Abstract: A process for manufacturing a glass tube, comprising at least one doped silica layer, wherein the layer is formed by forming a gel in situ, by the atomization of a hydrolyzing agent, onto a layer of a gelable liquid containing an alkoxy silane on a cylindrical mandrel rotated in a centrifuge, the gelable liquid and/or hydrolyzing agent containing a doping element, whereafter the resulting gel layer is subjected, after the withdrawal of the mandrel, to at least one thermal treatment to dry the gel and convert it into doped vitreous silica. The process can be applied to the production of preforms for the manufacture of optical fibers.