E-DRUG: Norgestrel and combined contraceptive pills (cont'd)

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E-drug: Norgestrel and combined contraceptive pills (cont'd)
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Dear Marcel,

Only concerning the last bit of your question:

Is there perhaps a -huge- price difference between the d-norgestrel
only pill and the mixed norgestrel containing pill?

Drawing on my pharm. chemistry from some years ago:
optically pure substances (single enantiomers) can be obtained

   a) either by stereo-specific synthesis => difficult, low performance,
      costly

      or

   b) by synthesis of the racemic mixture with subsequent split-up,
      done either by

      converting it to a diastereomeric substance with some cheap
      product, differential cristallisation (d/l, as diastereoisomers have
      different physical properties), then re-convert the fraction of
      interest back to original substance (somewhat tedious)

      or

      selective retention in HPLC chromatography with an optically
      active stationary phase (expensive, large scale required)

All of the above is only done when one of the enantiomers has either
non-acceptable side effects, or a different pharmacological property
which makes it a drug in its own right (see quinine / quinidine)

In how far the l- enantiomer is harmful... can't tell you right now,
sorry.

Hope this helped a bit, nonetheless.

Cheers,

York Francis Zoellner, lic. pharm.
Dept. Economics and Related Studies
University of York, Alcuin College
Heslington, Y o r k YO1 5DD
UK
Fax: **44 - 1904 - 43. 37 59
Tel. **44 - 1904 - 43. 37 90 (to leave a message)
e-mail: yfz100@york.ac.uk
Web: http://www.york.ac.uk/~yfz100

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