I have a film sample (7mg). The total mass of the film for this sample is about 210 mg with 40 mg of the drug embedded. The dissolution media is 90 ml. I have the absorbances and the equation from the calibration curve in ppm.

Could someone tell me how to calculate the percentage of drug released? Should it only include the 7mg sample or must the total mass be correlated (210 mg) according to pharmacopoeia? I have done the calculations but they seem to be less than what I expected based on the network. Please give me ideas on the correct calculation method.

Thanks.