Blakes 7 Wiki
Helot hit with medical laser

Pylene-50 being delivered via medical laser (D: Traitor)

Pylene-50 was a drug that was a key part of the Federation's pacification programme. It had been developed by Forbus as a muscle relaxant. Servalan, in her guise as Commissioner Sleer, learned that at a hundred times normal dosage it would sap the will. It was first used to subjugate the population of planets the Federation reoccupied. It was used on Helotrix, with Servalan forcing Forbus to manufacture it on-site. It was delivered by medical laser, with Federation troopers adapting the native Helots in this manner. The drug was only stable for a few days before the enzyme bonds broke up. Forbus had developed an antidote that could immunise against the effects. He gave a sample to Tarrant and Dayna, who shared it with the Helot resistance. (D: Traitor)

The Federation continued to use it in the coming months, with the planet Zondor being among those where it was used. It was now used in an even greater dose, with populations being reduced to a zombie-like state. (D: Warlord)