What is Pharmaceutical Polypeptide?

With the rapid development of biotechnology, peptides and protein drugs are emerging. At present, there are 35 kinds of important therapeutic drugs on the market, and the development of biotechnology and Biopharmaceutical Enterprises is increasingly globalized. The focus of biotechnological drug research is to develop clinical polypeptides, proteins, enzymes, hormones, vaccines, growth factors and monoclonal antibodies using DNA recombination technology. According to Parexl's Pharmaceutical R&D Statistical Source Book, 723 biotechnological drugs are currently under FDA review (including phase I-III clinical and FDA evaluation), 700 drugs are in the early stage of research (research and pre-clinical), and more than 200 drugs have entered the final approval stage (phase III clinical and FDA evaluation). . The basic form of biotechnological drugs is lyophilized. Although the curative effect of routine preparations has been proved by clinic for a long time, they need to be injected frequently for a long time due to their short half-life. These are unacceptable problems from the perspective of patients'psychological and economic burden. For this reason, scholars from all over the world have mainly started to research and develop convenient and reasonable ways of administration and new preparations from two aspects: implants and sustained-release injections. (2) non injectable type, such as inhalation of respiratory tract, rectal administration, nasal cavity, oral administration and transdermal administration. Sustained-release injections of biotechnological drugs are promising new dosage forms. Some kinds of microsphere injections which can sustain the release of luteinizing hormone-releasing hormone (LHRH) analogues for 1 to 3 months have been put on the market. This article mainly introduces these preparations. 1. The main types of polypeptide and protein drug sustained-release preparations are polypeptide and protein drug sustained-release preparations. In terms of development process and formulation, they are mainly divided into implant and microsphere injection. 1.1 implant 1.1.1 fine rod implant is a hollow micro-rod with one end closed and the other opening. The rod is a non-biodegradable polymer such as polytetrafluoroethylene. A mixture of drugs and silica gel (silastic, poly two methyl siloxane) was injected into the cavity. The implant is embedded in the skin of human body, and the drug is released slowly through the opening of silica gel matrix. The American Physician's Handbook (PDR) contains an implant called Norplant? For levonorgestrel, which is used in family planning. The preparation is 2.4 mm in diameter and 34 mm in length. Doctors implant six fine rods in the medial arm of the patient through surgery. The drug can be released in a zero-order mode in vivo for 5 years. After drug release, it can be removed by surgery. 1.1.2 Microosmotic pump implant Alza Company developed a capsule-like implant in the 1970s. The implant is embedded under the skin or in other parts. The body fluid can penetrate through the shell, dissolve the electrolytic layer of the interlayer, make the expanded interlayer press into the plastic inner cavity, and promote the drug solution to release at a constant rate from the opening. Many biological macromolecular drugs, such as insulin, heparin and nerve growth factor, have been reported as model drugs in vivo and in vitro. Implant has positive significance for the treatment of chronic patients who need long-term medication, but it has the following shortcomings: 1. It must be implanted through surgical approach. 2. The skeleton material of the preparation is a non biodegradable polymer. After the release of the drug, it needs to be removed by surgery. 3. Preparations have irritation and discomfort in local tissues. Evaluation methods of polypeptide protein drugs: 1, liquid chromatography 2, spectroscopy 3, electrophoresis 4, bioassay and immunoassay, general prescription composition of polypeptide protein drugs: currently used in clinic, one is solvent-based injection, the other is freeze-dried powder injection. Solvent type is easy to use, but it needs to be kept at low temperature (2-8 degrees Celsius).