Title:
Synthetic Love
Description:
Main character is a scientist who has invented a way to increase sexual desire and sensitivity in women. There is a short-term memory loss. In other words, a person who has taken the medicine enjoys vivid sexual sensations but then can not remember what has happened. The main character tries to get rid of this side effect. 
He works in his mansion with a lab up in the mountains. There are three girls there with him: a lab assistant, a housemaid and a gardener. He carries out experiments on them: gives some versions of the medicine to the girls and has them with them. 
But something went wrong ...