The present application includes a transdermal base formulation useful for example, for the transdermal delivery of active pharmaceutical ingredients along with a process for preparation thereof. In particular, the transdermal base formulation comprises: (a) an aqueous phase comprising water and at least one emulsion stabilizer; (b) an oil phase comprising at least one emulsifier, at least one emulsion stabilizer, at least one emollient comprising at least one flavonoid, at least one other emollient, and a terpene-rich natural butter; (c) an external phase comprising at least one terpene-rich extract or oil, at least one penetration enhancer and a phospholipid-complexed flavonoid; and optionally (d) at least one preservative phase.