Can Insuman Basal Solostar be converted to Insulatard penfill?

Both preparations - Insuman Basal Solostar and Insulatard penfill are drugs containing human isophane insulin and in both cases in 1 ml there is 100 IU. However, these are not exactly their substitutes, because human insulin in each of them is obtained slightly differently. Changing insulin to another type or brand should be done under close medical supervision. A change in potency, brand (manufacturer - as in this case), type (ordinary, NPH, lente, long-acting, etc.), origin (human, animal, analogue of human insulin), as well as the method of manufacture (as in this case) may cause the need to change the dose. Therefore, there is no reason to safely replace Insuman with Insulatard. The change in insulin must also take into account the time of the final action of the previous preparation ("tail", which for several hours "pulls" after administration - especially basal insulin) and the beginning ("unwinding" of action) of the new base insulin. With such a change, the patient must receive specific instructions on the dosage of the drug. Besides, if you are currently using insulin in the form of pre-charged pens (Solostar), and you would need to change to insulin in cartridges (penfill), then you need a dedicated pen for insulin of a given company. Not in every pharmacy such pens are available, so to get it you would have to contact the clinic. You should also be trained in the use of new equipment. In the case of switching to Insulatard, but in factory-charged pens - it would have to be Insulatard FlexPen, but I do not see that it is available in pharmacies integrated with GdziePoLek. In my opinion, an easier and safer replacement option is to change the form in which the same insulin is available (Solostar -> cartridges). What do I mean? In fact, you can see less availability of Insuman Basal Solostar: https://www.gdziepolek.pl/produkty/37929/insuman-basal-solostar-iniekcja/apteki/w-polsce but slightly better available is Insuman Basal: https://www.gdziepolek.pl/produkty/37926/insuman-basal-iniekcja/apteki#stacjonarne It is the same insulin, only available in cartridges, not ready-made pens. If there are reusable pens available in the pharmacy or you have contact with the clinic to ask about the availability of pens for this insulin - this will be a sure solution to this situation without having to change the insulin (change the substance). In another case - it is necessary to contact a doctor. I leave a link to the video in which I show what reusable pens look like and how they are used: