This is a phrase from one of Sri Vedantha Desika's works.
Rasaayanam, which many people think to mean a chemical, actually means "means to attain". So Sowkya Rasaayanam literally translates to "means to attain sowkyam".
Sowkyam is one of those numerous words that simply cannot be translated into English or, for that matter any other language. It is a word that describes a state of mind. A state in which, one is content, happy, and at peace with himself and with the world outside.
According to Sri Vedantha Desika - the Sri Vaishnavite saint of peerless intellect, the surest means to attain sowkyam is meditation on the Divya Dampati. Money, things, people, and all the external trappings of prosperity cannot bring about certain happiness. It is only mediation on the Divya Dampati (and consequently Their grace) that can ensure sustainable and true happiness.
Great and benevolent Acharyas like the Azhwars, Sri Ramanuja and Sri Desika have provided us with the means to sowkyam. Sri Tondaradippodi Azhwars declares "Narakame swargam aakkum naamangal udaiya nambi". (The Lord with blessed Names that are capable of transforming hell into heaven)
Consequently, this means that, should we fall into a hellish situation, the surest way to redeem and extricate ourself is to meditate on the Hallowed Names of Lord Sriman Narayana. The Names that are greater than the Lord Himself.
When we meditate on the Divya Dampati with faith, their unfailing Grace attends on us and dissolves our troubles, relieves us of our suffering. The Divya Dampati, the Supreme Protectors, rush to our succour, and ensure our sowkyam. Our sins, sorrows, guilt, negative thoughts etc. are washed away in a flood of Grace and Daya.
Sri Vedantha Desikar Thiruvadigale Saranam