Why would you want to go this way when other simpler and straight-forward methods are available?! 

See the following:

Dear Riaz

Thanks for your reply. I have already read these articles and followed such methods to calculate drug loading on NP's but I was interested to know that how we can calculate drug loading through TGA for the sake of knowledge.

Munir,

Try searching on the net. You may not get a direct answer but analysis may lead to answers. Better would be to experiment! if you are aware of the TGA working and result inference from that. The mixed polymer constituent should show different characteristics and so will be the empty NPs. Let us know results of your experiment, if you run!

I guess, you also have read this!

This paper has stated the NP's graph of TGA that I have also. But in this paper, there is no method described that how we can calculate drug loading through TGA.

I searched many for my question but don't get any answer. So I think I should left it.

Better would be to experiment! if you are aware of the TGA working and result inference from that. The mixed polymer constituent should show different characteristics and so will be the empty NPs. Let us know results of your experiment, if you run!

I also have the same doubt. whether TGA can be used to find drug loading in nanoparticles. I am working on mesoporous silica nanoparticles. I load the drug in nanoparticles. I did tga for mesoporous silica nanoparticles and mesoporous silica nanoparticles with drug. Temperature range is 30-900 degree celsius. The weight loss of mesoporous silica is 7% and weight loss of mesoporous silica with drug is 40%. so drug loading % = 40 - 7 = 33%. This is correct?

Dear Prabhuraj

I have still same question with no answer.

Thanks for your reply. Do you check drug loading % by uv matched with drug loading % by tga? Awaiting for your reply.

I have checked drug loading and % encapsulation efficiency by UV method but not by TGA. Although I have done a lot of work for that question "how we can calculate % drug loading by TGA method" but did not receive any reliable answer.

Have you done TGA of the drug that you have loaded in NPs? If weight loss of NPs with drug is 40% then the weight loss of the drug will be greater than 40% at the same temperature.

Thanks for your reply muhammed usman munir. I did TGA for nanoparticle , drug, nanoparticle with drug in the range of 30-900 degree celsius at nitrogen atmosphere. The weight loss for nanoparticle is 8.6%, drug is 70.187, nanoparticle with drug is 21.24%. Here drug is loaded in nanoparticle which generally leads to increase in molecular weight of nanoparticle logically. so, there will be more weight loss than nanoparticle. Drug loading  % =nanoparticle with drug - nanoparticle = 21.24-8.6 = 12.3%. This way of calculating drug loading is correct?

Dear Muhammad Usman Munir , 

    I did TGA for nanoparticle and nanoparticle with drug. Temperature range : 25 - 900 degree celsius. I found a paper recently online. I calculate drug loading with the help of that paper. I attach the image (drug loading %) and paper for your reference. Drug loading % calculated by UV method is 10.7%.Drug loading by TGA is 9.58%. one or two drug loading % by uv can be varied. Its not a big problem. I consider only 101-600 degree celsius. I am not consider from 25-100 degree because there will be presence of water molecules in that range. Give your suggestions.

Dear Prabhuraj

As in your case, % weight loss of empty NPs and drug loaded NPs at temp 101-600 (Celcius) are 4.598 and 12.531 respectively. So % drug loading will be 9.58% (12.531-4.598). Although we can estimate % drug loading through TGA but the appropriate method for drug loading and encapsulation is UV method.

Dear Muhammad Usman Munir,

         You are correct. Now more papers use both TGA and uv method to find the drug loading % nowadays. You can see the attached paper in the last message. We can use TGA to confirm the calculated drug loading % by UV. From my experience, one can follow both in their research.

TGA is used to reconfirm or verify either the results of UV are correct or not.