Pfizer, manufacturers of Viagra, have lauched a variation of the product in the Mexican market.  The new product, Viagra Jet, is a chewable version which Pfizer think will be particularly suitable in the Mexican market.  Research has shown that  Mexican men find it difficult to swallow the current tablet and also crush the tablet in the belief that it will work faster.  This attempt to keep interest in the product follows the Bayer launch of an orodispersible, melt in the mouth, version of their Levitra tablet which they are marketing in nine European countries including the UK.  It is already attracting interest and sales from men who want a discreet, fast acting product.  This activity is designed to keep interest in the mainstream products in advance of the expected rise in generic versions of Viagra following the expiry of the chemical patent on 27th March 2012.  A use patent might prevent copies until 2019, but there is some doubt about this.  Cialis has already started the development ball rolling with their one-a day version which is also proving popular and growing their market share.  It looks as though all this activity will benefit the end user most.  Good news for all if this proves to be the case.