Background of Peptide Freeze Drying Technology

With the rapid development of biotechnology, proteins and other biotechnological drugs are increasingly used in the prevention and treatment of modern diseases. Because of the poor stability of protein peptide drugs and the low bioavailability of oral or other non injection routes, most protein drugs are currently administered by injection.

Statistics show that the annual growth rate of protein drug market has reached 19% in recent years. In the process of reproduction and storage of lyophilized peptide drugs, drug deactivation often occurs. Moreover, too much water can increase the probability of oxidative deterioration of protein drugs and lead to denaturation.

3 Factors Affecting the Peptide Lyophilization Preparation:

1. Temperature

Temperature is one of the most important factors affecting lyophilized preparations. The storage temperature of lyophilized preparations must be lower than its glass transition temperature. Sometimes the temperature may be too high for a moment, exceeding the glass transition temperature of the lyophilized preparation. The molecular motion of the drug accelerates, and the surface of the lyophilized preparation shrinks, agglomerates, and discolors seriously.

Note: the glass transition temperature (Tg) is the transition temperature of the material from glass state to high elastic state.

2. Residual Water Content

According to the survey of major production sites of lyophilized preparations, we found that generally, the storage time of lyophilized preparations is long when the residual water content is in the range of 4.6% -7.6%, so the residual water content of lyophilized preparations is controlled at 5% -7% to maintain stability, which is the best humidity for lyophilized preparations.

3. Type of Protective Agent of the Lyophilized Preparation Added

In the drying stage and storage stage of the production process, the drug temperature must be lower than the glass temperature. In order to ensure that the drug temperature is lower than the glass temperature in the drying process, shorten the drying time and avoid waste, the best way is to add a protective agent with higher glass temperature.

What is freeze-drying / lyophilization?

Freeze drying, the full name of vacuum freeze drying, referred to as freeze drying, refers to a technology that pre cools materials (such as peptides) containing a large amount of water, freezes them into solids below the freezing point, and sublimates ice directly under vacuum conditions, so as to remove water and obtain dry products. Because sublimation is used to remove moisture, it is also called sublimation drying.

Peptide lyophilizer:

Freeze drying has the following 7 advantages:

1、 Freeze drying is carried out at low temperature, so it is especially suitable for many heat sensitive substances. Such as active proteins, peptides and microbial preparations.

2、 When drying at low temperature, the loss of some volatile components in the material is very small, which is suitable for drying some chemical products, drugs and food.

3、 In the freeze-drying process, the growth of microorganisms and the role of enzymes can not be carried out, so it can maintain the original properties.

4、 Drying can remove more than 95-99% of moisture, and the dried product can be preserved for a long time without deterioration.

5、 Because it is dried in the frozen state, the volume is almost unchanged, the original structure is maintained, and the concentration phenomenon will not occur.

6、 Because the drying is carried out under vacuum, some substances that are easy to oxidize are protected.

7、 The dried material is loose and porous, spongy, and dissolved rapidly and completely after adding water, almost immediately restoring its original properties.

Freeze drying technology is widely used in pharmaceutical industry, food industry, scientific research and other departments.

Peptide Lyophilization Process and Optimization

There are five steps for peptide lyophilization: preparation of drug solution, freezing, first drying (sublimation), second drying (analysis), and sealed storage.

(1) Prepare the solution:

It is generally prepared into a dilute solution containing 4%~15% of solid substances. If the solid content is too low, during the drying process, the drug particles cannot adhere to the substrate, and will be carried by the escaping steam to the plug of the vial, or even to the vacuum chamber.

(2) Freezing

It is a constant pressure cooling process, so that the liquid medicine freezes into a solid with the decrease of temperature; Most solvents (more than 95%) are frozen into solids to form an optimal ice crystal and promote the diffusion of steam from the solid skeleton.

The freezing process is divided into three stages: cooling stage, phase transformation stage and solidification stage.

The temperature of the freeze-drying box should be reduced to about -50 ℃ in advance, and the pre freezing temperature should generally be 10 ℃~20 ℃ below the common melting point of drugs. The pre freezing time is usually 0.5h~2h. After the medicine solution is put into the freeze-drying box, a certain amount of inert gas can be filled to maintain the vacuum stability.

(3) Sublimation drying: 

it is mainly to remove the free water (ice) formed during the freezing stage of the drug, about 80%~90% of the water.

First, constant temperature and pressure should be reduced, and then under the condition of air extraction, constant pressure and temperature should be raised to sublimate the solid water.

The sublimation temperature at this stage should be close to the melting point temperature, and should be 2~5 ℃ below the co melting point temperature. If it is too low, the sublimation speed will be reduced. The drying rate can be improved by vacuum degree, cold trap temperature, shelf and medicine temperature control. The control standard of drug temperature is shelf temperature control. The drug temperature should be less than 20 ℃ during sublimation drying.

(4) Analysis and drying:

After sublimation and drying, all ice crystals in the material will leave many holes, and about 10% of the water will remain. Desorption and re drying is mainly to remove unfrozen bound water (adsorbed on the dry filter cake surface), reduce the water content and maintain it at about 2%, so as to obtain dry materials. The temperature is generally set at 25~40 ℃.

(5) Sealed storage

After the freeze-dried products are removed from the freeze-drying box, they should be sealed and stored in time, otherwise they are easy to absorb moisture and shrink after contacting with air.

FAQs:

1. Definition of Peptide?

Peptide is a kind of substance which is the same as protein in amino acid composition and connection mode, but different from protein in some properties. Compared with protein, peptide is simpler in structure.

All biological cells can synthesize peptides, but they are also regulated by various peptides. The lyophilized injectable preparations of polypeptide bulk drugs play an important role in all aspects, especially in medicine. The further research of lyophilized injectable preparations of peptide bulk drugs is particularly important.

2. Preservation of Lyophilized Peptides

Peptides marked with "freeze-dried preservation" should be preserved under frozen conditions, and the best temperature is below -20 ℃. Its activity can be maintained for many years.

When using dry frozen products, the container should be raised to room temperature in the fresh drying oven before opening the lid- For products at 20 ℃, this process takes one hour or longer, depending on the warranty. Otherwise, when the container is opened, water vapor will enter, causing condensation and reducing stability. Once it is opened, it should be weighed quickly and sealed immediately to avoid deliquescence, especially for hydrophilic peptides.

3. Preservation of Dissolved Peptides

The stability of peptide solution is much worse than that of dry powder. In order to obtain better results, the following principles should be followed:

1. Divide into small packages to avoid repeated freezing and thawing. How much to use and how much to unfreeze;

2. Dissolve in ph5-7 sterile buffer and store at -20 ℃;

3. Since bacteria can degrade peptides, bacteria should be filtered before storage;

4. Peptides containing Cys, met, try, Glu and ASP are easy to oxidize, so they should be stored in an environment without oxidants

4. Research and Development of Peptide Drugs

The traditional polypeptide drugs are mainly polypeptide hormones. In recent years, the development of polypeptide drugs has developed to various fields of disease prevention and treatment. The following are the applications of freeze-dried preparations of polypeptide drugs:

1.Peptide Vaccine

Peptide vaccine is one of the most important aspects in the field of vaccine research. At present, a large number of research and development of viral peptide vaccine have been carried out in the world. In 1999, foreign scholars screened a polypeptide from the outer membrane protein E2 of hepatitis C virus (HCV), which can stimulate the body to produce protective antibodies.

2 Peptides for Cardiovascular Disease

It has been found that small molecular peptides are effective components in many plants, such as lowering blood pressure, regulating blood lipid, hemolytic thrombus and so on. Therefore, the discovery and extraction of new active peptides from plants and the development of improved peptides have become the research direction of peptide drugs.

3 Anti Tumor Peptide

After scientific research, many genes related to tumor and regulatory factors that affect tumor have been found. Therefore, some specific polypeptides specific to these genes and regulatory factors have been screened to inhibit tumor.

About Omizzur Biotech

Omizzur is a biotech company engaged in custom peptide synthesis, peptide impurities, amino acid derivatives, and peptide reagents, providing professional services for pharmaceutical research and development enterprises, generic drug companies, laboratories worldwide.

Inquiry : [email protected] | www.omizzur.com