Basics of Sterile Compounding: Sterilization Methods in Sterile Product Manufacturing.

Sterilization methods to produce sterile preparations include heat, gas, radiation, and filtration. This article focuses on heat, gas, and radiation sterilization, plus a brief introduction to bright-light sterilization. Microbiology basics and microbial death kinetics, key to understanding why these sterilization methods work, will also be briefly discussed. Filtration sterilization will be covered in a separate article.

Linear solvent strength model on porous graphitic carbon stationary phase using high temperature liquid chromatographic method for allopurinol related substances analysis.

A high-performance liquid chromatography (HPLC) method was developed for the analysis of Allopurinol and its Ph.Eur. impurities using a porous graphitic carbon (PGC) stationary phase. Retention behavior of solutes was studied across a wide temperature range (30-90 °C) and various gradient times (5-20 min). Analysis of the data revealed distinct retention mechanisms between reversed-phase and PGC phases. However, it was proved that the retention of Allopurinol and its Ph.Eur. impurities on PGC stationary phase can be effectively modeled using the linear solvent strength (LSS) theory. This allows for the utilization of LSS-based method development software to optimize methods under these conditions. By using commercial chromatographic modeling software, separation of Allopurinol and Ph.Eur. impurities was optimized within a large design space. At the optimized operating conditions (pH = 2.0, tG = 6 min, T = 60 °C), all solutes were separated within 6 min with baseline resolution. Comparison between predicted and experimentally measured chromatograms further confirmed the applicability of LSS theory in developing analytical methods for PGC-based HPLC systems. The presented approach offers a general framework for method development on PGC phases.

Deep eutectic solvents as green and sustainable diluents in headspace gas chromatography for the determination of trace level genotoxic impurities in pharmaceuticals.

Genotoxic impurities (GTIs) are potential carcinogens that need to be controlled down to ppm or lower concentration levels in pharmaceuticals under strict regulations. The static headspace gas chromatography (HS-GC) coupled with electron capture detection (ECD) is an effective approach to monitor halogenated and nitroaromatic genotoxins. Deep eutectic solvents (DESs) possess tunable physico-chemical properties and low vapor pressure for HS-GC methods. In this study, zwitterionic and non-ionic DESs have been used for the first time to develop and validate a sensitive analytical method for the analysis of 24 genotoxins at sub-ppm concentrations. Compared to non-ionic diluents, zwitterionic DESs produced exceptional analytical performance and the betaine : 7 (1,4- butane diol) DES outperformed the betaine : 5 (1,4-butane diol) DES. Limits of detection (LOD) down to the 5-ppb concentration level were achieved in DESs. Wide linear ranges spanning over 5 orders of magnitude (0.005-100 µg g-1) were obtained for most analytes with exceptional sensitivities and high precision. The method accuracy and precision were validated using 3 commercially available drug substances and excellent recoveries were obtained. This study broadens the applicability of HS-GC in the determination of less volatile GTIs by establishing DESs as viable diluent substitutes for organic solvents in routine pharmaceutical analysis.

Assessing biologic/toxicologic effects of extractables from plastic contact materials for advanced therapy manufacturing using cell painting assay and cytotoxicity screening.

Plastic components are essential in the pharmaceutical industry, encompassing container closure systems, laboratory handling equipment, and single-use systems. As part of their material qualification process, studies on interactions between plastic contact materials and process solutions or drug products are conducted. The assessment of single-use systems includes their potential impact on patient safety, product quality, and process performance. This is particularly crucial in cell and gene therapy applications since interactions with the plastic contact material may result in an adverse effect on the isolated therapeutic human cells. We utilized the cell painting assay (CPA), a non-targeted method, for profiling the morphological characteristics of U2OS human osteosarcoma cells in contact with chemicals related to plastic contact materials. Specifically, we conducted a comprehensive analysis of 45 common plastic extractables, and two extracts from single-use systems. Results of the CPA are compared with a standard cytotoxicity assay, an osteogenesis differentiation assay, and in silico toxicity predictions. The findings of this feasibility study demonstrate that the device extracts and most of the tested compounds do not evoke any measurable biological changes on the cells (induction ≤ 5%) among the 579 cell features measured at concentrations ≤ 50 µM. CPA can serve as an important assay to reveal unique information not accessible through quantitative structure-activity relationship analysis and vice versa. The results highlight the need for a combination of in vitro and in silico methods in a comprehensive assessment of single-use equipment utilized in advanced therapy medicinal products manufacturing.

A new ultrasound-assisted microextraction for elemental impurities determination in tablets by ICP-MS according to USP chapters 232 and 233.

Along with the United States Pharmacopeia (USP) chapters 232 and 233 regarding elemental impurities in pharmaceutical products, new challenges have been imposed in terms of sample preparation procedures prior to inductively coupled plasma mass spectrometry analysis, considering the matrix complexities. As so, a new microextraction procedure assisted by ultrasound using a cup-horn sonoreactor, minimal reactants, and sample was proposed and validated according to USP. The procedure was optimized with samples of milled tablets and 3 different acid mixtures (HNO3, 3HNO3:1HCl, and 9HNO3:1HF) and it was compared with microwave-assisted acid digestion. In the validation step, recoveries ranging from 85 to 120 % and RSD below 10 % were obtained for 22 analytes (except Ag and Pt) with satisfactory linearity and good sensitivity. The method was then applied for 37 samples of antidepressants, which presented trace levels of As, Ba, Cd, Co, Cr, Cu, Ni, Pb, Pd, Sn, and V.

Evaluation of a Novel LC-MS/MS Based Analytical Method for the Risk Assessment of Nitrosamines in Pharmaceutical Products and Packaging Materials.

The detection of nitrosamine impurities, particularly small dialkyl types, which are frequently known to be potent mutagenic carcinogens, in some Sartan group active pharmaceutical ingredients (APIs) and finished drug products caused global regulatory organizations to have concerns. Accordingly, Registration Holders/Applicants, API manufacturers, and their raw material suppliers are required to check the presence of nitrosamines in their products and carry out risk assessments using the quality risk management principles specified in the ICH Q9 guide. In this context, a new LC-MS/MS method has been developed and validated for the simultaneous determination of NDMA, NDEA, NMBA, NDIPA, NEIPA, NDBA, and MeNP nitrosamine compounds in API and finished products as well as in primary packaging materials, one of the risk sources. This validated method was applied to check the nitrosamine content may occur from canister, blister, printed aluminum foil, nasal spray, and eye drop packaging materials as part of the Extractables & Leachables studies arising from interactions between the product and the primary packaging. For the determination and quality control of nitrosamines in sartan group pharmaceutical products and packaging materials, the developed LC-MS/MS analytical method offers highly reliable, fast, high accuracy, good sensitivity and simultaneous detection even at low concentrations.

Pilot study: External surface contamination of gemcitabine and 5-fluorouracil on drug packaging.

INTRODUCTION: Antineoplastic drugs (ADs) are commonly used pharmaceuticals for anticancer treatments. It has previously been shown that the external surface of drug vials frequently is contaminated with ADs. More than a decade ago methods to prevent occupational exposure were introduced by using plastic coverage of the glass vials or packing vials in a secondary plastic container. The aim of the pilot study was to determine contamination levels of ADs on different parts of AD packaging of two different commercially available drug vials on the Swedish market and to investigate the occurrence of cross contamination of ADs. METHODS: Packagings of gemcitabine (GEM) and 5-fluorouracil (5-FU) were tested by wipe sampling. Five ADs; GEM, 5-FU, cyclophosphamide (CP), ifosfamide and etoposide were quantified using liquid chromatography mass spectrometry. RESULTS: AD contaminations were detected in 69% and 60% of the GEM and 5-FU packaging samples. Highest levels, up to approximately 5 µg/sample, were observed on the glass vials. The protective shrink-wrap of 5-FU vials and the plastic container of GEM were contaminated with low levels of 5-FU and GEM, respectively, and furthermore the 5-FU vials with shrink-wrap were cross-contaminated with GEM. Cross-contamination of CP and GEM was detected on 5-FU vials with plastic shrink-wrap removed. CONCLUSIONS: External contamination of ADs are still present at primary drug packagings on the Swedish market. Protection of AD vials by plastic shrink-wrap or a secondary plastic container does not remove the external contamination levels completely. The presence of cross contamination of ADs on drug packagings was also observed.

Efficient extraction of adventitious virus nucleic acid using commercially available methods.

An essential step in pharmaceutical product development is screening for contamination with adventitious agents, and there is desire to develop highly sensitive assays to detect adventitious viral nucleic acid. This study sought to examine the nucleic acid extraction efficiency of three viral candidates in relevant background matrices using four different extraction methods. Three model adventitious viruses, Minute virus of Mice, Porcine Circovirus, and Feline Leukemia Virus, were diluted within a variety of background matrices relevant to pharmaceutical production methods. Upon extraction, the nucleic acid was quantified using droplet digital PCR methods. Four nucleic acid extraction methods were assessed, including commercially available kits and manual extraction methods. Each method recovered nucleic acid post-extraction for each of the model viruses within the tested background matrices. The silica-column based method recovered a greater amount of viral nucleic acid, compared to the other methods tested. Similar trends were observed when model virus was diluted in bioreactor supernatant, which replicates industry testing conditions and provides details on which extraction methods might be used in Next Generation Sequencing and PCR methods for detecting contamination within pharmaceutical products.

On the Risk of Nitrosamine Contamination During Drug Product Blister Packaging.

Most N-Nitrosamine compounds are found to be genotoxic in several animal species. Some are classified as probable or possible human carcinogens and very low acceptable daily intake has been established such as 96 ng/day for N-nitrosodimethylamine (NDMA) and 26.5 ng/N-nitrosodiethylamine (NDEA). The pharmaceutical industry has considered all processing areas for potential formation or contamination of N-nitrosamine. One risk is the potential contamination of nitrosamine during drug product blister packaging using lidding foils containing nitrocellulose, and different approaches have been used by pharmaceutical companies to evaluate and mitigate this risk. Herein we share a perspective from IQ Consortium N-nitrosamine Working Group on some of the approaches and corresponding results. From these assessments, it was concluded that the risk of nitrosamine contamination during blister packaging is negligible. The approaches shared in this perspective can be incorporated into risk assessment for nitrosamine contamination during drug product packaging at other pharmaceutical companies.

Rapid screening of pharmaceutical products for elemental impurities by a high-resolution portable energy dispersive X-ray fluorescence spectrometer using an efficient fundamental parameter method.

In this study, a rapid screening method for elemental impurities in pharmaceutical products has been established by portable energy dispersive X-ray fluorescence (EDXRF) spectroscopy combined with the efficient fundamental parameter method. The proposed method has been used for the screening of 22 elemental impurities (i.e., Cd, Pb, As, Hg, Co, V, Ni, Tl, Au, Pd, Ir, Os, Rh, Ru, Se, Ag, Pt, Sb, Mo, Cu, Sn, and Cr) in the International Conference on Harmonization (ICH) Q3D guideline. The verification of results could meet the acceptance criteria for accuracy, precision and linearity in the United States Pharmacopoeia 〈233〉. On the other hand, the limit of quantitation of the proposed EDXRF method for the screening of 22 elemental impurities in pharmaceutical products could meet the concentration limits of each element at 10 g maximum daily intake based on the established permitted daily exposure to oral drugs in the ICH Q3D guideline. Our findings open up new possibilities in the rapid screening of pharmaceutical products for the detection of elemental impurities by EDXRF, which can be expected to provide a novel, nondestructive, high-throughput, portable, and sensitive platform for the process control of elemental impurities to ensure the quality and safety of drugs.

Residual contamination in antineoplastic drug packaging.

INTRODUCTION: The handling of antineoplastic drugs should follow strict supervision and safety rules to minimize the occupational exposure risks to professionals involved. The external surface contamination of drug vials is recognized as a health risk. So, our goal was to determine if there is residual contamination on the vials and containers surface of the antineoplastic drugs doxorubicin (DOX) and cyclophosphamide (CP). METHODS: A cross-sectional study was conducted. Samples were collected using a uniform sampling procedure on the inner surfaces of the packages/boxes and the outer surfaces of the vials. The analyzes were executed by high-performance liquid chromatography/mass spectrometry (UHPLC-MS/MS). RESULTS: A total of 209 samples were analyzed, 66 of CP and 143 of DOX. CP levels were detected in nine samples (13.63%), three were below the lower limit of quantification (LLQ) and the other six had contamination levels ranging from 1.24 to 28.04 ng/filter. DOX levels were detected in 36 samples (25.17%), two were below the LLQ and the others had levels between 1.32 and 664.84 ng/filter. The majority of samples with residual contamination were in vials (80.0%), however, boxes also showed contamination. CONCLUSIONS: The results revealed the presence of residual contamination in the vials and packages of CP and DOX drugs. Although the residues found in each sample are small, special care should be taken in the handling and disposal of the antineoplastic drugs. The use of personal protective equipment is fundamental while handling the vials and packaging of cytotoxic drugs.

Exploring three-dimensional space of extractables and leachables in volatility, hydrophobicity, and molecular weight and assessment of roles of gas and liquid chromatographic methods in their comprehensive analysis.

The three-dimensional (3D) global space of organic extractables and leachables (E&L) in volatility, hydrophobicity, and molecular weight (MW), covering the pharmaceutical container-closure system, biopharmaceutical single use equipment, and tissue-contacting medical devices, has been quantitatively explored by an extensive collection of E&L compounds from the publicly available sources. The total number of compounds collected is 776, including name, CAS number, MW, and boiling point (BP). The hydrophobicity of these compounds in logPo/w are computed by Abraham solvation parameter model, using compounds' descriptors generated by an online computational program "RMG: Solvation Tools". A "global" 3D space is built to represent the physicochemical property limits of E&L quantitatively, envisioned to cover a variety of materials extracted by different solvents. This 3D space also represents the scope and capability requirements of general-purpose chromatography-based methods to profile unknown material samples, if a limited number of analytical methods are used in a routine laboratory analysis. It is concluded from the study that the 3D space corresponding to MW of 1000 Da are: BP up to 857 °C and hydrophobicity in logPo/w between - 2.3-19. Additionally, the roles of temperature programmed GC (TPGC) and reversed-phase liquid chromatographic (RPLC) methods are quantitively and critically examined in the comprehensive analysis of the 3D space, particularly for RPLC methods in retention and resolution requirements, and it is also concluded that the current concept of analytical E&L testing strategies based on volatility needs to be challenged. Finally, this study proposes a semi-empirical method in correlation and prediction of the retention time of TPGC using Abraham solvation parameter model.

Analysis of genotoxic N-nitrosamines in active pharmaceutical ingredients and market authorized products in low abundance by means of liquid chromatography - tandem mass spectrometry.

In 2018, high levels of the IARC class IIA carcinogen N-nitrosodimethylamine (NDMA) were analytically verified in the active pharmaceutical ingredient (API) valsartan, resulting in extensive regulatory action on angiotensin-II-receptor antagonists and recall of finished drug products by the pharmaceutical industry to ensure patient safety. The root cause of contamination was the unintended reaction of common reagents utilized during drug synthesis. This lead to serious effects on drug quality and immediate regulatory action. Thus, routine analysis of drug product contents are inevitable and necessitate thoroughly performed work up procedures of the product as well as adequate validated analytical methods. The nature of N-nitrosamines (NA), ranging from small, semi-volatile compounds up to highly polar molecules, effort sophisticated requirements in terms of instrumental analysis. Up today, gas as well as liquid chromatographic devices coupled to mass spectrometers are the most widespread systems for analysis. Gas chromatographic - mass spectrometric (GC-MS) systems, obviously superior towards liquid chromatography - mass spectrometry (LC-MS) for detecting small volatile compounds like NDMA, reach their limits for broadly designed studies including polar or acidic NA. In this study, a complementary and highly sensitive approach by means of liquid chromatography - tandem mass spectrometry (LC-MS/MS) is presented, including detection of 13 NA deduced from major classes of secondary amines. Thereby, the fully validated approach was performed in accordance to ICH and European Medicines Agency (EMA) guidelines. Quantitative proof-of-concept measurements with various APIs and market authorized tablets as representative drug formulations conclude applicability for further presumably contaminated substances. The approach employs organic or inorganic extraction steps with solid phase extraction (SPE). The limit of detection for the most prominent NA, NDMA and N-diethylnitrosamine (NDEA), were both 0.025 parts-per-billion (ppb) per matrix, respectively.

Chemical Characterization and Non-targeted Analysis of Medical Device Extracts: A Review of Current Approaches, Gaps, and Emerging Practices.

The developers of medical devices evaluate the biocompatibility of their device prior to FDA's review and subsequent introduction to the market. Chemical characterization, described in ISO 10993-18:2020, can generate information for toxicological risk assessment and is an alternative approach for addressing some biocompatibility end points (e.g., systemic toxicity, genotoxicity, carcinogenicity, reproductive/developmental toxicity) that can reduce the time and cost of testing and the need for animal testing. Additionally, chemical characterization can be used to determine whether modifications to the materials and manufacturing processes alter the chemistry of a patient-contacting device to an extent that could impact device safety. Extractables testing is one approach to chemical characterization that employs combinations of non-targeted analysis, non-targeted screening, and/or targeted analysis to establish the identities and quantities of the various chemical constituents that can be released from a device. Due to the difficulty in obtaining a priori information on all the constituents in finished devices, information generation strategies in the form of analytical chemistry testing are often used. Identified and quantified extractables are then assessed using toxicological risk assessment approaches to determine if reported quantities are sufficiently low to overcome the need for further chemical analysis, biological evaluation of select end points, or risk control. For extractables studies to be useful as a screening tool, comprehensive and reliable non-targeted methods are needed. Although non-targeted methods have been adopted by many laboratories, they are laboratory-specific and require expensive analytical instruments and advanced technical expertise to perform. In this Perspective, we describe the elements of extractables studies and provide an overview of the current practices, identified gaps, and emerging practices that may be adopted on a wider scale in the future. This Perspective is outlined according to the steps of an extractables study: information gathering, extraction, extract sample processing, system selection, qualification, quantification, and identification.

A Full Evaporation Static Headspace Gas Chromatography Method with Nitrogen Phosphorous Detection for Ultrasensitive Analysis of Semi-volatile Nitrosamines in Pharmaceutical Products.

The recent detection of potent carcinogenic nitrosamine impurities in several human medicines has triggered product recalls and interrupted the supply of critical medications for hundreds of millions of patients, illuminating the need for increased testing of nitrosamines in pharmaceutical products. However, the development of analytical methods for nitrosamine detection is challenging due to high sensitivity requirements, complex matrices, and the large number and variety of samples requiring testing. Herein, we report an analytical method for the analysis of a common nitrosamine, N-nitrosodimethylamine (NDMA), in pharmaceutical products using full evaporation static headspace gas chromatography with nitrogen phosphorous detection (FE-SHSGC-NPD). This method is sensitive, specific, accurate, and precise and has the potential to serve as a universal method for testing all semi-volatile nitrosamines across different drug products. Through elimination of the detrimental headspace-liquid partition, a quantitation limit of 0.25 ppb is achieved for NDMA, a significant improvement upon traditional LC-MS methods. The extraction of nitrosamines directly from solid sample not only simplifies the sample preparation procedure but also enables the method to be used for different products as is or with minor modifications, as demonstrated by the analysis of NDMA in 10+ pharmaceutical products. The in situ nitrosation that is commonly observed in GC methods for nitrosamine analysis was completely inhibited by the addition of a small volume solvent containing pyrogallol, phosphoric acid, and isopropanol. Employing simple procedures and low-cost instrumentation, this method can be implemented in any analytical laboratory for routine nitrosamine analysis, ensuring patient safety and uninterrupted supply of critical medications. Graphical Abstract.

External contamination of antineoplastic drug vials: an occupational risk to consider.

Risk management for workers involved in the handling and preparation of cytotoxic drugs is challenging. This study aims to investigate drug contamination of the exterior surfaces of cytotoxic drug vials. Two batches of commercially available cytotoxic drugs in unprotected vials (ifosfamide, etoposide phosphate and cyclophosphamide) and plastic shrink wrap vials (doxorubicin, cytarabine and busulfan) were tested without removing the flip-off cap or the plastic wrap, and without prewashing. The results showed significant trace amounts of cytotoxic drugs on the exterior surfaces in both unprotected (eg, cyclophosphamide, ifosfamide) and protected plastic shrink wrap vials (eg, cytarabine), indicating that the secondary packaging of protected vials does not systematically prevent exposure to the handlers. These results focus on the need for guidelines to prevent cytotoxic vial contamination and safety recommendations for staff in the handling and storage of these vials.

Proceedings of the 2019 Viral Clearance Symposium, Session 1: Viral Clearance Strategies and Case Studies.

Session 1 of the 2019 Viral Clearance Symposium proposed strategies to use prior knowledge for demonstrating robust viral clearance for biotechnologically produced recombinant proteins, such as monoclonal antibodies, and introduced methods for virus reduction applicable to recombinant adeno-associated virus (rAAV) vectors. Proposals for generic virus clearance claims were made for detergent inactivation with Triton CG-110, low pH inactivation, anion-exchange membrane chromatography, and virus filtration, and acceptance of these proposals were discussed. Furthermore, the development of an ASTM standard for retrovirus removal by small virus filters was presented, and it was found that updating and refining of conditions is still warranted. The current approach for log reduction value calculation by using the lower value from duplicate runs as worst case was questioned, and a modified concept was proposed. Finally, for rAAV vectors, several options for reduction of adventitious viruses were demonstrated such as 35 nm virus filtration, detergent inactivation, heat inactivation, and anion-exchange or affinity chromatography and were found to be feasible in order to satisfy the principles of ICH Q5A.

Sports drug testing and the athletes' exposome.

Similar to the general population, elite athletes are exposed to a complex set of environmental factors including chemicals and radiation and also biological and physical stressors, which constitute an exposome that is, unlike for the general population, subjected to specific scrutiny for athletes due to applicable antidoping regulations and associated (frequent) routine doping controls. Hence, investigations into the athlete's exposome and how to distinguish between deliberate drug use and different contamination scenarios has become a central topic of antidoping research, as a delicate balance is to be managed between the vital and continually evolving developments of sensitive analytical techniques on the one hand, and the risk of the athletes' exposome potentially causing adverse analytical findings on the other.

Meeting Report: N-Nitrosamine Impurity Control Strategies in the Pharmaceutical and Biotechnology Industries.

The American Association of Pharmaceutical Scientists (AAPS) Chemistry, Manufacturing, and Control (CMC) Community hosted a virtual panel discussion on December 9, 2020, to provide a forum to discuss N-nitrosamine control strategies in the pharmaceutical and biotechnology industries. The panel included staff from the US Food and Drug Administration (FDA) and industry subject matter experts. Meeting topics included acceptable intake levels for nitrosamine impurities, definitions of "acceptable level of risk," water as a contributor in nitrosamine risk assessments, nitrosamine impurity control strategies based upon fate/purge data, early vs. late development assessment expectations, application to oncology programs developed under ICH S9, and Drug Master File (DMF) regulatory expectations. During the meeting, divergence in global health authority expectations was additionally discussed. One of the most important outputs from this AAPS panel discussion was the criticality of continued dialog between industry and health authorities to help understand actual versus perceived risks and provide pragmatic, scientifically justified solutions to ensure patients are provided with an uninterrupted supply of safe medicines based on globally harmonized requirements.

Effect of Packaging Materials and the Leached Iron on the Stability of Butorphanol Tartrate Injection.

The aim of this study was to investigate the effect of various parameters on the stability of butorphanol tartrate injection and to screen the optimal packaging material. The effect of the headspace oxygen levels, ampoule color, manufacturer, and size on the stability of butorphanol tartrate formulation were evaluated. The headspace oxygen levels controlled by nitrogen purging were found to be particularly effective in improving stability of the butorphanol formulation, especially below 2%. Although it is a photolabile drug, butorphanol tartrate was getting degraded at much higher extent in amber color ampoules in comparison to clear ampoules. The degradation by oxidation was found to be a free radical-mediated process catalyzed by the presence of iron ions leached from the amber ampoules. The ampoule manufacturers also had a significant effect on the stability of butorphanol. Two-milliliter ampoules provided a better stability of the butorphanol tartrate injection than 1mL ampoules as 2-mL ampoules had the lower headspace oxygen level at the same level of oxygen content. The oxidation mechanism of the butorphanol tartrate injection was investigated under various conditions, which include iron powder spiking, removal of excipients, exposure to oxygen/nitrogen, exposure to stainless steel and at different pH. Iron powder spiking, presence of citric acid, exposure to oxygen, exposure to stainless steel, and high pH accelerated the oxidative degradation. The effect of oxygen, iron ion and citric acid is in agreement with a metal-catalyzed oxidation mechanism called Udenfriend reaction. Based on the formulation test results, limiting headspace oxygen level, ampoule color, manufacturer, size, controlling iron ion contamination, and pH are recommended for formulation development. In conclusion, it can be suggested that this study can lead to a better understanding of the degradation mechanism of butorphanol tartrate; hence, it would contribute to the development of butorphanol tartrate injection with improved stability. Virous packaging materials have different effects on the stability of butorphanol tartrate injection, and the leached iron of packaging ampoules and stainless steel can trigger Udenfriend reaction with butorphanol tartrate and citric acid (CA), which lead to the oxydative degradation of butorphanol tartrate injection.