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Updated: Jun 29, 2025
Quantification of the Immunosuppressant Tacrolimus on Dried Blood Spots Using LC-MS/MS
Published on: November 8, 2015
Combating Alcohol Adduct Impurity in Immunosuppressant Drug Product Manufacturing: A Scientific Investigation for
Vasanthakumar Sekar1, Devarajan Vedhachalam2, ArunKumar Vb2
1Pfizer Healthcare India Private Limited, Medicinal Sciences-Pharmaceutical Sciences Small Molecules, Pfizer Research & Development, 8th Floor, Block C, IIT Madras Research Park, Kanagam Road, Taramani, Chennai, India, 600113. vasanthakumar.sekar@pfizer.com.
Objective:
This research aims to elucidate critical impurities in process validation batches of tacrolimus injection formulations, focusing on identification and characterization of previously unreported impurity at RRT 0.42, identified as the tacrolimus alcohol adduct. The potential root causes for the formation of new impurity was determined using structured risk assessment by cause and effect fishbone diagram. The primary objective was to propose mitigation plan and demonstrate the control of impurities with 6 month accelerated stability results in development batches.
Methods:
The investigation utilizes method validation and characterization studies to affirm the accuracy of quantifying the tacrolimus alcohol adduct. The research methodology employed different characterization techniques like rotational rheometer, ICP‒MS, MALDI-MS, 1H NMR, 13C NMR, and DEPT-135 NMR for structural elucidation. Additionally, the exact mass of the impurity is validated using electrospray ionization mass spectra.
Results:
Results indicate successful identification and characterization of the tacrolimus alcohol adduct. The study further explores the transformation of Tacrolimus monohydrate under various conditions, unveiling the formation of Tacrolimus hydroxy acid and proposing the existence of a novel degradation product, the Tacrolimus alcohol adduct. Six-month data from development lots utilizing Manufacturing Process II demonstrate significantly lower levels of alcohol adducts.
Conclusions:
Manufacturing Process II, selectively locates Tacrolimus within the micellar core of HCO-60, this prevent direct contact of ethanol with Tacrolimus which minimizes impurity alcohol adduct formation. This research contributes to the understanding of tacrolimus formulations, offering ways to safeguard product integrity and stability during manufacturing and storage.
