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:6/25/2016)... ... ... On Friday, June 10, Van Mitchell, Secretary of the Maryland Department of Health ... of their exemplary accomplishments in worksite health promotion. , The Wellness at Work Awards ... at the BWI Marriott in Linthicum Heights. iHire was one of 42 businesses to ...
(Date:6/24/2016)... Michigan (PRWEB) , ... June 24, 2016 , ... June ... about the dangers associated with chronic pain and the benefits of holistic treatments, ... individuals who are suffering with Sickle Cell Disease. , Sickle Cell Disease (SCD) is ...
(Date:6/24/2016)... San Francisco, CA (PRWEB) , ... June 24, ... ... at CitiDent, is now offering micro-osteoperforation for accelerated orthodontic treatment. Dr. Cheng has ... , self-ligating Damon brackets , AcceleDent, and accelerated osteogenic orthodontics. , ...
(Date:6/24/2016)... ... June 24, 2016 , ... EB ... Decision Making in Emergency Medicine conference in Ponte Vedra Beach, FL. The awards ... in Emergency Medicine Practice and Pediatric Emergency Medicine Practice. , “With ...
(Date:6/24/2016)... ... June 24, 2016 , ... National recruitment firm Slone Partners ... extensive sequencing and genomics experience, as Vice President of North American Capital Sales at ... responsible for leading the sales team in the commercialization of the HTG EdgeSeq system ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... 2016 Research and Markets has announced ... report to their offering. ... a favourable commercial environment for MedImmune to enter. The US ... will serve to drive considerable growth for effective anti-influenza medications. ... cap sales considerably, but development is still in its infancy. ...
(Date:6/23/2016)... and INDIANAPOLIS , June 23, ... a Lilly Diabetes Tomorrow,s Leaders Scholarship is any indication, ... winners, announced today online at www.diabetesscholars.org by ... 1 diabetes stand in the way of academic and ... the Foundation,s scholarship program since 2012, and continues to ...
(Date:6/23/2016)...  Guerbet announced today that it has been named ... . One of 12 suppliers to receive ... support of Premier members through exceptional local customer service ... to lower costs. ... outstanding customer service from Premier," says Massimo Carrara ...
Breaking Medicine Technology: