Insulin types and differences

Many people are actually not very clear that there are many types of insulin, and there are also many differences between different types. It is necessary to choose the most suitable insulin for injection according to your symptoms. Only in this way can it be considered as the right medicine for the disease. Otherwise, it is just using drugs indiscriminately. So which type of insulin is better to use? This still needs to be judged according to the doctor's advice.

This product is white or off-white crystalline powder.

This product is almost insoluble in water and ethanol; it is easily soluble in inorganic acid or sodium hydroxide solution.

Identification

(1) In the chromatogram recorded under the assay, the retention time of the major peak of the test solution should be consistent with the retention time of the major peak of the reference solution.

(2) Take an appropriate amount of this product and use 0.1% trifluoroacetic acid solution to prepare a solution containing 10 mg per 1 ml. Take 20 μl and add 20 μl of 0.2 mol/L tris(hydroxymethyl)aminomethane-hydrochloric acid buffer (pH 7.3), 20 μl of 0.1% V8 enzyme solution and 140 μl of water. Mix well and place in a 37°C water bath for 2 hours. Then, add 3 μl of phosphoric acid to prepare the test solution. Take an appropriate amount of insulin reference substance and prepare it in the same way to prepare the reference solution.

According to the chromatographic conditions under the content determination item, 0.2 mol/L sulfate buffer (pH 2.3)-acetonitrile (90:10) was used as mobile phase A, acetonitrile-water (50:50) was used as mobile phase B, and gradient elution was performed as shown in the table below. Take 25 μl of the reference solution and the test solution, inject them into the liquid chromatograph respectively, and record the chromatogram. The peptide spectrum of the test solution should be the same as that of the reference solution.

Loss on drying

Take about 0.2g of this product, weigh accurately, and dry at 105℃ to constant weight. The weight loss shall not exceed 10.0% (Appendix VIIIL, Part II, 2010 Pharmacopoeia).

Zinc

Take an appropriate amount of this product, weigh it accurately, add 0.01 mol/L hydrochloric acid solution to dissolve it and quantitatively dilute it to make a solution containing about 0.1 mg per 1 ml as the test solution. Separately, accurately measure an appropriate amount of zinc single element standard solution (containing 1000 μg zinc per 1 ml) and quantitatively dilute it with 0.01 mol/L hydrochloric acid solution to prepare zinc standard solutions containing 0.20 μg, 0.40 μg, 0.80 μg, 1.00 μg and 1.20 μg zinc per 1 ml. The absorbance was measured at a wavelength of 213.9 nm by atomic absorption spectrophotometry (Appendix IV D Method 1 of Part II of the Pharmacopoeia 2010). Calculated on a dry basis, the zinc content shall not exceed 1.0%.

Bacterial endotoxins

Take this product, add 0.01 mol/L hydrochloric acid solution to dissolve and dilute to make a solution containing 5 mg per 1 ml. According to the legal inspection (Appendix ⅪE of Part II of the 2010 edition of the Pharmacopoeia), the amount of endotoxin in each 1 mg of insulin should be less than 10EU.

Microbial Limits

Take 0.2g of this product and check it according to the law (Appendix Ⅺ J of Part II of the 2010 Edition of the Pharmacopoeia). The number of bacteria in each 1g shall not exceed 300 cfu.