I understand Dr Bill Wilson simply specified Crisco (a brand) as a
   record of his procedure. It was not intended as a recommendation over
   other solid vegetable shortenings.
 
   In the tracheal mite treatment with vegetable oil process, I looked at
   the labels of various vegetable oils and shortenings. The Crisco label
   says that it "may" contain a variety of oils. I read in a discussion of
   human hyper-sensitivity to certain foods, that these brand names may be
   quite diferent products, depending on where they are produced (Crisco in
   western Canada may be canola oil, in the eastern states may be corn oil
   or soya oil).
 
   I have made and  seen extender patties made with a variety of vegetable
   oils and hydrogenated vegetable oils (solid shortening). The main usual
   limit of 'shelf life" with these oils (I would expect) would be
   rancidity, a factor which I doubt would affect their effectiveness as
   extnder patties. I have seen extender patties made with the used
   semi-solid oil used for deep frying: it didn't look as clean as new, but
   probably worked just as well to hold particles of antibiotic away from
   moisture (the function in an antibiotic extender patty).
 
   I would guess that an extender patty without antibiotic would have a
   shelf life of several years (as long as its physical properties look
   reasonable), while one with antibiotic would have a shelf life about the
   same as the expiry date of the antibiotic.
 
   The commercially produced extender patties perhaps have an expiry date,
   which should be regarded as much as the date on the dry antibiotic.
 
 
   Kerry Clark, Apiculture Specialist
   B.C. Ministry of Agriculture
   1201 103 Ave
   Dawson Creek B.C.
        V1G 4J2  CANADA          Tel (604) 784-2225     fax (604) 784-2299
   INTERNET [log in to unmask]