Abstract: A method of needleless medicant injection with an ampule having a medicant chamber and a bore extending therefrom dimensioned for needleless injection which includes the steps of evacuating the medicant chamber such that it is at less than ambient pressure, sealing the chamber from ambient pressure, thereafter exposing the chamber to a contained medicant to permit transfer of the medicant into the chamber, and then exposing the medicant in the chamber to a higher than ambient pressure to force it through the bore.

Abstract: A needleless hypodermic injector ampule includes a main body forming a chamber which is at less than ambient pressure, a cannula extending from one wall of the body, and a rigid discharge portion contiguous with the body and having a bore extending therethrough, which bore is in fluid communication with the chamber and terminates in an orfice which is dimensioned for needleless injection. A method of needleless medicant injection with an ampule having a medicant chamber and a bore extending therefrom dimensioned for needleless injection includes the steps of evacuating the medicant chamber such that it is at less than ambient pressure, sealing the chamber from ambient pressure, thereafter exposing the chamber to a contained medicant to permit transfer of the medicant into the chamber, and then exposing the medicant in the chamber to a higher than ambient pressure to force it through the bore.