whats so hard about making amorphous drugs?

why does one want them to be amorphous?

what are three top selling examples of amorphous drugs?

what are 3 situations where you want a drug to NOT be amorphous and
what are 3 top selling examples?

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Clarification of Question by baz229-ga on 28 Sep 2004 16:29 PDT

any advice as to why this isn't getting a response??

Hi baz229,
Here's what I found in answer to some of your questions.

whats so hard about making amorphous drugs?

[1]"For most substances, the amorphous form is unstable, returning to
more stable crystalline form in a few minutes or hours."


why does one want them to be amorphous?
[2]"The beauty of amorphous forms is that they have a higher
dissolution rate and solubility than crystalline forms. However, very
few drugs are naturally amorphous."

Unfortunately, the only top selling amorphous drugs I found are:
Accupril/Accuretic, which makes over $300 Million in revenues
Worldwide.[3] is used to treat High Blood Pressure.[4]

Intraconazole, an Acne medication seems to use amorphous substances
in order to improve bioavailability or absorption.[6]


what are 3 situations where you want a drug to NOT be amorphous and
what are 3 top selling examples?

I think one situation that best sums up when a drug should NOT be amorphous
is when it does not dissolve easily in water.

[5]"Improvement of solubility and oral bioavailability of a poorly
water-soluble drug, TAS-301, by its melt-adsorption on a porous
calcium silicate....The drug existed in an amorphous state in the
product and hardly recrystallized even after storing at a stressed
condition (60°C/80% RH for 3 days)."


[7]"Drugs that dissolve in fat (fat-soluble drugs), such as the
anesthetic drug halothane, tend to concentrate in fatty tissues"


Sources
========
[1]http://www.howe.k12.ok.us/~jimaskew/chem/csolid.htm

[2]http://healthsci.otago.ac.nz/division/news/research_topics/rades.html

[3]http://www.pfizer.com/download/news/2004Q2_earnfin4.pdf

[4]http://www.drugs.com/PDR/Accuretic_Tablets.html

[5]http://www.aapspharmaceutica.com/search/view.asp?ID=4925 

[6]http://www.pharmcast.com/Patents/Yr2002/Feb2002/021202/6346533_itraconazole021202.htm

[7]http://www.merck.com/mmhe/sec02/ch011/ch011d.html


Please let me know if you have anymore questions.
Thank you.

-googleexpert

Search Strategy
==================
amorphous (pfizer, glaxosmithkline..... and other pharmaceutical companies)

might be 4 but i haven't had time to thoroughly review or respond