The present invention provides minicircle nucleic acid vector formulations for use in administering to a subject, wherein the minicircle nucleic acid vectors include a polynucleotide of interest, a product hybrid sequence of a unidirectional site-specific recombinase, and are devoid of plasmid backbone bacterial DNA sequences. Also provided are methods of producing the subject formulations as well as methods for administering the minicircle nucleic acid vector formulations to a subject. The subject methods and compositions find use in a variety of different applications, including both research and therapeutic applications.