Clinical Trials

Ruboxistaurin (LY333531) has been evaluated across multiple clinical trials ranging from early to late phases to investigate metabolic and vascular conditions, primarily diabetic retinopathy, diabetic neuropathy, type 1 and type 2 diabetes mellitus, heart failure, and hyperpigmentation. Supported by industry sponsors including Eli Lilly and Company and Chromaderm, Inc., as well as academic institutions such as the Joslin Diabetes Center, the majority of these studies are completed. Although late-stage trials evaluating diabetic complications reached completion, certain early-phase heart failure investigations were withdrawn.

NCT Number Recruitment Conditions Sponsor/Collaborators Start Date Phases
NCT05511948 COMPLETED
Hyperpigmentation
DermBiont, Inc.
 2022-08-18 PHASE2
NCT02769611 WITHDRAWN
Heart Failure
University of Tennessee
 2017-06-28 PHASE1; PHASE2
NCT00133952 COMPLETED
Diabetic Macular Edema
Chromaderm, Inc.
 2005-08 PHASE3
NCT00090519 COMPLETED
Diabetic Retinopathy
Chromaderm, Inc.
 2004-02 PHASE3
NCT00266695 COMPLETED
Diabetic Retinopathy
Chromaderm, Inc.
 2006-01 PHASE3
NCT00297401 COMPLETED
Diabetes Mellitus, Type 1
Chromaderm, Inc.
 2006-03 PHASE3
NCT00761852 COMPLETED
Type 1 Diabetes Mellitus; Type 2 Diabetes Mellitus
Brigham and Women's Hospital
 1999-05 PHASE2; PHASE3
NCT00297401 Completed
Diabetes Mellitus Type 1
Chromaderm Inc.|Heart and Stroke Foundation of Canada
 2006-03 Phase 3
NCT00604383 COMPLETED
Diabetic Retinopathy
Chromaderm, Inc.
 2001-03 PHASE3
NCT00190970 Completed
Diabetic Neuropathy
Chromaderm Inc.
 2004-10 Phase 2
NCT00044148 COMPLETED
Diabetic Nephropathy
Chromaderm, Inc.
 2002-07-16 PHASE2
NCT00482976 Completed
Diabetes Mellitus
Chromaderm Inc.|Joslin Diabetes Center
 2003-12 Phase 2
NCT00552227 COMPLETED
Diabetes Mellitus
Chromaderm, Inc.
 2002-09 PHASE1
NCT00044395 COMPLETED
Diabetic Neuropathies; Diabetes Mellitus, Insulin-Dependent; Diabetes Mellitus, Non-Insulin-Dependent
Eli Lilly and Company
 2002-07 PHASE3
NCT00044421 COMPLETED
Diabetic Neuropathies; Diabetes Mellitus
Eli Lilly and Company
 2002-07 PHASE3
NCT00482976 COMPLETED
Diabetes Mellitus
Chromaderm, Inc.
 2003-12 PHASE2
NCT00044408 COMPLETED
Diabetic Neuropathies; Diabetes Mellitus, Insulin-Dependent; Diabetes Mellitus, Non-Insulin-Dependent
Chromaderm, Inc.
 2002-07 PHASE3
NCT00190970 COMPLETED
Diabetic Neuropathy
Chromaderm, Inc.
 2004-10 PHASE2

(data from https://clinicaltrials.gov, updated on 2023-10-25)

Check the Ruboxistaurin (LY333531) Hydrochloride product page for in-depth specifications, including solubility, stock solutions, MOA, and working concentrations.

Compliance for Clinical Use

Mechanism and Biochemical Profile

Ruboxistaurin acts as a competitive, reversible inhibitor of protein kinase C beta isoforms PKCβ1 and PKCβ2, blocking downstream vascular endothelial growth factor signaling and cellular oxidative stress pathways. By dampening hyperactive protein kinase C beta signaling to preserve microvascular endothelial integrity, this targeted inhibition addresses the underlying pathophysiology of diabetic microvascular complications such as diabetic retinopathy and diabetic neuropathy.

Appendix RUO and cGMP Quality Standards

Quality Dimension RUO (Research Use Only) cGMP (Current Good Manufacturing Practice)
Clinical Applicability Prohibited in human clinical trials or medical diagnostics. Mandatory for human clinical trials (Phase I–III) and therapies.
Regulatory Status Non-regulated grade; exempt from drug manufacturing laws. Legally enforced by health authorities (e.g., FDA, EMA, NMPA).
Facility Environment Unclassified analytical or research laboratories. Validated Cleanrooms (ISO Class 5–8) with continuous monitoring.
Quality Control Basic purity and activity testing. Rigorous safety release testing (Sterility, Endotoxin, Mycoplasma).
Process Validation Basic equipment calibration; no process validation required. Full qualification (IQ/OQ/PQ) and complete batch records.
Quality Assurance Vendor self-declared without required formal QMS. Mandatory QA/QC unit, Change Control, CAPA, and vendor audits.
Regulatory Impact High risk of IND rejection if used as a critical raw material. Required for IND/NDA filings, supported by Drug Master Files (DMF).

Footnotes

Regulatory Note: Governed by FDA (21 CFR Parts 210/211/312), EMA (EudraLex Vol 4), ICH Guidelines (E6/Q7/Q9/Q10), and compendial standards (USP <71>/<85>/<1043>).

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Note: Technical data last updated: Sep 1, 2026.