not exist as a pure form.

“The two crystalline forms of aspirin are so closely related,” explains the research team of Andrew D. Bond, Roland Boese and Gautam R. Desiraju in Angewandte Chemie, “that they form structures containing domains of both crystal types.”

In 2004, computer calculations had indicated that while the long-known crystal structure of aspirin (form I) is definitely one of the most stable forms, another version might exist that is just as stable, though it had not yet been discovered—a clear challenge to researchers in the field. The difference between the proposed structures is slight: both have identical layers containing molecules grouped into pairs, but these layers are arranged differently in the two different structures.

In 2005, researchers in the USA announced the discovery of the predicted structure (form II). But was this merely an artifact?

“We can now clear this matter up,” say Bond, Boese and Desiraju, after very careful examination of aspirin crystals. “Aspirin has a tendency to crystallize with an unusual intergrown structure. The same single crystal contains domains with both arrangements lying side by side.” The distribution and ratio of the domains are variable but limited. Whereas a pure form I exists, it has so far only been possible to obtain crystals containing a maximum of 85 % form II. The ratio of the two domains within crystals produced under identical conditions seems to be roughly constant.

This discovery upends fundamental principles and requires new concepts: chemists previously understood “polymorphism” to mean that a molecule can take on one or another packing arrangement in the crystalline state; a single crystal of a specific chemical substance is either one polymorph or the other.

Aspirin is the first case in which two different “polymorphic” structures exist in one single crystal. So is aspirin polymorphic or not? Should the definition of polymorphism be updated? Such questions are not just philosophical in nature, but could have tangible implications in patent law, because each polymorph of a compound is viewed as a separate patentable substance.

Source-Eurealert
SRI
'"/>




Related medicine news :

1. What happens when Asthmatics consume Aspirin?
2. Aspirin reduces deaths
3. Aspirin and Warfarin Are Equally Effective for Stroke Prevention
4. Aspirin - a drug after one’s own hear
5. Aspirin deflated
6. Aspirin surpasses Modern Anti-clotting Drugs
7. Night Time Aspirin Regimen Found to Reduce Blood Pressure
8. Aspirin Lowers Leukemia Risk
9. Aspirin usage linked with pancreatic cancer
10. Aspirin Found To Reduce The Risk Of Colon Cancer
11. Aspirin Induced Asthma , A Little-Known Inducer
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:2/5/2016)... ... February 05, 2016 , ... Love is in the air at King ... colors, assortments and packaging. This staple for Valentine’s Day is a must-have, and can ... For Valentine’s Day, not only are long-stem roses available, but also other flower bouquets, ...
(Date:2/5/2016)... ... February 05, 2016 , ... ... stage for new clinical and scientific initiatives have all marked the last 12 ... appointed President and CEO of the nation’s oldest cancer center, Candace S. Johnson, ...
(Date:2/5/2016)... ... February 05, 2016 , ... Francisco ... micro-needling services in their Napa Valley office. The technique utilizes the body’s own ... Dr. Canales and Dr. Furnas, are part of only a select few cosmetic ...
(Date:2/5/2016)... ... ... After years as an active staff surgeon and having served as the director ... transitioned to chief of the Division of Plastic Surgery at what is now known ... began a second three-year term in January of 2016. , The original selection was ...
(Date:2/5/2016)... ... February 05, 2016 , ... In the fourth quarter ... gathered at the La Valencia Hotel in San Diego, California to discuss changes ... the year’s most outstanding franchise, walking away with the coveted David Wright Award ...
Breaking Medicine News(10 mins):
(Date:2/5/2016)... India , February 5, 2016 ... a new market research report "Fetal (Labor & Delivery) ... & Antepartum), Warmer, Incubator, Pulse Oximeter, Phototherapy/Jaundice Management Devices, ... published by MarketsandMarkets, This report studies the global market ... market is estimated at USD 6.28 Billion in 2015 ...
(Date:2/4/2016)... 2016 For hospitals considering enrollment in the ... in the program, the Health Resources and Services Administration,s ... , Mega-Guidance , could have significant impact on plans ... September 2016. Essential Insights , Daniel ... summarizes the Mega-Guidance,s key proposed changes, including a new ...
(Date:2/4/2016)... , Feb. 4, 2016  SciClone Pharmaceuticals, ... announced it has entered into a settlement agreement ... (SEC) fully resolving the SEC,s investigation into possible ... Under the terms of the settlement agreement, SciClone ... million, including disgorgement, pre-judgment interest and a penalty.  ...
Breaking Medicine Technology: