This is a Phase 2 study designed to assess the ability of RP-G28 to improve lactose digestion and tolerance.

Lactose intolerance is a common gastrointestinal (GI) disorder that develops in lactose maldigesters when consuming too much lactose or when lactose is added to a previously low-lactose diet. Lactose intolerance is characterized by one or more of the cardinal symptoms that follow the ingestion of lactose-containing foods. These symptoms include; abdominal pain/cramps, bloating, flatulence [gas] and diarrhea. As such, most lactose intolerant individuals avoid the ingestion of milk and dairy products, while others substitute non-lactose containing products in their diet.

Based on the health implications from insufficient calcium intake over a lifetime, including increased risk of osteoporosis and hypertension, there is need in the medical community for a tolerable and convenient treatment that allows for all levels of milk and dairy product consumption in people suffering from mild to severe lactose intolerance. This study will evaluate a treatment that provides a simplified dosing regimen as well as the potential for extended relief from symptoms following a limited therapy regimen.

Inclusion Criteria:

• Male and female subjects. Female subjects must be non-pregnant and non-lactating.
• 18 to 64 years of age inclusive at Screening
• Current or recent history of intolerance to milk and other dairy products
• Acceptable Baseline Lactose Intolerance Symptom Scores
• Acceptable Result on Baseline Hydrogen Breath Test
• Subjects must agree to refrain from all other treatments and products used for lactose intolerance during the study

Exclusion Criteria:

• Disorders known to be associated with abnormal GI motility
• History of surgery that alters the normal function of the gastrointestinal tract
• Past or present; organ transplant, chronic pancreatitis, pancreatic insufficiency, symptomatic biliary disease, Celiac disease, inflammatory bowel disease (IBD), ulcerative colitis, Crohn's disease, irritable bowel syndrome (IBS)
• Active gastric or duodenal ulcers or history of severe ulcers
• Diabetes mellitus (type 1 or type 2)
• Congestive Heart Failure
• History of Human Immunodeficiency Virus (HIV), Hepatitis B or C
• Use of concurrent therapy(ies) for symptoms of lactose intolerance
• Uncontrolled BP defined as sitting systolic blood pressure (SBP) ≥160 mmHg or diastolic blood pressure (DBP) ≥95 mmHg at Visit 1
• History of ethanol abuse in the past 12 months
• History of drug abuse within 12 months
• History or presence of malignancy within the past 5 years (except basal cell or squamous cell carcinoma removed from a sun-exposed area)
• Use of any investigational drug or participation in any investigational study within 30 days prior to Screening