Screening for quality with process analytical technology in a health-system pharmacy: A primer

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.

Spectrometric Assessment of Generic and Brand Drug Quality for a Sentinel Screening Network

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.

Variability in Content of Hydrocortisone Sodium Succinate

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.

Quality Variations in Thyrotropin Alfa

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 (r_tst = 0.90, r_lim= 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.

Spectrometric Analysis of Dantrolene Sodium

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.

Assessment of Vecuronium Quality Using Near-Infrared Spectrometry

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.

Spectral Intra-Lot and Inter-Lot Variability in Carfilzomib

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.

Spectrometric Analysis of Process Variations in Remifentanil

ULTIVA® (remifentanil hydrochloride) is a sterile, nonpyrogenic, preservative-free, white to off-white lyophilized powder for intravenous (IV) administration after reconstitution and dilution. Each vial contains 1, 2, or 5 mg of remifentanil base; 15 mg glycine; and hydrochloric acid to buffer the solutions to a nominal pH of 3 after reconstitution. ULTIVA® is a μ-opioid agonist with rapid onset and peak effect, and short duration of action. Intra-lot and inter-lot variability in the spectra of ULTIVA® was measured in the Drug Quality Study (DQS) using Fourier transform near-infrared spectrometry (FTNIR). In 6 vials sampled, 1 came from lot 220453F while 5 came from lot 30020BF. The 1 vial sampled from lot 220453F appeared 122 multidimensional SDs from the other vials from lot 30020BF, suggesting that it represents a different formulation or material. Consequently, additional spectra from other lots were analyzed. Spectra of 90 vials from 9 lots in the spectral library contained vials that were outside the main group (50.3 SDs using a subcluster detection test), suggesting that the 35 library vials (39% of the total) contain different materials from the other 55 vials.

Potential Process Control Issues with Pemetrexed

Pemetrexed is a folate analog metabolic inhibitor used in treatment of locally advanced or metastatic nonsquamous non-small cell lung cancer and for mesothelioma. Intra-lot and inter-lot variability in the spectra of ALIMTA® was detected in the Drug Quality Study (DQS) using Fourier transform near-infrared spectrometry (FTNIR). One vial of 12 (8%) sampled from lot S20I013A appeared 3.0 multidimensional SDs from the other vials, suggesting that it represents a different material. Consequently, additional spectra from other lots were analyzed. Spectra of 147 vials from 23 lots in the spectral library contained 14 vials that were outside the main group (26.4 SDs using a subcluster detection test), suggesting that the 14 library vials (9.5% of the total) also contain differing materials.

Variability in Content of Piperacillin and Tazobactam Injection

Piperacillin and Tazobactam Injection is a combination product consisting of a penicillin-class antibacterial, piperacillin, and a beta-lactamase inhibitor, tazobactam, indicated for the treatment of patients with moderate to severe infections caused by susceptible isolates of bacteria. In the past decade some quality problems have been noted by the US Food and Drug Administration (FDA) with the Apotex Corp. manufacturing. Intra-lot and inter-lot variability in the spectra of Piperacillin and Tazobactam Injection 3.375 g was detected in the Drug Quality Study (DQS) using Fourier transform near-infrared spectrometry (FTNIR). One vial of 6 (17%) sampled from lot AD103008F3 appeared 14.4 multidimensional SDs from the other vials, suggesting that it represents a different material. Spectra of 132 vials from 19 lots in the spectral library contained 4 vials that were outside the group (21.0 SDs using a subcluster detection test), suggesting that the 4 library vials (3%) also contain differing materials.

Levothyroxine Variations by Process Analytical Technology

Intra-lot and inter-lot variability in the spectra of levothyroxine was detected in the Drug Quality Study (DQS) using Fourier transform near-infrared spectrometry (FTNIR). Two vials of 12 vials sampled from Athenex lot AFN102 appeared 10.1 and 9.1 SDs from the center of the rest of the vials on the DQS FTNIR screening assay. Spectra of 108 vials from six lots in the library clustered in two groups (p=0.02), suggesting they represent different material.

Lack of Content Uniformity in MMR Vaccine

The measles, mumps, and rubella (MMR) vaccine is a vaccine used to prevent measles, mumps, and rubella (German measles). The vaccine is mandated for children to attend public school in nearly all US states. However, measles cases have been increasing in the past decade, and quality problems have recently been noted by the US Food and Drug Administration (FDA) with the vaccine manufacturer. Intra-lot and inter-lot variability in the spectra of MMR (measles, mumps, and rubella) vaccine was detected in the Drug Quality Study (DQS) using Fourier transform near-infrared spectrometry (FTNIR). Six vials of 12 (50%) sampled from Merck lot U006488 appeared 14.5 SDs from the other vials on a subcluster detection test, suggesting that they represent different material. Spectra of 198 vials from 12 lots in the spectral library contained 140 vials in one tight ellipsoidal group, and 58 vials (30%) were outside that group (39.7 SDs using a subcluster detection test), suggesting that the library vials also contain differing materials.

FTNIR Spectrometry of Micafungin Sodium Quality

Intra-lot and inter-lot variability in the spectra of micafungin was detected in the Drug Quality Study (DQS) using Fourier transform near-infrared spectrometry (FTNIR). Two vials of 6 vials sampled from Fresenius Kabi lot ACP106 appeared 7.9 and 14.0 standard deviations (SDs) from the center of the rest of the vials on the DQS FTNIR screening assay. Spectra of 48 vials from 7 lots in the library showed 2 outliers at 8.3 and 9.8 SDs from the center of the rest of the library, suggesting they represent different material.

Spectrometric Results of Process Variations in Dacarbazine

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.

Intra-Lot and Inter-Lot Variability in Cosyntropin

Intra-lot and inter-lot variability in cosyntropin was detected in the DQS using Fourier transform near-infrared spectrometry. One vial of 12 sampled from Sandoz Lot0200062 appeared 6.9 SDs from the center of the rest of the vials, and another was 4.3 SDs away. Spectra of 102 vials from 7 lots in the library clustered in two groups (p=0.02).

Intra-Lot and Inter-Lot Variability in Ceftaroline Fosamil

Intra-lot and inter-lot variability in ceftaroline fosamil was detected in the DQS using Fourier transform near-infrared spectrometry. One vial of 18 sampled from Lot0013E06 appeared 9.0 SDs from the center of the rest of the vials. Six lots in the spectral library clustered in two large groups.

Population Data-Driven Formulation of a COVID-19 Therapeutic

This study is designed to utilize computer modeling of the US population through NHANES to reduce the need for preclinical formulation and toxicology studies of an Ebola anti-viral (BSN389) being repurposed for COVID-19, and to thereby speed the candidate therapeutic to the clinic.

Safety and Efficacy of D-Tagatose in Glycemic Control in Subjects with Type 2 Diabetes

The primary objectives of this study were to evaluate the treatment effect of D-tagatose on glycemic control, determined by a statistically significant decrease in hemoglobin A1c (HbA1c), and safety profile of D-tagatose compared to placebo. The secondary objectives were to evaluate the treatment effects on fasting blood glucose, insulin, lipid profiles, changes in BMI, and the proportion of subjects achieving HbA1c targets of <7%. Type 2 diabetic patients not taking any blood glucose lowering medications were administered either 15 g of D-tagatose dissolved in 125-250 ml of water three times a day or placebo with meals. Reduction in HbA1c was statistically significant compared to placebo at all post-baseline time points in the ITT population. Additionally, secondary endpoints were achieved in the ITT population with regard to LDL, total cholesterol, fasting blood glucose, and proportion of subjects achieving HbA1c targets of <7%. D-tagatose was unable to lower triglycerides or raise HDL compared to placebo. A subgroup LOCF analysis on the ITT US population showed a greater and statistically significant LS mean reduction in HbA1c in the D-tagatose group at all post-baseline visits. Based on these results it is concluded that in the ITT population D-tagatose is an effective single agent at treating many of the therapy targets of type 2 diabetes including lowering fasting blood glucose and HbA1c, and lowering of LDL and total cholesterol.

Effects of Three Low-Doses of D-Tagatose on Glycemic Control Over Six Months in Subjects with Mild Type 2 Diabetes Mellitus Under Control with Diet and Exercise

The primary objective of this study was to evaluate the safety and the effect of D-tagatose on the glycemic control of subjects with type 2 diabetes as determined by HbA_1c levels at the end of 6 months of therapy using the subject's own baseline HbA_1c level as a comparator. The determination of the minimal dose required to cause a statistically significant reduction in HbA_1c was of particular interest. Eight weeks after screening, the qualifying subjects were randomized to receive one of three doses of D-tagatose: 2.5 g TID, 5.0 g TID or 7.5 g TID. Blood levels of HbA_1c, fasting blood glucose concentrations, plasma lipids, changes in body weight, changes in body mass index, and change in insulin levels were checked at each study visit and at the end of the study. Treatment success, as measured by the reduction of HbA_1c, was greatest for the 7.5 g D-tagatose dose group, although the difference between the treatments was not statistically significant. For fasting glucose, only the 7.5 g dosage group exhibited reductions from baseline at the 3- and 6-month time points. Mean body weights reduced in a dose-response fashion, with the 5.0 g and the 7.5 g D-tagatose doses providing the greatest reductions. D-tagatose at dosages of 2.5 g, 5.0 g, and 7.5 g TID for six months were well tolerated by this subject population. D-tagatose at 5.0 g TID was the minimal dose required to reduce HbA_1c. D-tagatose at 7.5 g TID provided the greatest effect in most measured efficacy parameters.

DDDAS Design of Drug Interventions for the Treatment of Dyslipidemia in ApoE-/- Mice

Computational models of complex systems, such as signaling networks and biological systems, can be used to explain the behavior of such systems under various conditions. The large number of integrated processes and variables, and the nonlinearities inherent in the fundamental processes, make it difficult for scientists unassisted by computer simulations to effectively predict the consequences of a particular intervention. For this reason, computer simulation has become an important tool for generating hypotheses about the behavior of these systems that can then be tested in the laboratory and clinic. A dynamic data-driven application simulation (DDDAS) was designed by Biospherics to model complex metabolic disease pathways by testing potential binary therapies in simulations at various combinations of two points in the pathways. Since DDDAS chooses the most effective pair-wise combinations, this data-driven system allows for the implementation of real-time data to model or predict a measurement or event. By incorporating data dynamically rather than statically, the predictions and measurements become more reliable. Dyslipidemia, a common precursor to atherosclerosis, can be manifested by high triglycerides, increased apolipoprotein (Apo) B, high levels of LDL, and low levels of HDL. SPX106 and D-tagatose is a combination drug therapy composed of a carbohydrate (D-tagatose) and SPX106. D-tagatose has been studied for the treatment of diabetes for several years, and has the ability to lower blood insulin levels and to decrease glycogen formation. SPX106 is a natural substance that accelerates lipid catabolism and inhibits dyslipidemia. In apolipoprotein E knockout mice (ApoE^-/-), this drug combination has been shown to significantly lower both the amount of atherosclerosis and blood cholesterol levels. This study used 26 male ApoE^-/- mice (n=13 in each group, control and treated). The control group received the normal "Western" diet (Harlan TD88137) and the treatment group received a modified version in which the sucrose was replaced with D-tagatose and 1g of SPX106 was added for every kilogram of chow. Mice were fed the diet for 8 weeks and then sacrificed via cardiac puncture. Blood serum was analyzed for cholesterol concentration. A significant difference was observed between the control and treated groups for total cholesterol levels. FPLC separations were done on fractions from both control and treated groups. A significant difference between VLDL and HDL levels was found between the treated and control mice (p<0.05 for both). Aortas were also taken and preserved in formalin to be quantified for atherosclerosis. Aortic sinuses were frozen in OCT and sectioned using a cryostat and then quantified for atherosclerosis. Treated mice showed statistically significant reduction in atherosclerosis in the aortic arch (p<0.01), the thoracic aorta (p<0.05), and the aortic sinus (p<0.05) as well as a reduction of cholesterol (p<0.05).

Imminent cardiac risk assessment via optical intravascular biochemical analysis

Heart disease is by far the biggest killer in the United States, and type II diabetes, which affects 8% of the U.S. population, is on the rise. In many cases, the acute coronary syndrome and/or sudden cardiac death occurs without warning. Atherosclerosis has known behavioral, genetic and dietary risk factors. However, our laboratory studies with animal models and human post-mortem tissue using FT-IR microspectroscopy reveal the chemical microstructure within arteries and in the arterial walls themselves. These include spectra obtained from the aortas of ApoE-/- knockout mice on sucrose and normal diets showing lipid deposition in the former case. Also pre-aneurysm chemical images of knockout mouse aorta walls, and spectra of plaque excised from a living human patient are shown for comparison. In keeping with the theme of the SPEC 2008 conference 'Spectroscopic Diagnosis of Disease...' this paper describes the background and potential value of a new catheter-based system to provide in vivo biochemical analysis of plaque in human coronary arteries. We report the following: (1) results of FT-IR microspectroscopy on animal models of vascular disease to illustrate the localized chemical distinctions between pathological and normal tissue, (2) current diagnostic techniques used for risk assessment of patients with potential unstable coronary syndromes, and (3) the advantages and limitations of each of these techniques illustrated with patent care histories, related in the first person, by the physician coauthors. Note that the physician comments clarify the contribution of each diagnostic technique to imminent cardiac risk assessment in a clinical setting, leading to the appreciation of what localized intravascular chemical analysis can contribute as an add-on diagnostic tool. The quality of medical imaging has improved dramatically since the turn of the century. Among clinical non-invasive diagnostic tools, laboratory tests of body fluids, EKG, and physical examination are still the first line of defense. However, with the fidelity of 64-slice CT imaging, this technique has recently become an option when the patient presents with symptoms of reduced arterial flow. Single photon emission computerized tomography (SPECT) treadmill exercise testing is a standard non-invasive test for decreased perfusion of heart muscle, but is time consuming and not suited for emergent evaluation. Once the invasive clinical option of catherization is chosen, this provides the opportunity for intravascular ultrasound (IVUS) imaging. As the probe is pulled through the artery, the diameter at different parts is measurable, and monochrome contrast in the constricted area reveals the presence of tissue with a different ultrasonic response. Also, via an optical catheter with a fiber-optic conductor, the possibly of spectroscopic analysis of arterial walls is now a reality. In this case, the optical transducer is coupled to a near-infrared spectrometer. Revealing the arterial chemical health means that plaque vulnerability and imminent risk could be assessed by the physician. The classical emergency use of catherization involves a contrast agent and dynamic X-ray imaging to locate the constriction, determine its severity, and possibly perform angioplasty, and stent placement.

Effect of diets containing sucrose vs. D-tagatose in hypercholesterolemic mice

Effects of functional sweeteners on the development of the metabolic syndrome and atherosclerosis are unknown. The objective was to compare the effect of dietary carbohydrate in the form of sucrose (SUCR) to D-tagatose (TAG; an isomer of fructose currently used as a low-calorie sweetener) on body weight, blood cholesterol concentrations, hyperglycemia, and atherosclerosis in low-density lipoprotein receptor deficient (LDLr(-/-)) mice. LDLr(-/-) male and female mice were fed either standard murine diet or a diet enriched with TAG or SUCR as carbohydrate sources for 16 weeks. TAG and SUCR diets contained equivalent amounts (g/kg) of protein, fat, and carbohydrate. We measured food intake, body weight, adipocyte diameter, serum cholesterol and lipoprotein concentrations, and aortic atherosclerosis. Macrophage immunostaining and collagen content were examined in aortic root lesions. CONTROL and TAG-fed mice exhibited similar energy intake, body weights and blood glucose and insulin concentrations, but SUCR-fed mice exhibited increased energy intake and became obese and hyperglycemic. Adipocyte diameter increased in female SUCR-fed mice compared to TAG and CONTROL. Male and female SUCR-fed mice had increased serum cholesterol and triglyceride concentrations compared to TAG and CONTROL. Atherosclerosis was increased in SUCR-fed mice of both genders compared to TAG and CONTROL. Lesions from SUCR-fed mice exhibited pronounced macrophage immunostaining and reductions in collagen content compared to TAG and CONTROL mice. These results demonstrate that in comparison to sucrose, equivalent substitution of TAG as dietary carbohydrate does not result in the same extent of obesity, hyperglycemia, hyperlipidemia, and atherosclerosis.

Molecular Factor Computing for Predictive Spectroscopy

PURPOSE

The concept of molecular factor computing (MFC)-based predictive spectroscopy was demonstrated here with quantitative analysis of ethanol-in-water mixtures in a MFC-based prototype instrument.

METHODS

Molecular computing of vectors for transformation matrices enabled spectra to be represented in a desired coordinate system. New coordinate systems were selected to reduce the dimensionality of the spectral hyperspace and simplify the mechanical/electrical/computational construction of a new MFC spectrometer employing transmission MFC filters. A library search algorithm was developed to calculate the chemical constituents of the MFC filters. The prototype instrument was used to collect data from 39 ethanol-in-water mixtures (range 0-14%). For each sample, four different voltage outputs from the detector (forming two factor scores) were measured by using four different MFC filters. Twenty samples were used to calibrate the instrument and build a multivariate linear regression prediction model, and the remaining samples were used to validate the predictive ability of the model.

RESULTS

In engineering simulations, four MFC filters gave an adequate calibration model (r2 = 0.995, RMSEC = 0.229%, RMSECV = 0.339%, p = 0.05 by f test). This result is slightly better than a corresponding PCR calibration model based on corrected transmission spectra (r2 = 0.993, RMSEC = 0.359%, RMSECV = 0.551%, p = 0.05 by f test). The first actual MFC prototype gave an RMSECV = 0.735%.

CONCLUSION

MFC was a viable alternative to conventional spectrometry with the potential to be more simply implemented and more rapid and accurate.

Near Infrared Spectrometry for the Quantification of Human Dermal Absorption of Econazole Nitrate and Estradiol

PURPOSE

The purpose of this study was to demonstrate the use of near-infrared (NIR) spectrometry for the in vitro quantification of econazole nitrate (EN) and estradiol (EST) in human skin.

METHODS

NIR spectra were collected from EN and EST powders to verify the presence of NIR chromophores. One percent EN cream, a saturated solution of EN, or 0.25% EST solution was applied to human skin. NIR spectra were collected and one-point net analyte signal (NAS) multivariate calibration was used to predict the drug concentrations. NIR results were validated against known skin concentrations measured by high-pressure liquid chromatography (HPLC) analysis of solvent extracts.

RESULTS

NIR spectroscopy measured dermal absorption from saturated solutions of EN on human skin with an r2=0.990, standard error of estimation (SEE)=2.46%, and a standard error of performance (SEP)=3.55%, EN cream on skin with an r2=0.987, SEE=2.30%, and SEP=2.66%, and 0.25% solutions of EST on skin with an r2=0.987, SEE=3.30%, and SEP=5.66%. Despite low permeation amounts of both drugs through the stratum corneum into human tissue, the NIR signal-to-noise ratio was greater than three, even for the lowest concentrations.

CONCLUSION

NIR analyses paralleled the results obtained from HPLC, and thus could serve as a viable alternative for measuring the topical bioavailability/bioequivalence of different EN and EST formulations. Because these experiments were conducted in human tissue, this research suggests an all-optical in vivo method of measurement for dermal absorption could be developed.

Near-Infrared Spectrometry for the Quantification of Dermal Absorption of Econazole Nitrate and 4-Cyanophenol

PURPOSE

The purpose of this study was to demonstrate the utility of near-infrared (NIR) spectroscopy for the in vitro quantification of econazole nitrate (EN) and 4-cyanophenol (4-CP) in hairless guinea pig skin.

METHODS

NIR spectra were collected from each of the following: EN and 4-CP powders, EN and 4-CP in solution, and skin samples following topical exposure to either 4-CP in water or EN in propylene glycol and topical creams. To predict drug concentration from NIR spectra, principal component regression (PCR), interval PCR, and uninformative variable elimination PCR were each used with a leave-one-out cross-validation, and results were compared. NIR results were validated against known skin concentrations measured by high-pressure liquid chromatography (HPLC) analysis of solvent extracts.

RESULTS

NIR results matched the HPLC results for the quantification of 4-CP and EN in skin exposed to saturated solutions and topical creams with an r2 > 0.90, a standard error of estimation < 7.0%, and a standard error of performance < 8.0%.

CONCLUSION

This experiment demonstrated that NIR closely parallels results obtained from tissue extraction and HPLC analysis, proving its potential utility for the rapid and noninvasive determination of topical bioavailability/bioequivalence of EN and quantification of the model chemical 4-CP. Investigation of drugs in human skin is now justified.

Acoustic-resonance spectrometry as a process analytical technology for rapid and accurate tablet identification

This research was performed to test the hypothesis that acoustic-resonance spectrometry (ARS) is able to rapidly and accurately differentiate tablets of similar size and shape. The US Food and Drug Administration frequently orders recalls of tablets because of labeling problems (eg, the wrong tablet appears in a bottle). A high-throughput, nondestructive method of online analysis and label comparison before shipping could obviate the need for recall or disposal of a batch of mislabeled drugs, thus saving a company considerable expense and preventing a major safety risk. ARS is accurate and precise as well as inexpensive and nondestructive, and the sensor is constructed from readily available parts, suggesting utility as a process analytical technology (PAT). To test the classification ability of ARS, 5 common household tablets of similar size and shape were chosen for analysis (aspirin, ibuprofen, acetaminophen, vitamin C, and vitamin B12). The measures of successful tablet identification were intertablet distances in nonparametric multidimensional standard deviations (MSDs) greater than 3 and intratablet MSDs less than 3, as calculated from an extended bootstrap error-adjusted single sample technique. The average intertablet MSD was 65.64, while the average intratablet MSD from cross-validation was 1.91. Tablet mass (r (2) = 0.977), thickness (r (2) = 0.977), and density (r (2) = 0.900) were measured very accurately from the AR spectra, each with less than 10% error. Tablets were identified correctly with only 250 ms data collection time. These results demonstrate that ARS effectively identified and characterized the 5 types of tablets and could potentially serve as a rapid high-throughput online pharmaceutical sensor.

Wet granulation in rotary processor and fluid bed: comparison of granule and tablet properties

The aim of the present study was to investigate and compare granule and tablet properties of granules prepared by wet granulation in a rotary processor or a conventional fluid bed. For this purpose the working range of selected process variables was determined and a factorial study with 3 factors (equipment type, filler type, and liquid addition rate) and 1 covariate (fluidizing air flow rate) was performed. Two grades of calcium carbonate with different size and shape characteristics were applied, and the liquid addition and fluidizing air flow rates were investigated in the widest possible range. Dry mixtures of microcrystalline cellulose, polyvinyl povidone, calcium carbonate, and riboflavin, in a 10:5:84:1 ratio, were granulated in both types of equipment. The granulation end point was determined manually in the fluid bed and by torque measurements in the rotary processor. The filler type had a more pronounced effect on granular properties in the fluid bed, but the rotary processor showed a higher dependency on the investigated process variables. The rotary processor gave rise to more dense granules with better flow properties, but the fluid bed granules had slightly better compressional properties. Furthermore, the distribution of a low-dose drug was found to be more homogeneous in the rotary processor granules and tablets. Generally, wet granulation in a rotary processor was found to be a good alternative to conventional fluid bed granulation, especially when cohesive powders with poor flow properties or formulations with low drug content are to be granulated by a fluidizing air technique.

From vulnerable plaque to vulnerable patient: a call for new definitions and risk assessment strategies: Part II

Atherosclerotic cardiovascular disease results in >19 million deaths annually, and coronary heart disease accounts for the majority of this toll. Despite major advances in treatment of coronary heart disease patients, a large number of victims of the disease who are apparently healthy die suddenly without prior symptoms. Available screening and diagnostic methods are insufficient to identify the victims before the event occurs. The recognition of the role of the vulnerable plaque has opened new avenues of opportunity in the field of cardiovascular medicine. This consensus document concludes the following. (1) Rupture-prone plaques are not the only vulnerable plaques. All types of atherosclerotic plaques with high likelihood of thrombotic complications and rapid progression should be considered as vulnerable plaques. We propose a classification for clinical as well as pathological evaluation of vulnerable plaques. (2) Vulnerable plaques are not the only culprit factors for the development of acute coronary syndromes, myocardial infarction, and sudden cardiac death. Vulnerable blood (prone to thrombosis) and vulnerable myocardium (prone to fatal arrhythmia) play an important role in the outcome. Therefore, the term "vulnerable patient" may be more appropriate and is proposed now for the identification of subjects with high likelihood of developing cardiac events in the near future. (3) A quantitative method for cumulative risk assessment of vulnerable patients needs to be developed that may include variables based on plaque, blood, and myocardial vulnerability. In Part I of this consensus document, we cover the new definition of vulnerable plaque and its relationship with vulnerable patients. Part II of this consensus document will focus on vulnerable blood and vulnerable myocardium and provide an outline of overall risk assessment of vulnerable patients. Parts I and II are meant to provide a general consensus and overviews the new field of vulnerable patient. Recently developed assays (eg, C-reactive protein), imaging techniques (eg, CT and MRI), noninvasive electrophysiological tests (for vulnerable myocardium), and emerging catheters (to localize and characterize vulnerable plaque) in combination with future genomic and proteomic techniques will guide us in the search for vulnerable patients. It will also lead to the development and deployment of new therapies and ultimately to reduce the incidence of acute coronary syndromes and sudden cardiac death. We encourage healthcare policy makers to promote translational research for screening and treatment of vulnerable patients.

From vulnerable plaque to vulnerable patient: a call for new definitions and risk assessment strategies: Part I

Atherosclerotic cardiovascular disease results in >19 million deaths annually, and coronary heart disease accounts for the majority of this toll. Despite major advances in treatment of coronary heart disease patients, a large number of victims of the disease who are apparently healthy die suddenly without prior symptoms. Available screening and diagnostic methods are insufficient to identify the victims before the event occurs. The recognition of the role of the vulnerable plaque has opened new avenues of opportunity in the field of cardiovascular medicine. This consensus document concludes the following. (1) Rupture-prone plaques are not the only vulnerable plaques. All types of atherosclerotic plaques with high likelihood of thrombotic complications and rapid progression should be considered as vulnerable plaques. We propose a classification for clinical as well as pathological evaluation of vulnerable plaques. (2) Vulnerable plaques are not the only culprit factors for the development of acute coronary syndromes, myocardial infarction, and sudden cardiac death. Vulnerable blood (prone to thrombosis) and vulnerable myocardium (prone to fatal arrhythmia) play an important role in the outcome. Therefore, the term "vulnerable patient" may be more appropriate and is proposed now for the identification of subjects with high likelihood of developing cardiac events in the near future. (3) A quantitative method for cumulative risk assessment of vulnerable patients needs to be developed that may include variables based on plaque, blood, and myocardial vulnerability. In Part I of this consensus document, we cover the new definition of vulnerable plaque and its relationship with vulnerable patients. Part II of this consensus document focuses on vulnerable blood and vulnerable myocardium and provide an outline of overall risk assessment of vulnerable patients. Parts I and II are meant to provide a general consensus and overviews the new field of vulnerable patient. Recently developed assays (eg, C-reactive protein), imaging techniques (eg, CT and MRI), noninvasive electrophysiological tests (for vulnerable myocardium), and emerging catheters (to localize and characterize vulnerable plaque) in combination with future genomic and proteomic techniques will guide us in the search for vulnerable patients. It will also lead to the development and deployment of new therapies and ultimately to reduce the incidence of acute coronary syndromes and sudden cardiac death. We encourage healthcare policy makers to promote translational research for screening and treatment of vulnerable patients.

Near-infrared spectroscopy for the determination of testosterone in thin-film composites

More rapid, reproducible, and cost-effective methods to control product quality in the pharmaceutical industry continue to be a major emphasis, particularly with the FDA through its recent process analytical technologies (PAT) initiative. Many different methods have been used to determine the stability and content uniformity of a drug in various dosage forms; however, most of these methods include the destruction of the sample. Therefore, the development of nondestructive methods that allow the analysis of each individual dosage form has become the basis of much research. A new assay for the nondestructive determination of testosterone content in mucoadhesive bi-layer thin-film composites (TFCs) using near-infrared spectroscopy (NIR) was developed. Five sets of the circular films (n=5) with theoretical testosterone content of 0, 1, 2, 3, and 4 mg per 3/8th in. diameter disks were scanned in the near-infrared region of 1100-2500 nm to determine testosterone content. The NIR results were directly compared with those obtained using a previously developed ultraviolet assay for testosterone at 240 nm. Principal component regression (PCR) was performed to calibrate the NIR assay. This correlation produced r2=0.99 with a standard error of estimate (SEE)=0.18 mg, and a standard error of performance (SEP)=0.18 on cross validation with an equal number of samples (F test passed at P=0.05). Though the UV assay showed a slightly better r2 value, the NIR assay was much quicker, easier, and nondestructive. Therefore, the NIR assay may have significant potential for use in the quality control of pharmaceutical films containing drugs.

Near-Infrared Spectrometry of Abdominal Aortic Aneurysm in the ApoE-/- Mouse

Abdominal aortic aneurysms (AAAs) occur in 5-7% of people over age 60 in the United States. Early intervention in the disease process could have a significant impact on the incidence of complications and on patient survival, but identifying incipient aneurysms can be difficult. ApoE knockout mice develop AAAs following infusion of angiotensin II (AngII) by osmotic minipump into the subcutaneous space of mice at doses ranging from 500 to 1000 ng kg(-1) min(-1) for 7-28 days. These mice are used as models of AAA development. This study tested the hypothesis that near-IR spectrometry and PCR can determine AngII dose (SEE = 26 ng kg(-1) min(-1), SEP = 37 ng kg(-1) min(-1), r2 = 0.99) and collagen/elastin (C/E) ratio (SEE = 0.38, SEP = 0.39, r2 = 0.85) in mouse aortas.

Hyperspectral techniques in analysis of oral dosage forms

Pharmaceutical oral dosage forms are used in this paper to test the sensitivity and spatial resolution of hyperspectral imaging instruments. The first experiment tested the hypothesis that a near-infrared (IR) tunable diode-based remote sensing system is capable of monitoring degradation of hard gelatin capsules at a relatively long distance (0.5 km). Spectra from the capsules were used to differentiate among capsules exposed to an atmosphere containing 150 ppb formaldehyde for 0, 2, 4, and 8 h. Robust median-based principal component regression with Bayesian inference was employed for outlier detection. The second experiment tested the hypothesis that near-IR imaging spectrometry of tablets permits the identification and composition of multiple individual tablets to be determined simultaneously. A near-IR camera was used to collect thousands of spectra simultaneously from a field of blister-packaged tablets. The number of tablets that a typical near-IR camera can currently analyze simultaneously was estimated to be approximately 1300. The bootstrap error-adjusted single-sample technique chemometric-imaging algorithm was used to draw probability-density contour plots that revealed tablet composition. The single-capsule analysis provides an indication of how far apart the sample and instrumentation can be and still maintain adequate signal-to-noise ratio (S/N), while the multiple-tablet imaging experiment gives an indication of how many samples can be analyzed simultaneously while maintaining an adequate S/N and pixel coverage on each sample.

Detection of lipid pool, thin fibrous cap, and inflammatory cells in human aortic atherosclerotic plaques by near-infrared spectroscopy

BACKGROUND

A method is needed to identify nonstenotic, lipid-rich coronary plaques that are likely to cause acute coronary events. Near-infrared (NIR) spectroscopy can provide information on the chemical composition of tissue. We tested the hypothesis that NIR spectroscopy can identify plaque composition and features associated with plaque vulnerability in human aortic atherosclerotic plaques obtained at the time of autopsy.

METHODS AND RESULTS

A total of 199 samples from 5 human aortic specimens were analyzed by NIR spectroscopy. Features of plaque vulnerability were defined by histology as presence of lipid pool, thin fibrous cap (<65 microm by ocular micrometry), and inflammatory cell infiltration. An InfraAlyzer 500 spectrophotometer was used. Spectral absorbance values were obtained as log (1/R) data from 1100 to 2200 nm at 10-nm intervals. Principal component regression was used for analysis. An algorithm was constructed with 50% of the samples used as a reference set; blinded predictions of plaque composition were then performed on the remaining samples. NIR spectroscopy sensitivity and specificity for histological features of plaque vulnerability were 90% and 93% for lipid pool, 77% and 93% for thin cap, and 84% and 89% for inflammatory cells, respectively.

CONCLUSIONS

NIR spectroscopy can identify plaque composition and features associated with plaque vulnerability in postmortem human aortic specimens. These results support efforts to develop an NIR spectroscopy catheter system to detect vulnerable coronary plaques in living patients.

Near-infrared spectroscopy and imaging for the monitoring of powder blend homogeneity

In-process testing requirements for adequacy of mixing are established in 21 CFR 211.110(a)(3). Considering also, the U.S. Food and Drug Administration's draft guidance published in 1999 (Guidance for Industry, ANDAs: Blend Uniformity Analysis; http://www.fda.gov/cder/guidance/index.htm), the importance of when and how to perform blend uniformity analysis is obvious. Near-infrared (NIR) spectroscopy was used noninvasively, in this study, to monitor powder blend homogeneity. Powder mixtures consisting of salicylic acid and Fast-Flo lactose were blended in an 8-qt. V-Blender. Optical ports installed at six positions on the blender allowed spectral collection using fiber optics. A traditional thief probe was used to collect powder samples for ultraviolet (UV) reference analysis. The blender was stopped at preselected time points for collection of NIR and UV data. Several algorithms and sampling protocols were studied to identify an optimum methodology for blend homogeneity determination. The blending process was also monitored with an InSb imaging camera for comparison with the traditional NIR spectroscopy and UV reference data. Data analysis indicates that multiple sampling points were essential for accurate and precise estimation of mixing end points. Moreover, multiple runs of identical blends often display homogeneity at unique end points, thus demonstrating the potential advantage of monitoring every blend.

Multispectral imaging of tablets in blister packaging

This experiment tested the hypothesis that using near-infrared (IR) imaging spectrometry on tablets through blister packs permits the identification and composition of multiple individual tablets to be determined simultaneously. Aspirin was selected for this study because its breakdown mechanism is well understood. Near-IR cameras were used to collect thousands of spectra simultaneously from a field of packaged aspirin tablets. Tablets were selected by a principal component analysis selection algorithm. Graphs of the columns of the transformation matrix showed that salicylic acid and acetylsalicylic acid in the samples were modeled by the principal components. The bootstrap error-adjusted single-sample technique chemometric-imaging algorithm was used to draw probability-density contour plots that revealed tablet composition. Choice of color was used to represent constituent identity, whereas intensity represented concentration. The percentage of usable pixels in the indium antimonide (InSb) array was 99.9%. The SEP was 0.06% of the tablet mass for both water uptake and salicylic acid production. The number of tablets that a typical near-IR camera can currently analyze simultaneously was also estimated to be approximately 1300.

Mechanisms contributing to angiotensin II regulation of body weight

Previous studies in our laboratory have implicated adipose tissue as a potential site for local angiotensin II (ANG II) synthesis. However, functions of ANG II in adipose tissue and the impact of ANG II on body weight regulation are not well defined. To study the effect of ANG II on body weight, a chronic ANG II infusion model was used. In study 1, a low dose of ANG II (175 ng.kg-1.min-1) was infused into rats for 14 days. Plasma ANG II levels were not elevated after 14 days of infusion. ANG II-infused rats did not gain weight over the 14-day protocol and exhibited a lower body weight than controls on day 8. Food intake was not altered, but water intake was increased in ANG II-infused rats. Blood pressure gradually increased to significantly elevated levels by day 14. Thermal infrared imaging demonstrated an increase in abdominal surface temperature. Measurement of organ mass demonstrated site-specific reductions in white adipose tissue mass after ANG II infusion. In study 2, the dose-response relationship for ANG II infusion (200, 350, and 500 ng.kg-1.min-1) was determined. Body weight (decrease), blood pressure (increase), white adipose mass (decrease), plasma ANG II levels (increase), and plasma leptin levels (decrease) were altered in a dose-related manner after ANG II infusion. In study 3, the effect of ANG II infusion (350 ng.kg-1.min-1) was examined in rats treated with the vasodilator hydralazine. Hydralazine treatment normalized blood pressure in ANG II-infused rats. The effect of ANG II to decrease body weight was augmented in hydralazine-treated rats. These results demonstrate that low levels of ANG II infusion regulate body weight through mechanisms related to increased peripheral metabolism and independent of elevations in blood pressure.

Detection of formaldehyde-induced crosslinking in soft elastic gelatin capsules using near-infrared spectrophotometry

The purpose of this research was to monitor the migration of formaldehyde from a polyethylene glycol (PEG) fill into the gelatin shell of a soft elastic gelatin capsule (SEGC) using near-infrared (NIR) spectrophotometry. SEGCs were filled with five solutions of aqueous formaldehyde in PEG (0, 0.05, 0.10, 0.20, and 0.40 v/v%), stored at ambient conditions for 48 hr, emptied, and scanned in NIR spectrophotometer. Principal component regression (PCR) was employed to analyze the spectra of the empty capsules. Good correlation was established (r2 = 0.988) when actual concentrations of formaldehyde in the PEG fill of the capsules were regressed against the principal component (PC) values from NIR spectra of the emptied and washed capsules. The loadings of the first PC describe a baseline shift in the spectra that arises from a change in water concentration. Lower PC loadings reveal the presence of signals at 1780 and 2200 nm that are not due to water absorbance, confirming the hypothesis that chemical bonds are formed during the formaldehyde-induced crosslinking of the gelatin in SEGCs. Gelatin crosslinking, initiated by formaldehyde migration from the PEG fill into the shell of an SEGC, was detected by NIR spectrophotometry. When NIR was coupled to principal component analysis, a linear relationship was found between the NIR spectra of empty SEGCs and the amount of crosslinking induced by concentrations of formaldehyde in the original fill material.