Testosterone Mix 400
High-concentration testosterone blend at 400 mg/mL combining long-acting esters for reduced injection volume.
Testosterone Mix 400
Testosterone Mix 400 is a high-concentration multi-ester testosterone formulation delivering 400 mg of total testosterone per milliliter. The blended ester profile combines short, medium, and long-chain esters at carefully calibrated ratios to produce both rapid onset and sustained release from a single injection. The 400 mg/mL strength is among the highest available in pharmaceutical-grade injectable testosterone formulations, allowing for significant reduction in injection volume compared to standard single-ester preparations.
Ester Composition Strategy
The multi-ester approach exploits the differential hydrolysis kinetics of testosterone esters with varying carbon chain lengths. Shorter-chain esters (propionate, phenylpropionate) hydrolyze rapidly at the injection depot, providing elevated free testosterone within 24-48 hours of administration. Medium-chain esters (isocaproate, decanoate) provide secondary release peaks in the days following administration, while longer-chain esters (enanthate, cypionate, undecanoate) maintain extended depot release over 10-21 days. The cumulative effect is a smooth pharmacokinetic curve with reduced peak-to-trough variability compared to single-ester formulations.
Pharmacokinetic Profile
Following intramuscular administration, the staggered ester hydrolysis produces an effective composite half-life of approximately 8-12 days. The short-ester component yields initial peak free testosterone levels within 24-48 hours; medium-ester contributions sustain plasma levels through days 4-7; and the long-ester components maintain therapeutic concentrations through the second and third weeks post-injection. This profile typically allows for weekly or biweekly administration while maintaining stable serum testosterone levels.
Mechanism of Action
All testosterone esters in the formulation hydrolyze to identical free testosterone, which binds to the androgen receptor (AR) with high affinity. AR activation initiates the standard cascade of androgenic gene expression, protein synthesis upregulation, and downstream metabolic effects. A small fraction of free testosterone undergoes aromatization to 17-beta estradiol via the CYP19 aromatase enzyme — an effect that scales with serum testosterone concentration and may require consideration at high-strength formulations such as this one.
High-Concentration Formulation Considerations
Achieving 400 mg/mL of total testosterone requires careful solubility engineering. Standard cottonseed oil cannot dissolve such a high ester load alone, so our formulation incorporates ethyl oleate as a primary co-solvent alongside benzyl alcohol (2% v/v) and benzyl benzoate (10-20% v/v). The combination yields a low-viscosity injectable solution that passes through standard 22-gauge needles without excessive injection pressure or discomfort. The formulation is prepared under aseptic conditions and sterile-filtered through validated 0.22-micron polyethersulfone membranes prior to vial filling.
Quality Assurance
Each production batch of Biomedica Testosterone Mix 400 undergoes the complete pharmaceutical release testing protocol: HPLC total testosterone concentration verification (specification: 380-420 mg/mL), individual ester ratio confirmation by HPLC-UV, HPLC purity analysis (specification: ≥98% total testosterone content), sterility testing per USP <71>, bacterial endotoxin quantification by LAL assay (specification: <0.25 EU/mL), and particulate matter inspection per USP <788>. A Certificate of Analysis is issued for every production lot and is available to verified customers upon request.
Mechanism of Action
Testosterone Mix 400 is a high-strength multi-ester testosterone formulation. The blended esters hydrolyze at staggered rates, yielding sustained release of free testosterone and stable serum levels at reduced injection frequency.
Quality Assurance
Every batch of Testosterone Mix 400 produced by Biomedica undergoes the complete pharmaceutical release testing protocol before distribution. This includes HPLC compound identity confirmation and purity analysis (specification: ≥98%), concentration verification (specification: ±5% of label claim), sterility testing per USP <71>, bacterial endotoxin quantification by LAL assay (specification: <0.25 EU/mL), and particulate matter inspection per USP <788>. A Certificate of Analysis is issued for every production lot.
Authentication
Each unit of Testosterone Mix 400 carries a unique authentication code on its outer packaging. This code can be verified instantly on our Authentication page to confirm the product is genuine Biomedica stock.