Application of Elements of Quality by Design to Development and Optimization of HPLC Method for Fingolimod

Purpose: A HPLC method for Fingolimod was developed using a Quality by Design concept. QbD has gained importance in recent times due to regulatory requirements. Actual study was started after determination of target profile and qualification of instrument. Methods: Separation was carried on a Grace C-8 column (4.6 x 250 mm, 5-mu m particle size).The composition of mobile phase was methanol and 20 mM ammonium formate buffer of pH5.8 in gradient mode HPLC method development is affected by critical factors like pH, flow rate and mobile phase composition. Results: To study the effects of these three factors on USP tailing, Box Behnken optimization model was applied. Desirability of the model was set at Tailing less than 1.2.Analysis of results was done using surface diagrams. Verification of Software generated results was done by taking six replicates of the run. Thus developed and optimised method was Finally validated as per ICH guideline. Conclusion: A Quality by Design approach has been successfully utilised in method development of the Fingolimod in bulk. All key aspect of QbD were tried to be implemented in said study. Systematic approach was utilized for method development which includes beginning with determination of target profile characteristics, instrument qualification, risk assessment, design of experiment and validation. Three factors i.e. Ph, flow rate and methanol concentration were analysed for their effect on USP tailing as a responce. Interaction and quadratic effect of the factors were studied with least possible runs by using Box Behnken model. Response surface diagrams and contour plots were studied for coming to conclusion which factors are affecting response and their limits were recorded. Optimum run condition was obtained; Replicates of run having optimized condition were taken to confirm the predicted response with actual response.