what does 407 means in Poloxmer 407. Why it is used with it ?
Poloxamers come in various sizes and differ in exact chemical make up so there is typically a 3 digit number following the word to aid in identification. The first two numbers (in this case 40) represent the molecular mass of the polyoxypropylene core divided by 100. So poloxamer 407 has a polyoxypropylene core with a molar mass of of 40 x 100 = 4,000 g/mol. Then the final number (in this case 7) represents the percentage polyoxyethylene content divided by 10. So poloxamer 407 is 7 x 10 = 70% polyoxyethylene
