Inclusion Criteria:  Male and nonpregnant, nonlactating female subjects ≥ 18 years of age. Written informed consent Health Insurance Portability and Accountability Act authorization, and local patient privacy required documentation for this study have been obtained Automated office blood pressure (AOBP) with SBP ≥ 130 mm Hg Background antihypertensive treatment of ≥ 2 drugs PRA ≤ 0.6 ng/mL Serum aldosterone ≥ 6 ng/dL Serum cortisol ≥ 18 mcg/dL  Exclusion Criteria:  1. Concomitant use of epithelial sodium channel inhibitors or mineralocorticoid receptor antagonists  3. Subjects with hypokalemia  4. Subjects with hyperkalemia  5. Subjects with serum cortisol < 3 mcg/dL  6. Subjects with serum sodium < 135 mEq/L  7. Subjects with estimated glomerular filtration rate < 60 mL/min/1.73m2  8. Subjects with type 1 or uncontrolled (hemoglobin A1c ≥ 9%) type 2 diabetes mellitus  9. Subjects with body mass index > 40 kg/m2  10. Subjects with unstable angina  11. Subjects with SBP ≥ 175 mm Hg or DBP ≥ 100 mm Hg  12. Subjects with a decrease in SBP ≥ 20 mm Hg or DBP ≥ 10 mm Hg from sitting to standing position  13. Subjects who, in the opinion of the investigator, have suspected nonadherence to antihypertensive treatment  14. Subjects who, in the opinion of the investigator, have any major medical illness or symptoms  15. Subjects who, in the opinion of the investigator, have any acute or chronic medical or psychiatric condition  16. Subjects undergoing treatment with any of the following medications:  Topical corticoids Sympathomimetic decongestants Theophylline Phosphodiesterase type 5 inhibitors NSAIDs Intramuscular steroids Estrogen Cytochromes  Strong CYP3A and CYP3A4 inducers  17. Subjects with known hypersensitivity to MLS-101 or any of the excipients  18. Subjects who are night-shift workers