Semax 50mg — Vial Spec, Reconstitution Math & COA

Overview of Semax 50mg Mass Specifications & Laboratory Context

Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is a synthetic heptapeptide derived from the N-terminal fragment (4-10) of adrenocorticotropic hormone (ACTH). Engineered to remove adrenocorticotropic endocrine activity while preserving central nervous system neurotrophic interactions, the peptide is routinely studied in neurobiology, cellular stress, and ischemic injury models. A 50mg vial size represents a large-format laboratory supply, ideal for facilities performing automated high-throughput screening or high-density longitudinal animal assays.

While PX1 Research offers standard catalog unit sizes such as our Semax 30mg vial format, high-mass specifications like 50mg are frequently utilized in bulk research applications. When managing a 50mg cake, precise volumetric dilution and immediate post-reconstitution aliquot strategies are critical to prevent concentration variance or peptide loss through surface adsorption and repeat thermal cycling. Researchers can audit our current catalog stock or coordinate large-batch specifications through our dedicated wholesale program.

Chemical Structure, Molecular Properties, and Sequence Integrity

Semax possesses the chemical formula C39H54N10O9S and a molecular mass of approximately 810.97 g/mol. The primary amino acid sequence—Met-Glu-His-Phe-Pro-Gly-Pro—incorporates a C-terminal Pro-Gly-Pro tripeptide sequence that significantly enhances metabolic stability against endogenous aminopeptidases and carboxypeptidases compared to native ACTH fragments.

In lyophilized form, the heptapeptide appears as a dense, white, amorphous cake. Due to the hydrophobic nature of the Phe-Pro region combined with the charged side chains of Met, Glu, and His, Semax demonstrates excellent solubility in aqueous solutions, including sterile water for injection, bacteriostatic water (0.9% benzyl alcohol), and phosphate-buffered saline (PBS, pH 7.4). For rigorous analytical validation, researchers can consult our published COA database to review mass spectrometry molecular weight verification and high-performance liquid chromatography (HPLC) purity chromatograms.

Reconstitution Mathematics for a 50mg Lyophilized Vial

Calculating precise target concentrations for a 50mg lyophilized vial requires strict accounting of diluent addition. Due to the high solute mass, volume displacement by the solid peptide cake must be evaluated when reconstituting into minimal liquid volumes. Below are standard stock concentration calculations for common diluent volumes added to a 50mg Semax vial:

1.0 mL Diluent Addition: Yields a final concentration of 50.0 mg/mL (50.0 µg/µL). This high-density concentrate is recommended primarily for stock storage before secondary dilution into working assay buffers. 2.0 mL Diluent Addition: Yields a final concentration of 25.0 mg/mL (25.0 µg/µL). Provides a manageable working viscosity for automated pipetting systems while maintaining high stock stability. 3.0 mL Diluent Addition: Yields a final concentration of 16.67 mg/mL (16.67 µg/µL). Ideal for direct diluent transfer into secondary cell culture media or multi-well plate setups.

To rapidly calculate custom volumetric dilutions or microgram-to-microliter conversions for specific microplate assays, researchers are encouraged to utilize our interactive reconstitution calculator.

Aliquot Planning and Diluent Compatibility Protocols

Handling a 50mg vial requires an organized aliquot plan. Repeated freeze-thaw cycles subject the peptide backbone to shear forces and ice-crystal formation that can trigger aggregation or amide cleavage. Once the 50mg cake is reconstituted, the primary solution should immediately be sub-aliquoted into low-binding polypropylene microcentrifuge tubes in single-use volumes (e.g., 50 µL to 200 µL).

For short-term experimental series (1–14 days), bacteriostatic water containing 0.9% benzyl alcohol acts as an effective diluent to prevent microbial contamination during repeated vial access. For cell culture assays where benzyl alcohol exhibits cytotoxicity, sterile 0.9% Sodium Chloride or isotonic PBS should be used, followed by immediate flash-freezing of aliquots at -20°C or -80°C. Further operational guidelines on handling sensitive reagents are available in our guide on peptide storage protocols.

Storage Dynamics and Thermal Stability Metrics

Lyophilized Semax 50mg vials maintain physical and chemical stability for up to 24 months when stored at -20°C in a desiccated environment. Exposure to ambient temperatures during short-term transit (up to 5–7 days) does not cause structural degradation, provided the vial is kept sealed away from direct ultraviolet light and moisture.

Upon reconstitution, the fluid stock exhibits variable stability depending on storage temperature and solvent choice: - At 2°C to 8°C (Refrigerated): Reconstituted stock in bacteriostatic water remains stable for up to 28 days. - At -20°C to -80°C (Frozen Aliquots): Reconstituted stock preserves bioactivity for 6 to 12 months. Repeated thawing must be avoided. - Room Temperature (20°C to 25°C): Reconstituted liquid undergoes gradual hydrolytic breakdown and should not exceed 24 hours of exposure.

COA Validation, HPLC Purity Testing, and Endotoxin Thresholds

Every batch of Semax supplied by PX1 Research undergoes rigorous testing in an independent, ISO 17025-accredited laboratory within the United States. Quality control protocols evaluate three primary compliance parameters: chemical purity via Reverse-Phase HPLC (RP-HPLC), molecular identity via Electrospray Ionization Mass Spectrometry (ESI-MS), and bacterial endotoxin levels via Limulus Amebocyte Lysate (LAL) assay.

Our specifications demand an HPLC purity of ≥98.0%, ensuring the absence of truncated peptide impurities or synthesis side-products. Endotoxin levels are strictly held below <0.01 EU/µg to eliminate pyrogenic interference in sensitive cell culture or animal models. Every unit delivered corresponds to a verifiable, lot-matched Certificate of Analysis accessible through our COA portal.

Selecting Optimal Fill Mass: 50mg vs 30mg Vials

Determining whether to deploy a 50mg vial or a smaller mass spec, such as our standard Semax 30mg, depends entirely on experimental design, assay frequency, and waste minimization strategies.

A 50mg mass fill is optimal for high-volume automated screening, longitudinal rodent studies requiring uniform vehicle administration across large cohorts, or central distribution facilities preparing consistent assay plates. Conversely, smaller formats like 30mg are advantageous for short-term exploratory studies, minimizing the risk of peptide loss due to accidental contamination or improper storage handling. To review all currently available mass configurations, explore our centralized catalog of all peptides.

Preclinical Mechanisms: BDNF Upregulation and Melanocortin Interactions

In vitro and animal models show that Semax interacts with several neurotrophic and neurochemical cascades. Preclinical studies suggest that Semax administration upregulates Brain-Derived Neurotrophic Factor (BDNF) and Nerve Growth Factor (NGF) mRNA expression in the hippocampus and frontal cortex. This neurotrophic stimulation is associated with enhanced neuronal plasticity and synaptic resistance to ischemic stress.

Additionally, research indicates that Semax acts as a selective agonist at melanocortin MC4 and MC5 receptors, modulating neuroinflammatory pathways without stimulating adrenal steroidogenesis. In vitro models evaluating endothelial cell cultures demonstrate that Semax regulates gene expression related to vascular tone, neuroprotection, and extracellular matrix remodeling under hypoxic conditions. Detailed reviews of these biochemical pathways are cataloged within the PX1 research hub.

Comparative Analysis: Semax, Selank, and N-Acetyl Semax Amidate

When evaluating neuropeptide candidates for preclinical neuroprotective or cognitive models, investigators frequently compare Semax to structurally or functionally related compounds such as Selank and modified derivatives like N-Acetyl Semax Amidate.

While original Semax focuses primarily on BDNF upregulation, melanocortin interaction, and ischemic tissue response, Selank—a synthetic analogue of the immunomodulatory peptide Tuftsin—demonstrates distinct regulatory effects on GABAergic signaling and interleukin-6 expression. Modified analogues, such as N-Acetyl Semax Amidate, incorporate N-terminal acetylation and C-terminal amidation designed to resist enzymatic degradation further, altering pharmacokinetic parameters in enzymatic stability assays. A detailed breakdown of structural modifications is published in our analysis of semax mechanism of action.

Quality Assurance and Dispatch Standards at PX1 Research

PX1 Research manufactures and handles all research compounds within state-of-the-art, GMP-compliant facilities located in the United States. Our stringent quality management framework ensures that every lot meets exact chemical parameters before release into inventory.

To support continuous laboratory operations, orders are dispatched same-day (Monday through Friday) from our dual distribution centers in California and Arizona. Each shipment includes protective packaging to shield lyophilized peptides from physical stress and ambient temperature extremes during transit. Researchers seeking custom filling, high-volume container options, or institution-level procurement can establish a dedicated account via our wholesale portal.