Description

Technical Parameters

Introduction

peptides

product-1400-1400

Products Description

### 1.Systematic analysis of human chorionic gonadotropin (HCG 5000 IU) peptide preparations

**Human chorionic gonadotropin (HCG)** is a glycoprotein hormone secreted by placental syncytiotrophoblast cells, which maintains corpus luteum function and promotes progesterone secretion in early pregnancy. Its peptide preparations (such as HCG 5000 IU) are prepared by genetic recombination technology or natural extraction and are widely used in reproductive medicine, endocrine research and sports medicine. HCG has a molecular weight of about 36,000-40,000 Daltons and is composed of α (92 amino acids) and β (145 amino acids) subunits bound by non-covalent bonds, of which the β subunit gives it biological specificity.

#### 2. Chemical structure and classification

1. **Chemical structure characteristics**

- **Subunit composition**: The α subunit is homologous to LH, FSH, and TSH, and the β subunit contains a unique carboxyl terminal sequence (CTP), which determines the receptor binding specificity.

- **Glycosylation modification**: Contains 4 N-glycosylation sites (2 for α subunit and 2 for β subunit), which affects the half-life and biological activity.

- **Disulfide bonds**: The structure between α and β subunits is stabilized by 11 disulfide bonds to ensure the integrity of the molecular conformation.

2. **Classification and preparation methods**

- **Naturally extracted HCG**: Purified from the urine of pregnant women, contains a small amount of impurity protein (such as urokinase), low cost but large batch differences.

- **Recombinant HCG (rHCG)**: Produced through a CHO cell expression system, with a purity of >99%, low immunogenicity, and better stability.

- **Functional classification**:

- **Pharmaceutical grade**: Meets GMP standards and is used for clinical ovulation induction or cryptorchidism treatment.

- **Research grade**: High-purity lyophilized powder, suitable for in vitro experiments or animal models.

- **Sports supplement** (non-compliant use): Illegal use to stimulate testosterone secretion, posing health risks.

#### 3. Advantages and clinical application advantages

1. **High efficiency and targeting**

- Simulates the effect of LH, directly activates the LH/hCG receptors of testicular interstitial cells or ovarian granulosa cells, and promotes the synthesis of testosterone and progesterone.

- The half-life is as long as 24-36 hours (natural LH is only 20 minutes), reducing the frequency of administration.

2. **Purity and safety**

- Recombinant HCG has no animal-derived contamination, reducing the risk of allergic reactions.

- Strict quality control indicators (such as HPLC purity detection, mass spectrometry analysis) ensure batch consistency.

3. **Multi-scenario application**

- **Reproductive medicine**: Treatment of female anovulatory infertility and male hypogonadotropic hypogonadism.

- **Assisted reproductive technology (ART)**: Used in combination with FSH to induce follicle maturation.

- **Pediatrics**: Correction of cryptorchidism and promotion of testicular descent.

- **Scientific research field**: Study of embryo implantation mechanism or tumor markers (such as trophoblastic tumors expressing HCG).

#### 4. Physical and chemical properties

1. **Basic parameters**

- **Molecular weight**: 36.7 kDa (recombinant HCG).

- **Isoelectric point (pI)**: 4.5-5.2, slightly different due to the degree of glycosylation.

- **Solubility**: Easily soluble in pH 6.5-7.5 buffer, usually with mannitol or sucrose as excipients before lyophilization.

2. **Spectral characteristics**

- **UV absorption peak**: 280 nm (tyrosine and tryptophan residues), extinction coefficient of about 1.7 L/(g·cm).

- **Fluorescence characteristics**: excitation wavelength 280 nm, emission wavelength 340 nm, used for quantitative analysis.

3. **Stability**

- **Thermal stability**: activity loss >50% after 3 days of storage at 25℃ in liquid state, freeze-dried product can be stored for 2 years at -20℃.

- **Photosensitivity**: exposure to ultraviolet light can easily lead to disulfide bond breakage, so it needs to be stored away from light.

- **Storage after reconstitution**: use within 24 hours at 2-8℃, avoid repeated freezing and thawing.

#### 5. Color and appearance characteristics

1. **Physical form**

- **Lyophilized powder**: white or off-white loose solid, no visible particles.

- **After reconstitution**: clear to slightly opalescent solution (related to excipients), no precipitation or suspended matter.

2. **Clinical significance of color change**

- **Yellow or brown**: may be degraded due to oxidation or high temperature, indicating loss of activity.

- **Turbidity or precipitation**: protein aggregation or microbial contamination, prohibited for use.

#### 6. Detailed explanation of application areas

1. **Reproductive health**

- **Female**:

- Inducing ovulation: 5000-10,000 IU single injection triggers final maturation of oocytes.

- Corpus luteum support: enhance endometrial receptivity and improve implantation rate.

- **Male**:

- Treatment of hypogonadotropic hypogonadism: 2000-4000 IU/time, 2-3 times a week.

- Reversal of testicular atrophy: restore endogenous testosterone secretion after long-term steroid abuse.

2. **Scientific research application**

- **Embryology**: study the regulatory effect of HCG on embryonic stem cell differentiation.

- **Oncology**: As a serum marker for choriocarcinoma and hydatidiform mole (β-HCG detection).

- **Pharmacology**: Evaluate the effects of new GnRH analogs on the gonadal axis.

3. **Controversial Uses**

- **Exercise Muscle Building**: Enhances muscle synthesis by stimulating testosterone secretion, but is listed as a banned drug by WADA.

- **Weight Loss**: The "HCG Weight Loss Method" combined with a very low-calorie diet lacks evidence-based support and is risky.

####7. Storage and Transportation Specifications

1. **Storage Conditions**

- **Unopened freeze-dried powder**: Below -20℃, humidity <60%, avoid repeated freezing and thawing.

- **Reconstituted solution**: Store at 2-8℃, it is recommended to add an antibacterial agent (such as benzyl alcohol).

2. **Transportation Requirements**

- Dry ice transportation (-78℃) or refrigerated truck (2-8℃), avoid severe vibration.

#### 8. Safety and side effects

1. **Contraindications**

- Allergy to HCG or excipients, prostate cancer, precocious puberty, unexplained vaginal bleeding.

2. **Common side effects**

- **Female**: Ovarian hyperstimulation syndrome (OHSS), multiple pregnancy.

- **Male**: Acne, edema, breast development (elevated estrogen levels).

3. **Long-term risks**

- Antibody formation (natural HCG incidence is about 5%), gonadal function suppression (in case of abuse).

#### 9. Future development direction

1. **Structural modification**: Develop long-acting HCG analogs (such as PEGylation) to extend half-life.

2. **Targeted delivery**: Nanocarrier technology increases local drug concentration in the ovaries and reduces systemic exposure.

3. **Integrated diagnosis**: Combined with HCG rapid test kit, personalized adjustment of ART regimen.

### Conclusion

As a representative of peptide drugs, HCG 5000 IU peptide preparations continue to play a key role in medicine and scientific research with their clear target mechanism and wide application scenarios. However, their abuse risks and ethical disputes also need to be paid attention to. In the future, with the advancement of bioengineering technology, HCG derivatives are expected to achieve greater breakthroughs in safety and efficacy.