Inclusion Criteria:
- Patients with the following may enter:
Clinical signs and symptoms (footpain, numbness, tingling, weakness, etc.) of symmetrical distal Diabetic Sensorimotor Polyneuropathy with diagnosis by Nerve Conduction Tests and/or Quantitative Sensory Test.
- 18 to 70 years old of either sex and any race
- Type I or Type II, insulin-dependent or non insulin-dependent diabetes for at least six months prior to study entry
- Healthy in general
- No hospitalizations for diabetic control or episodes of ketoacidosis for three months prior to screening
- Female patients of childbearing potential must have a negative serum pregnancy test
Exclusion Criteria:
- Known non-diabetic causes of neuropathic symptoms
- Diabetic patients with no neuropathy or severe neuropathy
- Used any Aldose Reductase Inhibitors within one year of screening
- Clinically significant illness including unstable cardiac, pulmonary, hematologic, hepatic, renal, or neoplastic disease
- A history of systemic carcinoma within five years of screening
- A history of epilepsy or serious head injury
- A history or evidence of drug or alcohol abuse
- Test positive at screening for hepatitis B surface antigen or hepatitis C antibody or have a history of a positive result, or patients with evidence of significant hepatic insufficiency
- A history of known or suspected diagnosis of AIDS, or have tested seropositive for HIV antibody or antigen previously