We have a product that has 4 ingredients API, two excipients and water. API 30%, excipients 15% and 10% disolved in water.I want to use TOC method All three ingredients have OC. I want to construct a standard curve of known amounts ( 10 PPM to 0.1 PPM) and read the final rinse sample against it.

My question is how should I dilute the product to achieve this concentration using finished product.

Can calculation be done from a single curve for each ingredient.

We have a product that has 4 ingredients API, two excipients and water. API 30%, excipients 15% and 10% disolved in water.I want to use TOC method All three ingredients have OC. I wa sample against it. nt to construct a standard curve of known amounts ( 10 PPM to 0.1 PPM) and read the final rinse

My question is how should I dilute the product to achieve this concentration using finished product.

Can calculation be done from a single curve for each ingredient.

Best Regards[/quote]

Hi gokeeffe,

First, you should know that TOC method is non specific one so you cannot differentiate between th API and the other 2 excipients as long as they all contain organic carbon.

second. so what you will get is the estimate of the total amount of the API and the other 2 excpients in the final rinse sample without knowing the exact amount of each one.

Third. you can construct the standard curve easily by knowing the amount of each ingredient in the product, chemical formula, the amount of water you dilute in and the TOC value of the purified water you dilute the product in.

IF you need the exact calculations just let me know…
Hope this helps, regards.

shady abdelraouf
Head of Microbiology department, Eur.Egy.company for pharm. ind.