Pharmaceutical formulations suitable for oral administration in solid dosage forms are described. The compositions comprise an effective amount of a base salt of a compound of Formula I and a release rate controlling composition comprising a solubilizing agent, a gelling agent, and a water soluble filler； wherein Formula I is: wherein R 1 , R 2 , R 3 and R 4 are defined herein. The formulations are suitable for use in the inhibition of HIV integrase, the treatment and prophylaxis of HIV infection, and the treatment, prophylaxis and delay in the onset of AIDS.
