An iontophoretic patch for transdermal delivery of biologically active agents, comprising: a printed circuit board, at least two electrodes connected through electric contacts to said printed circuit board, at least two hydrogel reservoirs configured to, in use of the iontophoretic patch, be disposed on a user's skin, wherein at least one of said hydrogel reservoirs comprises at least one active agent carried therein to be delivered into the user's skin, wherein said at least two electrodes are in contact with respective at least two hydrogel reservoirs, at least one optical sensing system (3, 12) disposed in at least one of said hydrogel reservoirs for, in use of the iontophoretic patch, continuously measuring an amount of said at least one active agent in said at least one hydrogel reservoir, a control unit embedded on the printed circuit board, the control unit being configured to generate a stimulation pattern comprising a plurality of stimulation parameters to be delivered to a plurality of stimuli locations on the skin, wherein said at least two electrodes are configured to be activated or deactivated following said stimulation pattern, a stimulation unit embedded on the printed circuit board, the stimulation unit being configured to generate a time sequence of pulses from said plurality of stimulation parameters generated by the control unit, a demultiplexing unit embedded on the printed circuit board, the demultiplexing unit being configured to, from the time sequence of pulses generated by said stimulation unit and from said stimuli locations generated by said control unit, perform independent spatio-temporal distribution of the electrical pulses comprised in said time sequence of pulses to at least one electrode of said at least two electrodes, wherein each of said at least two electrodes are connected through respective electric contacts to said demultiplexing unit, each electric contact being activated independently through the demultiplexing unit, a feedback unit embedded on the printed circuit board, the feedback unit being configured to estimate, from said amount of at least one active agent measured at said at least one optical sensing system (3, 12), a temporal delivery profile of said at least one active agent into the skin, said control unit being further configured to compare an estimated delivery profile provided by the feedback unit with a desired delivery profile and to continuously modify said generated stimulation pattern by changing at least one of said plurality of stimulation parameters to be provided to the stimulation unit and/or said stimuli locations to be provided to said demultiplexing unit. a printed circuit board, at least two electrodes connected through electric contacts to said printed circuit board, at least two hydrogel reservoirs configured to, in use of the iontophoretic patch, be disposed on a user's skin, wherein at least one of said hydrogel reservoirs comprises at least one active agent carried therein to be delivered into the user's skin, wherein said at least two electrodes are in contact with respective at least two hydrogel reservoirs, at least one optical sensing system (3, 12) disposed in at least one of said hydrogel reservoirs for, in use of the iontophoretic patch, continuously measuring an amount of said at least one active agent in said at least one hydrogel reservoir, a control unit embedded on the printed circuit board, the control unit being configured to generate a stimulation pattern comprising a plurality of stimulation parameters to be delivered to a plurality of stimuli locations on the skin, wherein said at least two electrodes are configured to be activated or deactivated following said stimulation pattern, a stimulation unit embedded on the printed circuit board, the stimulation unit being configured to generate a time sequence of pulses from said plurality of stimulation parameters generated by the control unit, a demultiplexing unit embedded on the printed circuit board, the demultiplexing unit being configured to, from the time sequence of pulses generated by said stimulation unit and from said stimuli locations generated by said control unit, perform independent spatio-temporal distribution of the electrical pulses comprised in said time sequence of pulses to at least one electrode of said at least two electrodes, wherein each of said at least two electrodes are connected through respective electric contacts to said demultiplexing unit, each electric contact being activated independently through the demultiplexing unit, a feedback unit embedded on the printed circuit board, the feedback unit being configured to estimate, from said amount of at least one active agent measured at said at least one optical sensing system (3, 12), a temporal delivery profile of said at least one active agent into the skin, said control unit being further configured to compare an estimated delivery profile provided by the feedback unit with a desired delivery profile and to continuously modify said generated stimulation pattern by changing at least one of said plurality of stimulation parameters to be provided to the stimulation unit and/or said stimuli locations to be provided to said demultiplexing unit.