A hydraulic drive system for an actuator uses a pair of pressure compensated hydraulic machines to control flow to and from the drive chambers of the actuator by varying the controlled pressure of one of the machines. The organic medium can be a solvent, and the process can include causing the rapamycin analog to dissolve into the solvent, and incubating the solvent until the rapamycin analog crystallizes. A plurality of contact terminals is adapted to be disposed within the connector body, and extend from the front face for mating with the conductive elements. The end protector system of the present invention further includes a retention system to ensure that individual end protectors remain in place during transportation andor prolonged storage of such tubular goods. An auxiliary pump is provides to pump water into the axial gap and therefore create a hydrostatic pressure on the rotor to counteract the electromagnetic attraction forces generated during the operation of the device. Said geared motors are kinematically connected to two threaded rods by a toothed wheel and by threaded bushings which are also toothed on the outside.