A carpule and its method of manufacture, the carpule tubular body composed of a polypropylene or similar polymer, the tubular body being sealed at one end by a seal of a thermoplastic vulcanizate (TPV) or similar polymer, the seal having been injection molded in contact with the tubular body prior to full curing of the material composing the tubular body, such that a chemical fusion bond is created between the seal and the tubular body.