Tadalafil Research Grade Compound (PDE5 Inhibitor) Supplier — UPOR Biotech
Tadalafil is a potent, highly selective phosphodiesterase 5 (PDE5) inhibitor — a fused tetracyclic small-molecule API that potentiates cGMP-mediated smooth-muscle relaxation and vascular vasodilation. With an IC50 of 1.8 nM and >2000-fold selectivity over PDE1-4, it is the defining reference standard for ED, PAH, and BPH pharmacology and cGMP-signaling research. CAS 171596-29-5, C₂₂H₁₉N₃O₄, MW 389.40 g/mol. Research Grade (RUO) — bulk API supplier from UPOR Biotech.
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Tadalafil (CAS 171596-29-5, C₂₂H₁₉N₃O₄, MW 389.40 g/mol) is a potent and highly selective phosphodiesterase 5 (PDE5) inhibitor — a fused tetracyclic small molecule (a pyrazino[1′,2′:1,6]pyrido[3,4-b]indole-1,4-dione derivative) first approved in 2003 (referenced as Cialis; supplied here as an RUO reference standard only). Tadalafil inhibits PDE5 with an IC50 of 1.8 nM, preventing the hydrolysis of cyclic GMP (cGMP) and potentiating NO-mediated smooth-muscle relaxation and vasodilation. It exhibits >2000-fold selectivity over PDE1, PDE2, PDE3, and PDE4 and approximately 1000-fold selectivity over PDE6 — a selectivity profile that underlies its long duration of action and distinct pharmacodynamic character. This mechanism positions tadalafil as the pharmacologically defining long-acting PDE5 inhibitor for erectile dysfunction (ED), pulmonary arterial hypertension (PAH), and benign prostatic hypertrophy (BPH) research, and for studies of the cGMP/NO signaling pathway in vascular and smooth-muscle pharmacology.
As a Research Grade (RUO) reference compound, UPOR Biotech supplies tadalafil as a single-enantiomer, ≥98% HPLC-purity drug substance for laboratory and analytical use. It is applied across ED pharmacology research, PAH studies, BPH research, PDE isoform selectivity assays, and analytical reference-standard and method development. Research Use Only (RUO) — not for human diagnostic or therapeutic use. Every lot is released with a Certificate of Analysis (HPLC assay, impurity profile, heavy metals ≤10 ppm), MSDS, HPLC chromatogram, and full batch traceability, supported by ISO 9001, cGMP, and FDA facility registration. Supplied in 1 g, 5 g, 10 g, and 50 g sealed pharmaceutical-grade containers with a 3-year shelf life.
Tadalafil vs Sildenafil — Long-Acting PDE5 Inhibitor vs Short-Acting
When comparing tadalafil vs sildenafil, both are potent PDE5 inhibitors, but they differ markedly in pharmacokinetics and isoform selectivity. Tadalafil has a longer elimination half-life (~17.5 h) versus sildenafil (~3-5 h), producing a sustained duration of action with no significant food interaction. Tadalafil also has a distinct PDE6-selectivity profile (~1000-fold selectivity over PDE6 versus sildenafil’s ~10-fold), translating to a lower incidence of visual disturbance in clinical use. Both serve as reference compounds in cardiovascular and urology pharmacology — tadalafil for long-acting PDE5 inhibition and cGMP-signaling studies, sildenafil for short-acting inhibition kinetics. UPOR Biotech supplies tadalafil as a Research Grade (RUO) reference standard for laboratory research.
Technical Specifications
| Property | Specification |
|---|---|
| Product Name | Tadalafil — Research Grade (RUO) PDE5 Inhibitor Reference Compound |
| Synonyms | Tadalafil; IC-351; GF196960 |
| CAS Number | 171596-29-5 |
| Molecular Formula | C₂₂H₁₉N₃O₄ |
| Molecular Weight | 389.40 g/mol |
| IUPAC Name | (6R,12aR)-6-(1,3-Benzodioxol-5-yl)-2,3,6,7,12,12a-hexahydro-2-methylpyrazino[1′,2′:1,6]pyrido[3,4-b]indole-1,4-dione |
| Compound Class | Small-molecule PDE5 inhibitor — fused tetracyclic pyrazino[1′,2′:1,6]pyrido[3,4-b]indole-1,4-dione derivative |
| Stereochemistry | Single enantiomer (6R,12aR) — enantiomerically pure drug substance |
| Mechanism of Action | Selective PDE5 inhibition — prevents cGMP hydrolysis, potentiates NO-mediated smooth-muscle relaxation and vasodilation |
| IC50 (PDE5) | 1.8 nM |
| Isoform Selectivity | >2000-fold over PDE1-4; ~1000-fold over PDE6 |
| Biological Half-Life | ~17.5 h — long-acting PDE5 inhibitor |
| Purity (HPLC) | ≥98.0% |
| Appearance | White to off-white crystalline solid |
| Melting Point | ~298–303°C |
| Optical Rotation | Single enantiomer — consistent [α]D within lot |
| Solubility | DMSO ≥52 mg/mL; sparingly soluble in aqueous buffer |
| Heavy Metals | ≤10 ppm |
| Residual Solvents | ICH Q3C compliant |
| Storage | 2–8°C, protected from light and moisture, tightly sealed |
| Grade | Research Grade (RUO) |
| Applications | ED pharmacology, PAH studies, BPH research, cGMP/NO signaling, PDE isoform selectivity assays, analytical reference standard |
| Certifications | ISO 9001, cGMP, FDA facility registration |
| Packaging | 1 g / 5 g / 10 g / 50 g sealed pharmaceutical-grade containers |
| Shelf Life | 3 years |
| Disclaimer | Research Use Only (RUO) — not for human diagnostic or therapeutic use |
Key Benefits — Tadalafil Research Grade
Potent Selective PDE5 Inhibition — IC50 1.8 nM
Tadalafil inhibits PDE5 with a potent IC50 of 1.8 nM, blocking cGMP hydrolysis at the catalytic site. This high potency delivers pronounced NO-mediated smooth-muscle relaxation and vasodilation at low concentrations, making tadalafil the benchmark long-acting PDE5 inhibitor for pharmacology research.
IC50 1.8 nMcGMP-Mediated Vasodilation Potentiation
By preventing cGMP degradation, tadalafil potentiates the NO/cGMP signaling pathway — amplifying nitric-oxide-triggered relaxation of vascular and corpus-cavernosum smooth muscle. Ideal for mechanistic studies of the cGMP second-messenger cascade in cardiovascular and urology pharmacology.
cGMP Potentiation>2000-Fold PDE Isoform Selectivity
Tadalafil is >2000-fold selective for PDE5 over PDE1-4 and ~1000-fold selective over PDE6 — a cleaner isoform profile than other PDE5 inhibitors. This selectivity reduces off-target PDE activity and supports high-confidence PDE isoform selectivity assays.
>2000-fold Selective≥98% HPLC Purity Reference Standard
≥98.0% HPLC purity as a single-enantiomer drug substance with full impurity profiling and heavy metals ≤10 ppm. A dependable analytical reference standard for method development, calibration, and QC with complete COA documentation.
≥98% HPLCApplications
Erectile Dysfunction (ED) Pharmacology Research
Study of PDE5 inhibition on corpus-cavernosum smooth-muscle relaxation and NO/cGMP-dependent erectile responses using the reference long-acting PDE5 inhibitor.
Pulmonary Arterial Hypertension (PAH) Studies
Research on cGMP-mediated pulmonary vasodilation and vascular remodeling, replicating PDE5-inhibitor pharmacology in experimental models of PAH.
Benign Prostatic Hypertrophy (BPH) Research
Investigation of PDE5 inhibition on detrusor and prostatic smooth-muscle tone and lower-urinary-tract symptom pharmacology.
cGMP/NO Signaling Pathway Studies
Mechanistic exploration of the nitric-oxide/cGMP second-messenger cascade, vasodilation, and endothelial function using a potent pathway probe.
PDE Isoform Selectivity Assays
Validation of PDE5-selective pharmacology against PDE1-6 panels, leveraging tadalafil’s >2000-fold isoform selectivity.
Analytical Reference Standard & Method Development
HPLC, LC-MS, and dissolution method development, impurity profiling, and QC calibration using a ≥98% HPLC-purity reference substance.
Frequently Asked Questions
Tadalafil is a potent, highly selective PDE5 inhibitor with an IC50 of 1.8 nM. By blocking phosphodiesterase 5, it prevents the breakdown of cGMP, potentiating NO-mediated smooth-muscle relaxation and vasodilation. This cGMP-potentiation mechanism underlies its long-acting pharmacology in vascular and urology research.
Both are PDE5 inhibitors, but tadalafil has a longer elimination half-life (~17.5 h) versus sildenafil (~3-5 h) and a distinct PDE6-selectivity profile (~1000-fold over PDE6) that reduces off-target PDE6 activity. Tadalafil is the long-acting reference standard; sildenafil represents the short-acting PDE5 inhibitor class.
Tadalafil is used across ED pharmacology research, PAH studies, BPH research, cGMP/NO signaling pathway studies, and PDE isoform selectivity assays, and as an analytical reference standard for method development. Its >2000-fold PDE5 selectivity makes it the benchmark long-acting PDE5 inhibitor for cardiovascular and urology pharmacology.
Store at 2-8°C, protected from light and moisture, in a tightly sealed container. Prepare DMSO stock solutions (solubility ≥52 mg/mL) under inert atmosphere, aliquot to avoid repeated freeze-thaw cycles, and handle using standard laboratory PPE for pharmaceutical drug substances.
Every lot ships with a COA (HPLC assay, impurity profile, heavy metals ≤10 ppm), MSDS, HPLC chromatogram, and full batch traceability, supported by ISO 9001, cGMP, and FDA facility registration. Supplied as a Research Grade (RUO) compound — not for human diagnostic or therapeutic use.