Spectrometric Assessment of Intralot and Interlot Variability in Mycophenolate Mofetil for Injection Using Near-Infrared Spectrometry and Nonparametric Subcluster Detection.

Mycophenolate Mofetil for Injection is an antimetabolite immunosuppressant supplied as a sterile, lyophilized powder containing 500 mg of active drug per single-dose vial for intravenous administration. As a prodrug of mycophenolic acid, it selectively and reversibly inhibits inosine monophosphate dehydrogenase to block de novo guanosine nucleotide synthesis and suppress lymphocyte proliferation, carrying boxed warnings for embryofetal toxicity, serious opportunistic infections, and malignancies. Nondestructive Fourier transform near-infrared spectrometry coupled with principal component analysis and the Bootstrap Error-Adjusted Single-sample Technique was utilized to evaluate intralot and interlot spectral consistency across drug vials. Intra-lot analysis of a single 15-vial batch (Lot 2515203) revealed heterogeneity and outliers, with individual vials deviating up to 11.6 multidimensional standard deviations from the main cluster center. Interlot evaluation of a 464-vial spectral library spanning 18 distinct manufacturing lots demonstrated persistent two-group subclustering, with Principal Component 1 accounting for only 87.82% of total spectral variance. Nonparametric FSOB density estimation confirmed statistically significant subclustering across the multi-lot library (p = 0.02), dividing the sample set into two distinct groups (14.2% vs. 85.8%). While these findings do not establish active ingredient adulteration or excessive impurities, the observed intralot and interlot spectral variations indicate that the manufacturing process may have operated outside an ideal state of statistical process control, underscoring the value of PAT monitoring in health-system quality assurance.