A controlled release aqueous emulsion is disclosed, as are its method of manufacture and use as a vehicle for delivering medicaments in liquid form. A contemplated emulsion comprises a wax containing oil-in-water emulsion having an average oil particle size of about 100 nm to about 250 nm, a pH value of about 4.5 to about 8.0 and a viscosity at 20-25 C of 1 to about 1000 cps. The oil and water phases are emulsified by an emulsifying agent that provides freedom from phase separation at a pH value of about 4.5 to about 8, while also providing phase separation at a pH value below about 2.0.