Fat milk production and process

Fat emulsions are an important part of parenteral nutrition and are energy supplements. Clinically, in addition to providing the energy required for metabolism, the fat emulsion also provides the body with polyunsaturated fatty acids required for the metabolism of biofilms and biologically active substances, preventing and correcting the lack of essential fatty acids in the body. At present, the fat emulsion commonly used in clinical practice is a long-chain triglyceride (LCT) fat emulsion. The basic prescription is based on soybean oil (LCT) , using refined lecithin as an emulsifier and glycerol as an isotonic agent. High pressure homogenization. Many years of clinical application studies have found that high-dose or long-term continuous use of long-chain fat emulsions can cause hyperlipidemia, damage to the immune system and affect the function of important organs such as the reticuloendothelial system and liver [1]. Germany B.Braun company on the basis of long-chain fatty emulsion in-depth research, in the mid-1980s created a new generation of fat emulsion - medium / long-chain fat emulsion injection (Lipofundin MCT / LCT). The medium / long-chain fat emulsion injection uses the body's more easily absorbed medium chain triglyceride (MCT) as an energy source while retaining part of the LCT as a source of essential fatty acids. The group fully utilized the characteristics of MCT in the body, such as easy hydrolysis, rapid oxidation and simple metabolic process, which made up for the deficiency of LCT fat emulsion. Compared to LCT fat emulsions, medium / long-chain fat emulsions provide faster energy, better protein synthesis, good liver tolerance and nutritional effects that maintain normal immune function. In foreign countries, medium / long-chain fat emulsion injections have been commonly used for clinical nutritional support. The product entered the Chinese market in 1991 , and its exact clinical nutritional effects have been confirmed by domestic clinical application research and listed as a national medical insurance class A drug. In order to speed up the development of China's intravenous nutrition business and support domestic varicose nutrition varieties, we have successfully developed medium / long chain fat emulsion injection. The research content of the preparation process will now be reported as follows.

　　 1 prescription

　　 11 10% / long chain fat emulsion injection injectable formulation consisting of soybean oil 50 g, injection medium chain triglycerides 50 g, injectable lecithin 12 g, glycerol injection 25 g, water for injection was added to 1000 mL .

　　 1.1 The prescription is based on the prescription of the foreign import license medium / long-chain fat emulsion injection.

　　 1.2 The role of each component in the prescription Soybean oil and medium chain triglycerides are the main components, lecithin is an emulsifier, and glycerol is an isotonic regulator.

　 　 2 emulsification process optimization experiment

The optimization experiment scheme of the emulsification process is based on the preparation process of the long-chain fat emulsion injection, combined with the characteristics of the medium / long-chain fat emulsion injection, and the orthogonally tested method is used to select the most influential process conditions to determine the applicable. Preparation process.

　　 2.1 Experimental material and instruments injectable medium chain triglycerides (CONDEA Company, Germany), soybean oil for injection (Germany LiPoid Corporation), lecithin for injection (Germany LiPoid Corporation), glycerin for injection (Shan Ning amino acids Ltd.). Experimental high pressure homogenizer, Coulter particle analyzer, acidity meter, experimental glass instrument set.

　　 2.2 Experimental method The core technology of the preparation process of fat emulsion is the emulsification process. According to the experience of developing and producing long-chain fat emulsion injection and the characteristics of each component in medium / long-chain fat emulsion injection, various factors that may have a great influence on the particle size and distribution of the milk during the preparation process are listed. And level , select the L9 (34) orthogonal table [2] design experiment. Using the distribution of the milk particles as a judgment index, the distribution of the experimental emulsion particles in each group was measured by a Coulter particle analyzer. The data processing is based on the percentage of particles above 1 μm and the percentage of particles above 0.5 μm as the index [3]. The small value indicates that the large particles are small and the milk particles are evenly distributed ( see Table 1 for the level of each factor ) .

Table 1 factor level table (omitted)

　　 2.3 The experimental results are shown in Table 2 .

Table 2 L9 (34) test plan and experimental results table (omitted)

By calculating the comprehensive average value and the range difference, the order of influence of each factor on the medium / long-chain fat emulsion emulsification process is the homogenization pressure →pH value → homogenization temperature. The experimental results show that the main factor affecting the emulsification process is the homogenization pressure, followed by the pH value and the homogenization temperature. Under the experimental conditions, the combination of Zui excellent level is: homogenization pressure 21 MPa , pH value 8.0 , homogenization temperature 60 °C .

　　 3 preparation process

According to the results of the above emulsification process optimization experiment, the preparation process of the medium / long chain fat emulsion injection is as follows: the prescribed amount of soybean oil and medium chain triglyceride are weighed in a liquid mixing pot, uniformly mixed by a high speed masher, and heated. At 80 ° C , lecithin was added and chopped at high speed until completely dissolved to make a homogeneous clear solution. Another amount of water for injection is added to the glycerin, placed in another liquid mixing pot, stirred and mixed under nitrogen protection, and heated to 60 °C . The phospholipid oil solution was slowly added to the aqueous glycerin solution under high-speed agitation, and the pH was adjusted to about 8.0 with sodium hydroxide . It was repeatedly homogenized by a high-pressure homogenizer until the particles were around 0.33 μm , filtered with a 1 μm microporous membrane, filled in an infusion bottle, filled with nitrogen, butyl rubber stopper, and sealed with an aluminum cap. 115 ℃ rotation sterilized 25 min, i.e., too.

　 　 4 verification of the preparation process

Three batches of samples were prepared by the above-mentioned optimized horizontal combination preparation process , and were tested according to the quality standard of medium / long chain fat emulsion injection, and the indexes met the requirements. Take the above three batches of samples and observe them at 25 °C for 18 months. Except for a slight decrease in pH value, the other indicators have no obvious changes, which meet the requirements of quality standards . See Table 3 for the observation data .
　　
Table 3 18 months of observation at 25 °C (slightly)

　　 5 other measures to ensure product quality

A good quality fat emulsion requires a suitable particle size, uniform distribution, stable shelf life and good clinical tolerance. In order to meet the above requirements, in addition to strict control of the process conditions mentioned in the optimization experiment, the source and quality control of the raw materials should be controlled, the oxidation prevention process measures, the sterilization temperature and mode selection, and during preparation and storage. Temperature control and other aspects have been given full attention and related measures have been put in place. According to the current process conditions, the temperature of the homogenization process should be controlled at (60 ± 1) °C , the pH value is between 7.5 and 8.5 , and the entire preparation process should be carried out under nitrogen protection conditions. In order to ensure that the formed emulsion in the sterilization process is not damaged, it is necessary to ensure uniform heating of the entire process vessel, and thus it is necessary to use a rotary sterilization method. At the same time, the storage of the product should be placed in a cool place below 25 °C , and stored in the dark.

　 　 6 discussion

　　 61 fat emulsion is an O/W emulsion, which is a heterogeneous dispersion system composed of two mutually incompatible liquid phases, which is an unstable system in kinetic classification [4]. Medium / long-chain fat emulsion injection due to formulation contained 5% MCT, MCT is a saturated fatty acid having 6 to 12 carbon atoms, whose molecular weight less than LCT, while water-soluble, but about 100 times higher than LCT. From the principle of O/W emulsion formation, under the conditions determined by the emulsifier, the longer the hydrocarbon chain of the oil, the stronger the lipophilicity of the oil phase, and the better the stability of the emulsion. On the contrary, the stability is relatively poor. Compared with long-chain fat emulsion, the medium / long-chain fat emulsion injection has a relatively lower lipophilicity of the oil phase in the whole system due to the addition of MCT , and it is easy to appear oil slick in the homogenization process, and the uneven distribution of the milk particles increases. Preparation difficulty. Medium / long-chain fat emulsion injection preparation process, the equipment used is roughly the same as long-chain fat emulsion, but the specific process conditions / long-chain fat emulsion injection is more strict, mainly in homogenization pressure, homogenization temperature, pH control, sterilization temperature and time. The results of pharmaceutical research show that the quality of the medium / long-chain fat emulsion injection prepared by the above process is controllable, and the product in the storage period is stable. Clinical studies have shown that its clinical application is safe and its effectiveness is similar to imported licensed medium / long-chain fat emulsion injections.

　　 62 To prepare a stable and clinically tolerated fat emulsion injection, in addition to strict preparation process and controllable quality standards, the choice of raw materials is very important, which is a prerequisite for the development and production of fat emulsions. It is related to clinical medication safety. The medium / long-chain fat emulsion injection is a biochemical drug, and the soybean oil, MCT , and lecithin used are extracted from relevant parts of plants or animals, and are obtained by physical or chemical methods. Different origins and different extraction processes may cause changes in the composition of raw materials, and even cause changes in physical and chemical constants, affecting the emulsification effect. More serious is the possibility of introducing impurities from the raw materials that cannot be controlled by quality standards. The impact of these trace impurities on the safety of clinical drugs has attracted the attention of foreign clinical nutritionists. Adverse reactions such as fever and abnormal liver function in the clinical use of fat emulsion are caused by trace impurities introduced from raw materials. The effects of large dose and long-term use are more serious, and the toxic side effects are even irreversible. of. Subacute trials of dogs reported abroad have found that different fat emulsions can cause different organ damage, even before the end of the trial [6]. In order to investigate the safety of the developed products, the subacute toxicity test of Beagle dogs was carried out according to the widely accepted experimental design scheme. We used medium and long-chain fat emulsions prepared by the same preparation process of soybean oil, MCT and lecithin from different manufacturers. According to the dose of 9 g / kg ? d-1 ( human 10 times dose ) for 28 days , the subacute response of the dog and its effect on its target organs were observed. The results showed that the effects of soybean oil and lecithin from different manufacturers on dog liver were very different, and severe cases could cause irreversible hepatic necrosis. The animal test results suggest that the raw and auxiliary materials required for the production of fat emulsion should be controlled in accordance with the corresponding quality standards, and the subacute test of the dog should be carried out at the same time, and the raw material manufacturers should be determined according to the experimental results. Through this effective measure, we ensure the safety of clinical medication.

However, fat emulsion injection is more difficult to prepare, and the main problem is that physical stability and heat source are not easy to meet the requirements. Main

Fat emulsions are an important part of parenteral nutrition and are energy supplements. Clinically, in addition to providing the energy required for metabolism, the fat emulsion also provides the body with polyunsaturated fatty acids required for the metabolism of biofilms and biologically active substances, preventing and correcting the lack of essential fatty acids in the body. At present, the fat emulsion commonly used in clinical practice is a long-chain triglyceride (LCT) fat emulsion. The basic prescription is based on soybean oil (LCT) , using refined lecithin as an emulsifier and glycerol as an isotonic agent. High pressure homogenization. Many years of clinical application studies have found that high-dose or long-term continuous use of long-chain fat emulsions can cause hyperlipidemia, damage to the immune system and affect the function of important organs such as the reticuloendothelial system and liver [1]. Germany B.Braun company on the basis of long-chain fatty emulsion in-depth research, in the mid-1980s created a new generation of fat emulsion - medium / long-chain fat emulsion injection (Lipofundin MCT / LCT). The medium / long-chain fat emulsion injection uses the body's more easily absorbed medium chain triglyceride (MCT) as an energy source while retaining part of the LCT as a source of essential fatty acids. The group fully utilized the characteristics of MCT in the body, such as easy hydrolysis, rapid oxidation and simple metabolic process, which made up for the deficiency of LCT fat emulsion. Compared to LCT fat emulsions, medium / long-chain fat emulsions provide faster energy, better protein synthesis, good liver tolerance and nutritional effects that maintain normal immune function. In foreign countries, medium / long-chain fat emulsion injections have been commonly used for clinical nutritional support. The product entered the Chinese market in 1991 , and its exact clinical nutritional effects have been confirmed by domestic clinical application research and listed as a national medical insurance class A drug. In order to speed up the development of China's intravenous nutrition business and support domestic varicose nutrition varieties, we have successfully developed medium / long chain fat emulsion injection. The research content of the preparation process will now be reported as follows.

　　 1 prescription

　　 11 10% / long chain fat emulsion injection injectable formulation consisting of soybean oil 50 g, injection medium chain triglycerides 50 g, injectable lecithin 12 g, glycerol injection 25 g, water for injection was added to 1000 mL .

　　 1.1 The prescription is based on the prescription of the foreign import license medium / long-chain fat emulsion injection.

　　 1.2 The role of each component in the prescription Soybean oil and medium chain triglycerides are the main components, lecithin is an emulsifier, and glycerol is an isotonic regulator.

　 　 2 emulsification process optimization experiment

The optimization experiment scheme of the emulsification process is based on the preparation process of the long-chain fat emulsion injection, combined with the characteristics of the medium / long-chain fat emulsion injection, and the orthogonally tested method is used to select the most influential process conditions to determine the applicable. Preparation process.

　　 2.1 Experimental material and instruments injectable medium chain triglycerides (CONDEA Company, Germany), soybean oil for injection (Germany LiPoid Corporation), lecithin for injection (Germany LiPoid Corporation), glycerin for injection (Shan Ning amino acids Ltd.). Experimental high pressure homogenizer, Coulter particle analyzer, acidity meter, experimental glass instrument set.

　　 2.2 Experimental method The core technology of the preparation process of fat emulsion is the emulsification process. According to the experience of developing and producing long-chain fat emulsion injection and the characteristics of each component in medium / long-chain fat emulsion injection, various factors that may have a great influence on the particle size and distribution of the milk during the preparation process are listed. And level , select the L9 (34) orthogonal table [2] design experiment. Using the distribution of the milk particles as a judgment index, the distribution of the experimental emulsion particles in each group was measured by a Coulter particle analyzer. The data processing is based on the percentage of particles above 1 μm and the percentage of particles above 0.5 μm as the index [3]. The small value indicates that the large particles are small and the milk particles are evenly distributed ( see Table 1 for the level of each factor ) .

Table 1 factor level table (omitted)

　　 2.3 The experimental results are shown in Table 2 .

Table 2 L9 (34) test plan and experimental results table (omitted)

By calculating the comprehensive average value and the range difference, the order of influence of each factor on the medium / long-chain fat emulsion emulsification process is the homogenization pressure →pH value → homogenization temperature. The experimental results show that the main factor affecting the emulsification process is the homogenization pressure, followed by the pH value and the homogenization temperature. Under the experimental conditions, the combination of Zui excellent level is: homogenization pressure 21 MPa , pH value 8.0 , homogenization temperature 60 °C .

　　 3 preparation process

According to the results of the above emulsification process optimization experiment, the preparation process of the medium / long chain fat emulsion injection is as follows: the prescribed amount of soybean oil and medium chain triglyceride are weighed in a liquid mixing pot, uniformly mixed by a high speed masher, and heated. At 80 ° C , lecithin was added and chopped at high speed until completely dissolved to make a homogeneous clear solution. Another amount of water for injection is added to the glycerin, placed in another liquid mixing pot, stirred and mixed under nitrogen protection, and heated to 60 °C . The phospholipid oil solution was slowly added to the aqueous glycerin solution under high-speed agitation, and the pH was adjusted to about 8.0 with sodium hydroxide . It was repeatedly homogenized by a high-pressure homogenizer until the particles were around 0.33 μm , filtered with a 1 μm microporous membrane, filled in an infusion bottle, filled with nitrogen, butyl rubber stopper, and sealed with an aluminum cap. 115 ℃ rotation sterilized 25 min, i.e., too.

　 　 4 verification of the preparation process

Three batches of samples were prepared by the above-mentioned optimized horizontal combination preparation process , and were tested according to the quality standard of medium / long chain fat emulsion injection, and the indexes met the requirements. Take the above three batches of samples and observe them at 25 °C for 18 months. Except for a slight decrease in pH value, the other indicators have no obvious changes, which meet the requirements of quality standards . See Table 3 for the observation data .
　　
Table 3 18 months of observation at 25 °C (slightly)

　　 5 other measures to ensure product quality

A good quality fat emulsion requires a suitable particle size, uniform distribution, stable shelf life and good clinical tolerance. In order to meet the above requirements, in addition to strict control of the process conditions mentioned in the optimization experiment, the source and quality control of the raw materials should be controlled, the oxidation prevention process measures, the sterilization temperature and mode selection, and during preparation and storage. Temperature control and other aspects have been given full attention and related measures have been put in place. According to the current process conditions, the temperature of the homogenization process should be controlled at (60 ± 1) °C , the pH value is between 7.5 and 8.5 , and the entire preparation process should be carried out under nitrogen protection conditions. In order to ensure that the formed emulsion in the sterilization process is not damaged, it is necessary to ensure uniform heating of the entire process vessel, and thus it is necessary to use a rotary sterilization method. At the same time, the storage of the product should be placed in a cool place below 25 °C , and stored in the dark.

　 　 6 discussion

　　 61 fat emulsion is an O/W emulsion, which is a heterogeneous dispersion system composed of two mutually incompatible liquid phases, which is an unstable system in kinetic classification [4]. Medium / long-chain fat emulsion injection due to formulation contained 5% MCT, MCT is a saturated fatty acid having 6 to 12 carbon atoms, whose molecular weight less than LCT, while water-soluble, but about 100 times higher than LCT. From the principle of O/W emulsion formation, under the conditions determined by the emulsifier, the longer the hydrocarbon chain of the oil, the stronger the lipophilicity of the oil phase, and the better the stability of the emulsion. On the contrary, the stability is relatively poor. Compared with long-chain fat emulsion, the medium / long-chain fat emulsion injection has a relatively lower lipophilicity of the oil phase in the whole system due to the addition of MCT , and it is easy to appear oil slick in the homogenization process, and the uneven distribution of the milk particles increases. Preparation difficulty. Medium / long-chain fat emulsion injection preparation process, the equipment used is roughly the same as long-chain fat emulsion, but the specific process conditions / long-chain fat emulsion injection is more strict, mainly in homogenization pressure, homogenization temperature, pH control, sterilization temperature and time. The results of pharmaceutical research show that the quality of the medium / long-chain fat emulsion injection prepared by the above process is controllable, and the product in the storage period is stable. Clinical studies have shown that its clinical application is safe and its effectiveness is similar to imported licensed medium / long-chain fat emulsion injections.

　　 62 To prepare a stable and clinically tolerated fat emulsion injection, in addition to strict preparation process and controllable quality standards, the choice of raw materials is very important, which is a prerequisite for the development and production of fat emulsions. It is related to clinical medication safety. The medium / long-chain fat emulsion injection is a biochemical drug, and the soybean oil, MCT , and lecithin used are extracted from relevant parts of plants or animals, and are obtained by physical or chemical methods. Different origins and different extraction processes may cause changes in the composition of raw materials, and even cause changes in physical and chemical constants, affecting the emulsification effect. More serious is the possibility of introducing impurities from the raw materials that cannot be controlled by quality standards. The impact of these trace impurities on the safety of clinical drugs has attracted the attention of foreign clinical nutritionists. Adverse reactions such as fever and abnormal liver function in the clinical use of fat emulsion are caused by trace impurities introduced from raw materials. The effects of large dose and long-term use are more serious, and the toxic side effects are even irreversible. of. Subacute trials of dogs reported abroad have found that different fat emulsions can cause different organ damage, even before the end of the trial [6]. In order to investigate the safety of the developed products, the subacute toxicity test of Beagle dogs was carried out according to the widely accepted experimental design scheme. We used medium and long-chain fat emulsions prepared by the same preparation process of soybean oil, MCT and lecithin from different manufacturers. According to the dose of 9 g / kg ? d-1 ( human 10 times dose ) for 28 days , the subacute response of the dog and its effect on its target organs were observed. The results showed that the effects of soybean oil and lecithin from different manufacturers on dog liver were very different, and severe cases could cause irreversible hepatic necrosis. The animal test results suggest that the raw and auxiliary materials required for the production of fat emulsion should be controlled in accordance with the corresponding quality standards, and the subacute test of the dog should be carried out at the same time, and the raw material manufacturers should be determined according to the experimental results. Through this effective measure, we ensure the safety of clinical medication.

However, fat emulsion injection is more difficult to prepare, and the main problem is that physical stability and heat source are not easy to meet the requirements. The main factor is the quality of the phospholipid used, which is one of the key to the production of fat emulsion; secondly, the preparation process conditions are difficult to control, and the equipment such as the milk homogenizer needs to be further improved. The school has made great progress in the research of fat emulsions, and can produce qualified products with domestic excipients.

The factor is the quality of the phospholipid used, which is one of the keys to the production of fat emulsions; secondly, the preparation process conditions are difficult to control, and the equipment such as the milk homogenizer needs to be further improved. The school has made great progress in the research of fat emulsions, and can produce qualified products with domestic excipients.