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Premixed insulin

Premixed insulin

Premixed insulin


  • Mixed Protamine Human Insulin Injection (30R)
  • 100 units/mL, 3 mL (penfill)
  • Human insulin
  • White or off-white suspension
  • Diabetes

Similin®30 is a premixed insulin used to treat adults with type 1 and type 2 diabetes for the control of high blood sugar. Before using Similin®30 for the treatment of diabetes, please read the instruction leaflet and follow your doctor’s advice.

Product FAQs

The information below is solely for the purpose of addressing your inquiry and should not be used for promotional or advertising purposes. It is not intended to serve as a clinical medication guidance.

※ Injection and Use

● When is the best time to inject Similin®30? Before or after a meal?

With Similin®30, it is essential to take the injection before a meal. In addition, a carbohydrate-containing meal must be taken within 30 minutes of the injection, or an additional meal if necessary.

● Can Simillin®30 (cartridge) be used in an insulin pump?

Simillin®30 (cartridge) cannot be used in insulin pumps.

● What is the best place to administer insulin? Is it necessary to rotate injection sites regularly?

Typical injection sites encompass the abdomen, upper and outer arms, front and outer thighs, as well as buttocks. Among these, the abdomen is generally preferred.

To maintain optimal results, it's recommended to rotate the subcutaneous injection site regularly. It's advisable to avoid using the same location for insulin injections within a two-week period. This practice prevents a decrease in the ability of the subcutaneous tissue to absorb insulin due to multiple injections in a concentrated area over a short period of time.

Such repeated injections in the same area can lead to problems such as fat nodules, which can affect the absorption and use of insulin.

● What happens if you notice symptoms such as redness, itching, rash, or swelling at the injection site?

Pouching: If the injection is mistakenly placed on the surface of the skin (dermis 1.8 mm-2.5 mm) rather than in the subcutaneous fat layer, pouching will occur.

Pain, redness, and swelling: If the injection reaches the muscle layer and the fat at the injection site is thin, you may experience pain, redness or swelling. To avoid this, consider changing the injection site or using a different type of needle next time. It's important to note that pinching the skin during the injection can help to ensure that the injection is properly angled.

Local allergic reactions: Symptoms such as redness, itching, rash and swelling at the injection site are usually mild and local allergic reactions. These reactions are usually temporary and will gradually subside as treatment continues. If these symptoms persist or worsen, it's advisable to consult a healthcare professional immediately for appropriate advice.


● What causes ecchymosis when insulin is injected subcutaneously?

The emergence of this condition is not linked to the insulin medication itself. Potential triggers encompass repeated use of disposable needles, microvascular disease, brittle blood vessels, abnormal coagulation function, etc.; the human skin is divided into epidermis and dermis, and there are blood vessels in the dermis layer, which may also lead to rupture of blood vessels and formation of ecchymosis when injected in an improper manner.

Scientific studies have shown that finer needles correlate with a reduced incidence of discomfort and ecchymosis. Patients are therefore advised to switch to finer needles and establish a consistent injection technique. In cases of severe ecchymosis, patients are advised to seek immediate medical advice to determine the possible presence of underlying medical factors.

● What causes medication to leak from the injection site after administration?

Insufficient absorption and leakage of the medication may occur if the needle is withdrawn from the skin too quickly after a short time. To improve absorption and prevent leakage, it's advisable to keep the needle under the skin for more than 10 seconds.

Prolonged injection at the same site can lead to fat hyperplasia and the development of solid nodules, which may also lead to needle leakage. To mitigate these problems, it is advisable to consistently rotate the injection site for insulin administration. This practice will effectively prevent the above situations from occurring.

● After switching from abdominal to arm injections due to prolonged abdominal fat hyperplasia, the patient experienced an increase in fasting blood glucose of 1.5 mmol/L compared to her previous levels. This change in glucose levels could potentially be attributed to what underlying cause?

Typically, the fat layer in the arm is thinner than in the abdomen, which makes it easier for arm injections to reach the muscle layer. When injected into the muscle layer of the arm, there are distinct characteristics of insulin absorption that are different from those seen when injected into the subcutaneous fat layer. These include a rapid rise in insulin levels, earlier peak concentrations, and a shorter duration of insulin action. This may result in an inadequate duration of action and an increase in fasting blood glucose levels. If this situation occurs and the patient wishes to continue with arm injections, it is advisable to consider switching to a shorter needle or using a pinch technique to ensure that insulin doesn't infiltrate the muscle layer. Choosing to inject into the buttock can also reduce the risk of injecting into the muscle layer. 

If the above strategies fail to reduce blood glucose levels, it is plausible that the patient's condition has progressed, possibly involving escalated beta cell damage or increased insulin resistance. In such cases, it is recommended that the patient seek immediate medical attention by visiting a hospital and consulting with a healthcare professional.

● What is the purpose of the tiny glass bead-like spheres within Similin®30 (cartridge)?

These tiny glass beads are intentionally placed within the cassette bottle of Similin®30  to aid in effectively mixing the medication. Refer to the Similin®30 instructions for further details.


● Why is it important to shake Similin®30 well before use?

Proper shaking of Similin®30 prior to use is essential to achieve a consistent insulin concentration within the suspension. This will ensure that the insulin concentration is the same for each injection. Inadequate mixing prior to injection may result in reduced insulin effectiveness and fluctuations in blood glucose levels. Shake the insulin as follows: Place the pre-mixed insulin horizontally on the palm of your hand, gently roll it back and forth to the count of 10, then turn it upside down and repeat the process 10 times. Use the solution when it has turned a uniform milky white color (ensure a sufficient number of shakes as occasional shaking may not achieve the desired uniformity). Avoid vigorous shaking as this may affect the structure and effectiveness of the insulin, ultimately affecting its ability to lower blood glucose levels).

※ Storage and Stability

● Can insulin be injected right after taking it out of the fridge?

No. Insulin needs to be taken out of the refrigerator and left at room temperature for a while, and then injected when it returns to room temperature. Immediate injection after taking insulin out of the fridge may result in a delayed onset of action due to the effect of cold temperatures on protein activity. This delay could potentially affect blood glucose control. In addition, cryogenic injection can cause increased discomfort for the patient.

● Can insulin still be used if it's accidentally frozen, and why?

It is not possible to use insulin that has been frozen.

This is because insulin is a protein-based drug and freezing can cause denaturation of the protein, altering its activity and affecting its effectiveness in lowering glucose levels and potentially compromising safety. The optimum storage temperature for insulin is between 2°C and 8°C.

● Can insulin be taken onto an airplane or be part of a check-in?

Travelers with diabetes can carry sufficient supplies of insulin, as well as hypodermic syringes and needles, with a medical certificate. When traveling by air, insulin should be carried as hand luggage and not placed in checked baggage. This is because the temperature in the baggage compartment can often drop below 0°C and the extreme cold can make insulin ineffective.

Medicines and injections should be packed securely, with labels retained as proof of authenticity. Insulin should be separated from other carry-on items for security screening and presented to security personnel for inspection. Unopened insulin should be stored in a refrigerator between 2°C and 8°C. Occasionally, airport security may not allow small ice packs to be carried. In such cases, discussions with security management may lead to permission for 1~2 small ice packs. Alternatively, requesting ice from flight attendants after boarding can serve the same purpose.

● Can medicines that expire in a month still be used?

Yes. Medicines are safe to use as long as they are within their shelf life, and do not use them after their shelf life has expired.

● In cases where patients require a lower dose of insulin, how should patients address the situation if a medication is not fully utilized within a 28-day period?

A medicine should be used within 28 days of opening, and a new insulin cartridge should be replaced if it has not been used up for more than 28 days.

※ Quality and Safety


● Can I use an insulin cartridge that has small air bubbles in it?

When insulins are filled, it is inevitable that a small amount of air will enter the product, causing small bubbles to form. These cartridges are rigorously tested at the factory before distribution. The presence of air bubbles in unopened cartridges doesn't affect the quality of the medicine or the accuracy of the dose. However, it's important to remove the air properly before injecting. 

Administer insulin injections correctly and be sure to remove the needle after each use. This will prevent the introduction of air, which can reduce the effectiveness of the medication.

● What if foreign bodies or red, brown, or white flocs appear in the liquid medicine during use?

Based on our company's previous blood return tests, the introduction of blood into the product results in the formation of foreign particles such as flakes, granules, and fibers. In addition, the color of the liquid may either remain a light yellow or show no significant change due to the presence of blood in the return. (Since 2019, Gan & Lee has received a total of 11 complaints related to blood return incidents. We have also observed similar complaints related to foreign bodies in 2019, 2020, and 2021. All of these cases were confirmed to be related to blood-return events. Possible factors contributing to the occurrence of foreign bodies in blood return incidents may include repeated needle use or improper handling during insulin administration. To mitigate these problems, we advise patients to use new disposable needles for each insulin injection, to remove needles from the product immediately after use, to follow the injection site recommendations in the instructions, and to observe the storage conditions specified in the instructions after use). If red flocculent material is visible, this may indicate a small amount of blood from the syringe returning to the vial. White particles are usually caused by the cartridge stopper, which can release rubber particles into the cartridge as a result of repeated needle punctures. In such cases, it is advisable to stop using that particular insulin cartridge.

● Does Similin®30 exhibit a lower quality and efficacy compared to imported originator products?

In terms of product quality, Gan & Lee uses production equipment imported from Germany and integrates molecular chaperone technology into its manufacturing process to ensure the protein purity of the product. Gan & Lee's quality control criteria are aligned with the European and American Pharmacopoeias, with even more stringent requirements for "residual DNA" and "microbial limit" compared to the standards of the European and American Pharmacopoeias. The substantial 24-month shelf life of Similin®30 is a robust indicator of the product's stability.

In terms of product efficacy, it has been clinically proved that there is no difference in clinical efficacy and safety between Similin®30 and the original drug.

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