A Better Pill to Swallow

Ash and friends encounter a man named Old Man Shuckle who uses Shuckle to produce medicine. There is an especially rare one that has a purple shell that has a special juice that it produces. Team Rocket steal the Shuckle and drink the juice which makes all of the pokemon in the area fall in love with them. Ash and friends set out to find them and get the Shuckle back.