Wednesday, May 28, 2014

Oh, patents! Bupropion Hcl

Copyright © Françoise Herrmann 

Just three days till May 31The UN World No Smoking Day! And just enough time for your physician to perhaps decide on prescribing bupropion hydrochloride in sustained release (SR) form, commercially marketed as Zyban® by GalxoSmithKline as an effective aid to smoking cessation.

This pharmacotherapy for smoking cessation differs from nicotine and nicotine-replacement therapies in that it is an active ingredient  completely un-related to nicotine.  It is the third and most recent approach to smoking cessation. As a reminder the other combination lines of treatment are behavioral and nicotine-replacement-type therapies, such as transdermal patches, gum and lozenges.

The active ingredient bupropion hydrochloride was initially marketed in the United States as an antidepressant under the brand name Wellbutrin®, manufactured by GlaxoSmithKline. The structure of the active ingredient bupropion hcl is similar to diethylpropion, an appetite suppressant. Clinical testing of the drug demonstrated its effectiveness as a cessation drug as it doubles the success rate of the cessation, and is as effective as nicotine replacement therapies in conjunction with behavioral therapies (Roddy, 2004). It is unclear how bupropion hlc actually supports cessation although the effects of the drug on brain activity are known. It is hypothesized that inhibition of the reduction of dopamine and noradrelanine levels occurring with nicotine withdrawal is probably responsible. (Roddy, 2004).

Bupropion hlc is a highly patented compound. The search term “bupropion” returned 453 hits at the EPO!

The discovery of the compound is patented in US3819706 titled Meta chloro substituted alpha-butyl-amino propiophenone, as well as many of  its various formulations, for example US2011020446 titled Method and formulations for making pharmaceutical compositions containing bupropion.

  The various properties of the compound (including smoking cessation) are patented:
  • as an anti-depressant, for example, US2009304786 titled Stable dosage forms of an antidepressant
  • as appetite suppressant, for example, US2011144145 titled Methods of treating visceral fat conditions or US 2011098289 titled Method for treating obesity
  • as treatment for sexual dysfunction,  for example WO2012028834 titled Use of bupropion in the treatment of sexual dysfunction
  • as an aid to smoking cessation: for example US2003064092 titled Pharmaceutical composition containing two active ingredients for smoking cessation or US2004225020 titled Methods and compositions for aiding smoking cessation and for treating pain and other disorders using optically pure (-)-bupropion

 And the mode of delivery of the compound (in SR- Sustained release form) and its manufacture are patented, for example in US2010008987 titled Modified release pharmaceutical composition of bupropion hydrochloride, considering all the severe side effects that occur at peak plasma levels.

There are however warnings associated with the use of this therapy, as it is linked to neuropsychiatric reactions, suicidal thoughts and behaviors, particularly with younger populations. (GSK – Zyban)
So, with just a couple days left before the big Q day, Carpe Diem!

Roddy, E. (2004) Buproprion and other non-nicotine pharmacotherapies. BMJ Feb. 20, 2004, 328(7438):509-511.
GlaxoSmithKline – Zyban  - Highlights of prescribing information

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