Aztreonam for injection (Fresenius Kabi) is a sterile, nonpyrogenic, sodium-free lyophilized, off-white to slightly yellow solid containing approximately 780 mg of arginine per gram of aztreonam, indicated for the treatment of specific infections caused by susceptible Gram-negative microorganisms. Ensuring the physical and chemical homogeneity of this lyophilized matrix is critical for consistent clinical efficacy; however, near-infrared (NIR) spectrometric screening coupled with high-dimensional principal component analysis (PCA) reveals complex, multidimensional inconsistencies within the commercially available product. Initial localized screening demonstrated significant intra-lot variability, with spectral data points forming a distinct toroidal pattern characteristic of cyclical oscillatory dynamics and an unstable mathematical average state. Extreme multidimensional outliers extending up to 5.6 standard deviations from the data centroid were observed diverging along multiple orthogonal trajectories, indicating that the intra-lot instability is driven by multiple independent physical and chemical mechanisms rather than a single processing failure. Expanding the evaluation to a comprehensive inter-lot analysis of 152 vials across 12 manufacturing lots confirmed that these inconsistencies persist at a systemic scale. The primary principal components divided the spectral library into two major, statistically distinct subpopulations, with asymmetric outlier distributions suggesting intermittent lapses in process control. Furthermore, projections in higher-order dimensions (PCs 7 through 9) isolated an entire manufacturing lot due to batch-level structural deviations possibly driven by trace moisture and aliphatic framework fluctuations. Nonparametric probability-density contour evaluations utilizing the FSOB algorithm and quantile-quantile (QQ) plots mathematically validated the presence of distinct subpopulations (rtn=0.99, rts=0.88, p=0.02). Ultimately, these findings indicate that the manufacturing process is subjected to multiple, independent sources of instability, suggesting operations may intermittently fall outside a strict state of control.

Methacholine chloride is a parasympathomimetic (cholinergic) bronchoconstrictor agent. It is administered exclusively in solution via inhalation for diagnostic purposes, strictly indicated for diagnosing bronchial airway hyperreactivity in adults and pediatric patients aged five years and older who lack clinically apparent asthma. Spectrometric evaluation of a single manufacturing batch, lot P3055R, revealed distinct anomalies, most notably a broad absorbance peak at 5131 cm- 1 that was present in certain vials but entirely absent in others. Principal component analysis orthogonally quantified this intralot variance, demonstrating that Vial 1 deviated by 7.3 standard deviations (SDs) from the cluster center, while a subsequent rotation identified Vial 4 as an outlier positioned 4.3 SDs away. Expanding the evaluation to a 39-vial library across three distinct lots (P3055R, P3048R, and P4009S) demonstrated significant interlot structural variance. This complexity required nine full principal components to model 99.97% of the cumulative variation. Furthermore, the application of the nonparametric FSOB (Fast Son of BEST) subcluster analysis algorithm inside the spectral clusters confirmed the geometric separation of the data into statistically significant sub-groups. Specifically, vials 8 through 18 naturally separated from the remaining library (vials 1 through 7 and 19 through 39). This geometric separation spanned an extensive correlation distance of 58.8 SDs, defined by the statistical metrics rtn=0.9944, rts=0.8903, and σ=0.0019, with probability-density perturbations achieving a significance level of p=0.02. While these quantified deviations do not definitively prove the presence of adulteration or an excess level of impurities, they strongly indicate that the manufacturer's production pipeline may have drifted outside of a state of strict process control, warranting further investigation.

Acetazolamide for Injection, USP is a sterile, preservative-free carbonic anhydrase inhibitor primarily indicated for the treatment of acute mountain sickness, fluid volume overload associated with heart failure, and elevated intraocular pressure in glaucoma. This research utilized Fourier transform near-infrared spectrometry (FT-NIR) to evaluate the intra-lot variability of 12 vials of Mylan Institutional Acetazolamide 500 mg. While all sampled vials appeared visually identical as white to yellowish-white powders, FT-NIR analysis identified significant spectral heterogeneity, particularly in the range of 4200 to 5200 cm-1. Statistical analysis using the Bootstrap Error-Adjusted Single-sample Technique (BEST) and Principal Component Analysis (PCA) identified vial 6 as a prominent statistical outlier. This vial exhibited a distinct absorbance peak at 4851 cm-1, which was suggested to be a shift from a peak at 5173 cm-1 and was positioned 4.03 standard deviations from the center of the lot cluster in multidimensional spectral hyperspace. These results suggest that the manufacturing process may have been operating outside of a state of process control. Given the ongoing national shortages of acetazolamide as of January 2026, such quality assurance screenings are critical for maintaining supply chain transparency and ensuring the reliability of medication used in evolving clinical protocols.

Ceftriaxone for injection, USP is a sterile, semisynthetic, broad-spectrum cephalosporin antibiotic for intravenous or intramuscular administration. Ceftriaxone sodium is a white to yellowish crystalline powder which is readily soluble in water, sparingly soluble in methanol and very slightly soluble in ethanol. The color of ceftriaxone sodium solutions ranges from light yellow to amber, depending on the length of storage, concentration and diluent used. Each vial contains ceftriaxone sodium equivalent to 250 mg, 500 mg, 1 gram or 2 grams of ceftriaxone activity. Ceftriaxone sodium contains approximately 83 mg (3.6 mEq) of sodium per gram of ceftriaxone activity. Intra-lot variability was detected in the spectra of 6 vials of ceftriaxone sampled from one lot. One of the vials was more than 8.3 multidimensional SDs away from the center of the cluster of the other 5 vials from the same lot, suggesting that the manufacturing process may not be in a state of control. Interlot variability was detected between two lots of the drug using a subcluster detection test (rtn=0.9629, rts=0.9148, p=0.02).

Meropenem for Injection, USP is a sterile, pyrogen-free, white to pale yellow crystalline powder and is supplied in vials containing sufficient meropenem to deliver 1 g for intravenous administration. The Drug Quality Task Force at the University of Kentucky has found variability in the near-infrared spectra of meropenem samples. The variability was found both within a lot (where one vial from six was 12.0 SDs from the other 5 vials) and between lots of the drug (where 8 vials were >3 SDs from the center of the library, and one of those was 6.1 SDs away from the center of the library). This variability was detected using a statistical analysis of the spectra that included principal component analysis (PCA) and the BEST metric. Inter-lot variability was assessed using a spectral library of 90 meropenem vials obtained from 15 lots of drug from the same manufacturer. The results suggest that the drug may have been manufactured while the manufacturing process was operating outside of a state of process control.

Methylprednisolone sodium succinate for injection, USP is an anti-inflammatory glucocorticoid. The active ingredient is methylprednisolone sodium succinate, which is the sodium succinate ester of methylprednisolone. The substance is a white or nearly white, odorless, hygroscopic, amorphous solid. It is highly soluble in water and alcohol, insoluble in chloroform, and only slightly soluble in acetone. This injectable form of the drug is indicated for the treatment of various conditions, including some allergic states, dermatologic, endocrine, gastrointestinal, hematologic, neoplastic, nervous system, ophthalmic, renal, respiratory, and rheumatic disorders. The analysis of a single lot of methylprednisolone sodium succinate revealed significant intra-lot variability in the near-infrared spectra. Differences were visually apparent in the absorbance peaks, particularly in the ranges of 4500 to 5000 cm-1 and 6000 to 6500 cm-1. Further examination of a zoomed-in region (7000 to 8500 cm-1) showed two spectra that were statistically significant outliers, positioned at 4.4 and 5.9 standard deviations (SDs) from the center of the sample cluster. An analysis of a spectral library containing 242 vials of methylprednisolone sodium succinate from 26 different lots found significant interlot variability and statistically confirmed the presence of distinct subclusters. To statistically validate the visual findings, a subcluster detection algorithm was applied to the spectral data. The algorithm confirmed that two distinct groups exist within the spectral data. The measured correlation value (rts =0.8704) was below the 98% confidence level threshold (rtn =0.9916), leading to the acceptance of the alternative hypothesis that more than one group is present.

Thyrotropin alfa is a recombinant heterodimeric glycoprotein that serves as a highly purified form of human thyroid stimulating hormone (TSH). It is produced through recombinant DNA technology within a genetically modified Chinese hamster ovary (CHO) cell line. The molecule is structurally complex, consisting of two non-covalently linked subunits: an alpha subunit (92 amino acid residues) with two N-linked glycosylation sites, and a beta subunit (118 residues) containing one N-linked glycosylation site. The resulting amino acid sequence is identical to that of human pituitary TSH. Thyrotropin alfa is supplied as a sterile, non-pyrogenic, white to off-white lyophilized product, intended for intramuscular (IM) administration after reconstitution with Sterile Water for Injection, USP. Each vial of Thyrogen contains 1.1 mg thyrotropin alfa, 36 mg mannitol, 5.1 mg sodium phosphate, and 2.4 mg sodium chloride. The intralot analysis of the 12 vials sampled from lot EY0155 revealed significant differences in the drug product within the same manufacturing lot, as evidenced by both spectral plots and multivariate analysis. The visual differences were observed in the following wavenumber regions: 4000 to 5000 cm-1, 5150 cm-1, and the 6700 cm-1 regions. The differences seen at 5150 cm-1 are very likely a difference in moisture content. 25% of the vials were flagged as outliers, with vials appearing 3.3, 3.8, and 5.3 SDs from the center of the cluster of 12 vials. The interlot analysis of a spectral library containing 171 vials from 18 different lots of thyrotropin alfa demonstrated tremendous variability in the near-infrared absorption profiles across the samples. Obvious differences were observed in the spectra of the library at several wavenumber regions, including around 5900 and 6650 cm-1. The ratio between two peak sizes between 5900 and 5950 cm-1 was dramatically variable. Differences were also noted around 4250, 4400, and 4540 cm-1, and from 4700 to 4800 cm-1. Only one vial was an outlier, appearing 7.8 SDs away from the center of the library spectral cluster. Some literature suggests differences in the spectra of vials may reflect differences in the stability and efficacy of the drug.

Azacitidine injections are used to treat specific types of blood cancers. They work by interfering with the growth of cancer cells. Azacitidine for injection is a nucleoside metabolic inhibitor indicated for the treatment of (a) Adult patients with the following FAB myelodysplastic syndrome (MDS) subtypes: Refractory anemia (RA) or refractory anemia with ringed sideroblasts (RARS) (if accompanied by neutropenia or thrombocytopenia or requiring transfusions), refractory anemia with excess blasts (RAEB), refractory anemia with excess blasts in transformation (RAEB-T), and chronic myelomonocytic leukemia (CMMoL), and (b) Pediatric patients aged 1 month and older with newly diagnosed Juvenile Myelomonocytic Leukemia (JMML). Intra-lot variability was initially detected in one lot of azacitidine for injection in which 17% of the samples scanned in the lot were more than 5 multidimensional SDs from the center of the lot cluster. After the intra-lot variability was detected, inter-lot variability was measured in a spectral library comprising 8 lots of azacitidine for injection.

The University of Kentucky's Drug Quality Task Force (DQTF) conducted a study to perform consumer-level quality assurance screening of vasopressin injections used in their healthcare pharmacies. The primary objective was to identify potential quality defects by examining intralot and interlot variability using Raman spectrometry and statistical analyses. Raman spectra were collected noninvasively and nondestructively from vasopressin vials (n=51) using a Thermo Scientific Smartraman DXR3 Analyzer. Data processing techniques, including smoothing with cubic splines and Multiplicative Scatter Correction (MSC), were applied to prepare the spectra for analysis. Statistical analyses employed included the Bootstrap Error-Adjusted Single-sample Technique (BEST), Principal Component Analysis (PCA), and subcluster detection to assess variability and detect unusual samples. The study revealed significant intralot and interlot variability in the vasopressin samples. Analysis of Raman spectral graphs from vials in lot 22040L1C0 showed multiple subgroups within a single lot, indicating variability in chemical composition. Examination of the entire spectral library, which included vials from two different lot numbers, revealed four distinct groups that did not correspond to lot numbers. A subcluster detection test confirmed the presence of at least two distinct chemical compositions in samples from both lots, rejecting the null hypothesis that the groups have the same scale and location. While these spectrometric results do not conclusively prove an excess level of impurities or adulteration, they suggest that the manufacturing process may have been operating outside of a state of process control. These findings highlight the need for further investigation into potential process control issues to ensure consistent manufacturing processes and maintain drug quality and efficacy.

Abatacept is a medication administered through intravenous infusion. It is supplied as a sterile, white, preservative-free, freeze-dried powder. Each vial of drug contains 250 mg abatacept, maltose, monobasic sodium phosphate, and sodium chloride for administration. Abatacept is a fusion protein consisting of the extracellular domain of CTLA-4 linked to the modified Fc portion of human immunoglobulin G1. It is produced using recombinant DNA technology. Abatacept is indicated for moderately to severely active rheumatoid arthritis in adults and polyarticular juvenile idiopathic arthritis in pediatric patients 6 years of age and older. It can be used as monotherapy or in combination with other disease-modifying antirheumatic drugs or methotrexate. Inter-lot variability was detected in a library of 132 vials spread across 34 lots of abatacept-maltose for injection by the University of Kentucky Drug Quality Task Force. A subcluster detection test was run on 13 vials that were shown to be an outlier group (rtn=0.9940, rtest=0.9551, rlim=0.9865, p=0.02). Five of these vials individually appeared 4 or more standard deviations from the library cluster.

Chlorothiazide sodium for injection, USP, is a diuretic and antihypertensive medication in the form of a white or practically white, sterile, lyophilized powder. Each vial contains 500 mg of chlorothiazide sodium, equivalent to 500 mg of chlorothiazide, and 250 mg of mannitol as an inactive ingredient. The pH is adjusted with sodium hydroxide. Chlorothiazide sodium has a molecular weight of 317.71 amu. Since 2020 there have been multiple national shortages of chlorothiazide. Recent studies target chlorothiazide's low bioavailability, aiming to enhance it through nanoparticle production via a supercritical method. The drug's solubility in supercritical carbon dioxide (scCO2) is vital, with measurements ranging from 0.417×10-5 to 1.012×10-5 mole fraction under specific conditions. Adding co-solvents, like ethanol, DMSO, and acetone, to scCO2 boosts solubility, with ethanol proving most effective, enhancing solubility by 2.02-11.75 times. Intra-lot variability was discovered in a sample of a lot of chlorothiazide sodium by the University of Kentucky Drug Quality Task Force. Two vials of six screened in one lot were displaced from the center of the lot by 4.0 and 4.2 SDs, respectively. Inter-lot variability was confirmed in the near-IR spectra of 204 vials obtained from 28 different lots of chlorothiazide sodium. Using full spectrum BEST analysis 13 vials (6.4%) were outliers.

Purpose The University of Kentucky Drug Quality Study team briefly reviews the growing concerns over pharmaceutical manufacturing quality in the globalized environment, reviews the historical approach by the US Food and Drug Administration (FDA) that prioritizes process over product in enforcing quality with manufacturers, reviews the science of process analytical technology (PAT) such as near-infrared (NIR) spectroscopy, illustrates the use of PAT methods for assessing uniformity and quality in injectable pharmaceuticals, and demonstrates the application of NIR spectroscopy in a health-system pharmacy setting while maintaining current good practice quality guidelines and regulations (cGxP). Summary Given that the current approach to monitoring quality in pharmaceutical manufacturing was developed in the late 1960s at a time when manufacturing was mostly domestic, the current approach prioritizes process over product, and the global footprint of manufacturing is straining federal resources to fulfill their task of monitoring quality, an approach to augment the quality monitoring process has been developed. PAT methodologies are supported by FDA for monitoring quality and offer a fast, low-cost, nondestructive solution. Given that the Accreditation Council for Pharmacy Education has not required qualitative/quantitative analysis and drug assaying in the pharmacy curriculum for several decades, the authors spend time explaining the science behind one of these PAT methodologies, NIR spectroscopy. This primer reviews the application of this technology in the health-system pharmacy setting and the relevant clinical applications. Conclusion Utilizing PAT methodologies such as NIR spectroscopy, health-system pharmacies can gain insights about whether process controls are in place or lacking in FDA-approved formulations.

The U.S. Food and Drug Administration (FDA) is a worldwide leader among analogous regulatory organizations in other countries. The FDA uses current good manufacturing practices to regulate the processes that produce drugs. Nevertheless, investigative journalists have pointed out problems in the drug supply, and pharmacies are not required to test the drugs they receive. The University of Kentucky Drug Quality Study does perform screening on the sterile injectable drugs that it receives and regularly reports new findings to FDA, practitioners, and the public. A Sentinel Screening Network of academic health systems could provide independent data on drug quality to FDA not available through manufacturers.

SOLU-CORTEFⓇ Sterile Powder is a type of anti-inflammatory glucocorticoid that contains hydrocortisone sodium succinate as its active ingredient. It can be administered intravenously or intramuscularly, and comes in several packages including 100 mg plain vials without diluent. The diluent, which is part of the ACT-O-VIAL system, contains only Water for Injection and no preservatives. The pH of each formula is adjusted with sodium hydroxide to ensure it falls within the specified range of 7 to 8 after reconstitution. Intralot variability was detected in lot GA6092. Measuring in the PC subspace using just PCs 4, 5 and 6, vial 12 plots 4.2 BEST SDs from the center of the cluster, and vial 7 is 3.7 SDs from the center. Vial 18 appears 3.1 SDS from the center of the cluster (3/18, 17%). Interlot variability was also found in the spectral library (lots GA6092, GK7048, GM6839, GR8925, FL8062, FN6860, FR1914, and FR5098) containing the spectra of 126 hydrocortisone sodium succinate vials.

Thyrotropin alfa is a heterodimeric glycoprotein containing human thyroid stimulating hormone (TSH). It is used as an adjunctive diagnostic tool for serum thyroglobulin (Tg) testing with or without radioiodine imaging in the follow-up of patients with well-differentiated thyroid cancer who have previously undergone thyroidectomy. Inter-lot variability in the Fourier transform near-infrared spectra of 30 samples obtained from four separate lots of Thyrogen® was detected in the Drug Quality Study (DQS). The vials fell into two distinct groups (rtst = 0.90, rlim= 0.98, p=0.02). In addition, one vial of the 30 (3%) appeared 4.7 multidimensional SDs from all of the other vials, suggesting that it also represents a different material.

Dantrolene sodium is a direct-acting skeletal muscle relaxant. Dantrolene sodium for injection is indicated, along with suitable supportive measures, for the management of sudden, severe hypermetabolism of skeletal muscle typical of malignant hyperthermia crises in patients of any age. The formulation scanned in this work was designed to be injected intravenously. Intra-lot and inter-lot variability in the spectra of REVONTO™ (dantrolene sodium) was measured in the Drug Quality Study (DQS) using Fourier transform near-infrared spectrometry (FTNIR). Spectra of 69 vials from lot 20REV01A contained two groups (n1=56 vials, n2=13 vials) when scanned with an FTNIR. The two groups of spectra in lot 20REV01A were found to be 66.7 SDs apart using a subcluster detection test, suggesting that the two groups were manufactured differently. As a result, all available samples of dantrolene were examined. A library of spectra of 141 vials of dantrolene from 4 lots were found to contain 3 separate groups, also suggesting that different vials contain different materials.

This study employed Fourier Transform near-infrared spectrometry to assess the quality of vecuronium bromide, a neuromuscular blocking agent. Spectral data from two lots of vecuronium were collected and analyzed using the BEST metric, principal component analysis (PCA) and other statistical techniques. The results showed that there was variability between the two lots and within each lot. Several outliers in the spectral data suggested potential differences in the chemical composition or sample condition of the vials. The outliers were identified and their spectral features were examined. A total of eight unique outliers were found in the PC space from PCs 1 to 9, so 22% of the total vials were outliers. The study findings suggest that the manufacturing process of vecuronium bromide may have been operating outside of a state of process control. Further investigation is needed to determine the source of these variations and their impact on the safety and efficacy of the drug product.

This assessment of subcluster detection in analytical chemistry offers a nonparametric approach to address the challenges of identifying specific substances (molecules or mixtures) in large hyperspaces. The paper introduces the concept of subcluster detection, which involves identifying specific substances within a larger cluster of similar samples. The BEST (Bootstrap Error-adjusted Single-sample Technique) metric is introduced as a more accurate and precise method for discriminating between similar samples compared to the MD (Mahalanobis distance) metric. The paper also discusses the challenges of subcluster detection in large hyperspaces, such as the curse of dimensionality and the need for nonparametric methods. The proposed nonparametric approach involves using a kernel density estimator to determine the probability density function of the data and then using a quantile-quantile algorithm to identify subclusters. The paper provides examples of how this approach can be used to analyze small changes in the near-infrared spectra of drug samples and identifies the benefits of this approach, such as improved accuracy and precision.

Carfilzomib is a prescription injectable drug approved for use by the FDA as an antineoplastic agent, part of a drug class of medications known as proteasome inhibitors, and used to stop and slow the growth and progression of cancer cells within the body. The drug is approved as an agent to treat multiple myeloma. It is provided as a single-use vial that contains 60 mg of carfilzomib as a sterile, white to off-white lyophilized cake or powder. Intra-lot and inter-lot variability in the spectra of carfilzomib vials was detected in the Drug Quality Study (DQS) using Fourier transform near-infrared spectrometry (FTNIR). One of 12 vials of lot 1143966 manufactured for Onyx Pharmaceuticals, Inc. appeared 4.7 multidimensional standard deviations (SDs) from the other 11 vials in a 3-D space formed by the first 3 principal components, which captured 81% of the total spectral variation. Spectra of 168 vials from 18 lots in the spectral library formed two groups in the 3-D space formed by the first 3 principal components. One group contained 155 vials and the other group contained 13 vials. The 2 groups had different locations and scales using a subcluster detection test at p=0.02.

Intra-lot and inter-lot variability in dacarbazine was detected in the Drug Quality Study (DQS) using Fourier transform near-infrared spectrometry (FTNIR). One vial of six vials sampled from Fresenius Kabi Lot 6125612 appeared 7.8 SDs from the center of the rest of the vials on the DQS FTNIR screening assay. Spectra of 54 vials from six lots in the library clustered in two groups (p=0.02), suggesting they represent different material.