Screening And Stability Study Of Freeze-drying Formula For Recombinant Human Growth Hormone

Human growth hormone (high) is a protein excreted by anteriorpituitary, is a kind of peptide hormones. Growth Hormone produced throughthe DNA recombination technology called recombinant human growth hormone(rhGH), its structure and structure of growth hormone (high) is the same.It is proved that recombinant human growth hormone (rhGH) and peoplegrowth hormone (high) have the same physiological function by clinicaltests.Main physiological function of Growth Hormone is to promote allorganizations growing except the neural tissue, metabolism of thesynthesis and synthesis of protein, decomposing of adipose; GrowthHormone is insulin’s antagonist, it restrain decomposing of glucose,make blood sugar increase.In young children Growth Hormone secretingdeficiency can lead to slow growth, small disease, secreting redundantlycan lead to acromegaly and other diseases.Growth hormone is not stable in the process of storage, especiallyin liquid conditions, it is oxidation, take off amine, polymerizationreaction easily, make growth hormone’s purity decline, biologicalactivity is affected, so as to reduce the quality of the products, so itis very necessary developing a kind of the preparations formula thatmaintain growth hormone to the stability.Confirming of Oxidation products and eamination product: through thereaction experiment accelerated, with GH-RP HPLC method to confirmretention time of oxide product and eamination products in thechromatogram.Confirming buffer solution and pH value: the buffer system and pHvalue have an effect on the stability of rhGH. Five different kinds of buffer solution is selected in the test,they are Tris-HCl, Malayacid,Citric acid-anhydrous sodium citrate, PB, L-Histidine and pH6.0.Mix rhGH solution, ensure each sample contains10mM buffer solution and1mg/ml rhGH, test related projects of sample after acceleration test,through analysis the test data,and comparison,obtain a result: rhGHis more stable in10mM PB buffer system. Screening experiments of pHvalue show that rhGH has good stability in PB (pH6.5) conditions.Sugar, polyols affect lyophilized dosage of protein on stability andappearance,are the main influence factors of protein, testing resultaccording to the mannitol, sucrose, trehalose, combined ratio, found that3%of mannitol,2%of trehalose formula is better.Amino acids can maintain the stable of pH value of complex solutionand lyophilized dosage form well. According to screening experiment ofthe glycine and arginine, Found that2%of glycine better than arginine.Surface active agent can restrain polymerization of protein well, andscreening Tween-20, Tween-80， Poloxamer188in the experimental process,found that0.01%Poloxamer188is capable of restraining lyophilizationof rhGH in lyophilized dosage form.Final,rhGH lyophilized dosage form formula contain5mM PB,1.0mg/mlrhGH,3%mannitol,2%trehalose,2%glycine,0.01%Poloxamer188.According to the formula,product freeze-dried sample to rhGH, in2-8℃conditions storage, according to the design of the time test relatedproteins, polymer protein, activity, moisture, and so on.The results showthat the lyophilized dosage can be saved steadily for2years or abovein2-8℃conditions.