Analysis of betamethasone, dexamethasone and related compounds by liquid chromatography/electrospray mass spectrometry

Simultaneous Detection Method of 11 Respiratory Drug Substances Including Theobromine, Oxymetazoline, etc. in Adulterated Dietary Supplements Using Liquid Chromatography-Electrospray Ionization-Tandem Mass Spectrometry and Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry Analysis

Recently, the demand for respiratory disease-related products has surged due to the influence of coronavirus disease 2019, prompting warnings about illegal dietary supplements containing unauthorized substances. Additionally, adulterated dietary supplements are continuously detected in open markets, posing significant public health safety problem. In this study, we developed and validated an analytical method for 11 respiratory drug substances using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) and proposed optimal conditions for LC-quadrupole time-of-flight MS (LC-QTOF-MS) to determine the fragmentation patterns of each substance. This method underwent thorough validation considering specificity, linearity, limits of detection and quantification, accuracy, precision, matrix effect, stability, etc. All results met international guidelines. These validated methods were applied to 52 dietary supplements advertised for treating respiratory diseases and enhancing respiratory function, among which one sample was found to contain 313.7 mg/g of theobromine. This determination was made by comparing the product ion ratios with the standards and subsequent quantification. To re-confirm the detected substances, their fragmentation patterns were compared with those of the standards using LC-QTOF-MS. In conclusion, the mass-based information, coupled with the LC-ESI-MS/MS method development, can be successfully applied to rapidly identify 11 respiratory drug substances in illegal dietary supplements used for respiratory disease treatment. The developed simultaneous detection method contributes to public health and safety improvements.

0.2% Betamethasone Sodium Phosphate: A Multicenter, Randomized, Double-Masked Study to Compare Its Ocular Safety, Tolerability, and Efficacy to Vehicle in Cataract Surgery Subjects

Purpose

To compare the preservative-free corticosteroid 0.2% betamethasone sodium phosphate BID (SURF-201) to vehicle BID in patients undergoing routine cataract surgery.

Methods

Phase 2, multicenter, randomized (1:1 ratio), double-masked, vehicle-controlled, parallel-group study in patients scheduled for uncomplicated cataract surgery without the aid of a femtosecond laser. Subjects instilled topical medications for 16 days beginning the day before cataract surgery (Day -1), 1 dose administered at least 1 hour prior to cataract surgery (on Day 0) and 1 dose on the evening after cataract surgery, and then 2 doses administered each day through Day 15; patients were re-evaluated on Days 22 and 32 to ensure no rebound inflammation. Primary outcome was the difference in the proportion of subjects with anterior chamber cell (ACC) grade 0 between the two groups at Day 15. Secondary outcomes included pain scores and overall safety.

Results

There was a statistically significant difference (P=0.004) in the proportion of subjects in the SURF-201 treatment group with an ACC grade of 0 at Day 15 (n=22/39 [56.4%]) compared to subjects in the vehicle treatment group (n=9/43 [20.9%]). There was no statistically significant difference (P=0.528) in the proportion of subjects in the SURF-201 treatment group who had a visual analog scale pain score of 0 at Day 15 (n=35/38 [89.7%]) compared to subjects in the vehicle group (n=33/40 [82.5%]). A slightly higher incidence of adverse events occurred in subjects in the SURF-201 treatment group (n=27/40 [67.5%]) compared to the vehicle treatment group (n=23/43 [53.5%]).

Conclusion

SURF-201 is an effective topical, preservative-free corticosteroid when dosed BID for the treatment of postoperative inflammation and prevention of pain in a post-cataract population.

Coupling of NIR Spectroscopy and Chemometrics for the Quantification of Dexamethasone in Pharmaceutical Formulations

Counterfeit or substandard drugs are pharmaceutical formulations in which the active pharmaceutical ingredients (APIs) have been replaced or ingredients do not comply with the drug leaflet. With the outbreak of the COVID-19 pandemic, fraud associated with the preparation of substandard or counterfeit drugs is expected to grow, undermining health systems already weakened by the state of emergency. Analytical chemistry plays a key role in tackling this problem, and in implementing strategies that permit the recognition of uncompliant drugs. In light of this, the present work represents a feasibility study for the development of a NIR-based tool for the quantification of dexamethasone in mixtures of excipients (starch and lactose). Two different regression strategies were tested. The first, based on the coupling of NIR spectra and Partial Least Squares (PLS) provided good results (root mean square error in prediction (RMSEP) of 720 mg/kg), but the most accurate was the second, a strategy exploiting sequential preprocessing through orthogonalization (SPORT), which led (on the external set of mixtures) to an R2pred of 0.9044, and an RMSEP of 450 mg/kg. Eventually, Variable Importance in Projection (VIP) was applied to interpret the obtained results and determine which spectral regions contribute most to the SPORT model.

A Fast, Validated UPLC Method Coupled with PDA-QDa Detectors for Impurity Profiling in Betamethasone acetate and Betamethasone phosphate Injectable Suspension and Isolation, Identification, Characterization of Two Thermal Impurities

For impurity profiling of betamethasone acetate and betamethasone phosphate injectable suspensions, a quick, verified stability indicating UPLC technique incorporating the detectors PDA-QDa had been established. This method with an analysis time of 12 min could able to separate all possible degradation impurities. Two of the thermal impurities have been identified in positive mode of detection by using QDa detector and isolated by using preparative HPLC. The method works at a flow rate of 0.5 mL/min in column: Poroshell 120 EC C18 (100 × 2.1) mm, 1.9 µm, maintained temperature precisely at 40 ºC. The M/Z values in ESI positive mode for the two new degradation impurities have been identified (M+H) as 393.22 (DP1), 363.17 (DP2) and confirmed by ¹H NMR. The approach was also verified in accordance with the rules of ICH Q2 (R1). From LOQ quantity value to 150 % quantity of specified concentration (2 % for betamethasone and 0.5 % for other impurities), the technique of UPLC-PDA-QDa was proven to be linear and accurate. Precision and ruggedness results showed ˂ 5 % RSD. Accuracy results showed more than 95 % recovery from LOQ till 150 % of impurity specification. This UPLC-PDA-QDa methodology was found specific, precise, stable and robust for quantification of all possible degradation impurities. The proposed method has been transferred to quality control laboratories to access the impurity profile during product storage.

Detection of 28 Corticosteroids in Pharmaceutical and Proprietary Chinese Medicinal Products Using Liquid Chromatography-Tandem Mass Spectrometry

With their potent anti-inflammatory effects, corticosteroids are popular adulterants in illicit health products for allergies, dermatitis and pain control. Their illegal supply over the counter is also a common practice for similar conditions. Prolonged, unsupervised usage of corticosteroids often leads to severe adverse effects including Cushing syndrome, adrenal insufficiency and immunosuppression. Confirming clinical suspicion of unsupervised corticosteroid usage is challenging. Apart from evaluating the adrenal function, identifying the concerned drug is the most direct proof of its consumption. While detecting corticosteroids or their metabolites in biological specimens is convincing evidence of their usage, such approach is analytically difficult. More importantly, this approach would not be useful if the patient has stopped taking the drug for some time-a situation that is often encountered clinically. We advocate a more direct approach by measuring corticosteroids in suspicious medicinal products. In the current study, a liquid chromatography-tandem mass spectrometry method for simultaneous detection of 28 corticosteroids in pharmaceutical and proprietary Chinese medicine products was developed and validated for the purpose. The method was applied to 388 cases of suspected unsupervised corticosteroids usage. Among 1,000 products tested, corticosteroids were found in 276 of them and confirmed the clinical suspicion.

Screening for illegal addition of glucocorticoids in adulterated cosmetic products using ultra-performance liquid chromatography/tandem mass spectrometry with precursor ion scanning

RATIONALE

The screening for illegal adulteration of glucocorticoids (GCs) in cosmetics is challenging due to the vast variety of potential GCs that are present to improve the declared effects. An effective analytical method to screen illegally added GCs in cosmetics is vital to protect consumers.

METHODS

An ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) method using precursor ion scanning (PIS) acquisition mode was developed to screen GCs in cosmetics. Forty-seven GCs were investigated to identify their common product ions formed by collision-induced dissociation. Cosmetic samples spiked with GCs were extracted using solid-phase extraction.

RESULTS

Four common positive product ions, m/z 121, 135, 147, and 171, were selected for PIS analysis. Limits of detection (LODs) were established for all 47 GCs. The method was validated on spiked samples to ensure its effectiveness in terms of sensitivity and selectivity. Sixty samples were analyzed. Seven GCs were detected in six samples.

CONCLUSIONS

An effective screening method using UPLC/MS/MS with PIS acquisition mode was developed and successfully applied to screen for targeted and untargeted GCs in cosmetic samples.

Elucidation of two new corticosteroids, betamethasone dibutyrate and betamethasone tributyrate

Corticosteroids were used normally as anti-inflammatory drugs. However, in some area certain corticosteroids might be illegally used as growth promoting agent in feed, and as prohibited doping substances in game and sport for human or/and animal performance-enhancing. Synthesized structural similar corticosteroids were popular in black market because they can pass routine drug screening. In this study two new artificial synthesized corticosteroids were found in claimed hydrolyzed wheat product. Liquid chromatography coupled with high resolution mass spectrometry (HRMS, Orbitrap) was applied to separate and elucidate the corticosteroids in the sample. Two unknown peaks with optical spectra similar to corticosteroids were first screened out at the beginning, and then their accurate molecular weight (M + H+) m/z 533.29059 and m/z 603.33289 were detected by HRMS. Element formulas of unknowns were calculated by the accurate mass and isotopes abundance. Structures were proposed by their fragment ions at high energy collision dissociation (HCD, 10 eV) and compared with candidate standard compounds. The two unknowns shared similar molecular skeleton with steroid core structure and presented man made fluorine element in their molecule. As the results, the unknowns in the sample were artificial synthesized, and the sample product was not a real food. The detected corticosteroids were also synthesized as reference compounds for conformation. Two new corticosteroids named betamethasone dibutyrate and betamethasone tributyrate were found and first time reported in this work. The legality of structural similar/modified corticosteroids were blurry and their safety were unverified. The confirmed identifications of two new found corticosteroids, and their mass spectra were provided in this paper for the reference of drug detection.

A Critical Review of Analytical Methods in Pharmaceutical Matrices for Determination of Corticosteroids

Corticosteroids are a class of hormones released by the adrenal cortex, which includes glucocorticoids and mineralocorticoids. Glucocorticoids have an important role in the metabolism of carbohydrates, proteins and calcium and effective anti-inflammatory and immunosuppressive activity. Due to their intense immunomodulatory and anti-inflammatory activity, glucocorticoids are used in the treatment of various inflammatory, malignant, allergic conditions such as rhinitis, asthma, dermatological, rheumatic, ophthalmic and neurological diseases, as well as after organ transplants. They are the most widely prescribed drugs in the world. The objective of this review is to provide an overview of the analytical methods in pharmaceutical matrices for determination of corticosteroids. In this study, the predominance of liquid chromatography methods for the analysis of corticosteroids from pharmaceutical products is evident for both liquid and semisolid dosage forms as well as for solids. The same can be said for topical, oral and parenteral formulations. Methods such as spectrophotometry are also used, but given the advantages of chromatographic methods such as better selectivity and sensitivity, they have become the choice for analysis of these drugs, however, most methods still do not meet the credentials of "green chemistry."

Separation and identification of the epimeric doping agents - Dexamethasone and betamethasone in equine urine and plasma: A reversed phase chiral chromatographic approach

Chirality is one of the most important considerations when controlling doping. The epimeric corticosteroids dexamethasone and betamethasone are significantly potent and long-acting, and they are highly abused in equestrian sports. The scope of this study was to develop a simple and reliable analytical method for simultaneously identifying and separating regularly abused co-eluting corticosteroids in equine urine and plasma. In this paper, we present a simple and rapid method for the chiral separation and identification of epimeric mixtures of dexamethasone and betamethasone using a Thermo Q Exactive high resolution accurate mass spectrometer. The high resolution accurate mass spectrometer system provided extremely high sensitivity, enabling detection of each isomer at a very low concentration from complex biological matrices. Chromatographic separation was performed using amylose and cellulose chiral columns. Reversed phase media showed very good potential for providing a successful chiral resolution in LC-MS analysis. This study also focused on optimizing the mobile phase for elution strength, nature of the organic modifier, additives, and column temperature.

Mass spectrometric method for distinguishing isomers of dexamethasone via fragment mass ratio: An HRMS approach

The major challenge in identifying dexamethasone, betamethasone, and paramethasone from a mixture of these corticosteroids is difficulty in achieving an efficient separation. In this study, we aimed to develop an efficient technique to identify these co-eluting isomers based on the mass spectral patterns of them and their corresponding phase II metabolites after electrospray ionization. Fragmentation pathways in tandem mass spectrometry revealed acceptable specificity within the groups of conjugates. The method was validated using individual isomers and mixtures at various compositions. The effects of concentration and collision energies on fragmentation patterns were also studied extensively. Matrix-fortified equine urine and plasma samples were also included so that matrix effects and interferences on fragmentation ratios could be elucidated. Preliminary results using biological samples demonstrated the suitability of this analytical strategy for direct measurement from their fragmentation patterns. Possible fragmentation pathways for each isomer were proposed.

Antibacterial and anti-inflammatory drug delivery properties on cotton fabric using betamethasone-loaded mesoporous silica particles stabilized with chitosan and silicone softener

In this study, mesoporous silica particles with a hexagonal structure (SBA-15) were synthesized and modified with (3-aminopropyl) triethoxysilane, and used as a carrier for anti-inflammatory drug, betamethasone sodium phosphate. Drug-loaded silica particles were grafted on the cotton fabric surface using chitosan and polysiloxane reactive softener as a soft and safe fixing agent to develop an antibacterial cotton fabric with drug delivery properties. Cytometry assays revealed that synthesized silica have no cytotoxicity against human peripheral blood mononuclear cells. Accordingly, the produced drug-loaded nanostructures can be applied via different routes, such as wound dressing. Drug delivery profile of the treated fabrics were investigated and compared. The drug release rate followed the conventional Higuchi model. The treated cotton fabrics were tested and evaluated using scanning electron microscope images, bending length, air permeability, washing durability and anti-bacterial properties. It was found that the chitosan-/softener-treated fabrics compounded with drug-loaded silica particles have a good drug delivery performance and exhibited a powerful antibacterial activity against both Escherichia coli and Staphylococcus aureus even after five washing cycles. The produced antibacterial cotton fabric with drug delivery properties could be proposed as a suitable material for many medical and hygienic applications.

Functionalized silica nanoparticles as a carrier for Betamethasone Sodium Phosphate: Drug release study and statistical optimization of drug loading by response surface method

Mesoporous silica nanoparticles with a hexagonal structure (SBA-15) were synthesized and modified with (3-aminopropyl) triethoxysilane (APTES), and their performance as a carrier for drug delivery system was studied. Chemical structure and morphology of the synthesized and modified SBA-15 were characterized by SEM, BET, TEM, FT-IR and CHN technique. Betamethasone Sodium Phosphate (BSP) as a water soluble drug was loaded on the mesoporous silica particle for the first time. The response surface method was employed to obtain the optimum conditions for the drug/silica nanoparticle preparation, by using Design-Expert software. The effect of time, pH of preparative media, and drug/silica ratio on the drug loading efficiency was investigated by the software. The maximum loading (33.69%) was achieved under optimized condition (pH: 1.8, time: 3.54 (h) and drug/silica ratio: 1.7). The in vitro release behavior of drug loaded particles under various pH values was evaluated. Finally, the release kinetic of the drug was investigated using the Higuchi and Korsmeyer-Peppas models. Cell culture and cytotoxicity assays revealed the synthesized product doesn't have any cytotoxicity against human bladder cell line 5637. Accordingly, the produced drug-loaded nanostructures can be applied via different routes, such as implantation and topical or oral administration.

Development and Validation of Stability-indicating HPLC Method for Betamethoasone Dipropionate and Related Substances in Topical Formulation

A gradient reversed phase HPLC method was developed and validated for analysis of betamethasone dipropionate, its related substances and degradation products, using Altima C(18) column (250×4.6 mm, 5 μm) with a flow rate of 1.0 ml/min and detection wavelength of 240 nm. The mobile phase A is a mixture of water, tetrahydrofuran and acetonitrile in the ratio of 90:4:6 (v/v/v) while mobile phase B is a mixture of acetonitrile, tetrahydrofuran, water and methanol in the ratio of 74:2:4:20 (v/v/v/v). The samples were analyzed using 20 μl injection volume and the column temperature was maintained at 50°. The limit of detection and limit of quantitation were found to be 0.02 μg/ml and 0.07 μg/ml, respectively. The stability-indicating capability of method was established by forced degradation studies and method demonstrated successful separation of drug, its related substances and degradation products. The method was validated as per the International Conference on Harmonization guidelines. The developed method is linear in the range of 0.07 to 200% of specification limits established for all the known related substances; betamethasone17-propionate, betamethasone 21-propionate, betamethasone 17-propionate-21-acetate (RSD <5, 2, 1%, respectively, r(2)=09991-0.9999 for sample concentration of 100 μg/ml). The method is sensitive, specific, linear, accurate, precise and stability indicating for the quantitation of drug, its related substances and other degradation compounds.

Understanding and fighting the medicine counterfeit market

Medicine counterfeiting is a serious worldwide issue, involving networks of manufacture and distribution that are an integral part of industrialized organized crime. Despite the potentially devastating health repercussions involved, legal sanctions are often inappropriate or simply not applied. The difficulty in agreeing on a definition of counterfeiting, the huge profits made by the counterfeiters and the complexity of the market are the other main reasons for the extent of the phenomenon. Above all, international cooperation is needed to thwart the spread of counterfeiting. Moreover effort is urgently required on the legal, enforcement and scientific levels. Pharmaceutical companies and agencies have developed measures to protect the medicines and allow fast and reliable analysis of the suspect products. Several means, essentially based on chromatography and spectroscopy, are now at the disposal of the analysts to enable the distinction between genuine and counterfeit products. However the determination of the components and the use of analytical data for forensic purposes still constitute a challenge. The aim of this review article is therefore to point out the intricacy of medicine counterfeiting so that a better understanding can provide solutions to fight more efficiently against it.

Ion mobility spectrometry-mass spectrometry (IMS-MS) of small molecules: separating and assigning structures to ions

The phenomenon of ion mobility (IM), the movement/transport of charged particles under the influence of an electric field, was first observed in the early 20th Century and harnessed later in ion mobility spectrometry (IMS). There have been rapid advances in instrumental design, experimental methods, and theory together with contributions from computational chemistry and gas-phase ion chemistry, which have diversified the range of potential applications of contemporary IMS techniques. Whilst IMS-mass spectrometry (IMS-MS) has recently been recognized for having significant research/applied industrial potential and encompasses multi-/cross-disciplinary areas of science, the applications and impact from decades of research are only now beginning to be utilized for "small molecule" species. This review focuses on the application of IMS-MS to "small molecule" species typically used in drug discovery (100-500 Da) including an assessment of the limitations and possibilities of the technique. Potential future developments in instrumental design, experimental methods, and applications are addressed. The typical application of IMS-MS in relation to small molecules has been to separate species in fairly uniform molecular classes such as mixture analysis, including metabolites. Separation of similar species has historically been challenging using IMS as the resolving power, R, has been low (3-100) and the differences in collision cross-sections that could be measured have been relatively small, so instrument and method development has often focused on increasing resolving power. However, IMS-MS has a range of other potential applications that are examined in this review where it displays unique advantages, including: determination of small molecule structure from drift time, "small molecule" separation in achiral and chiral mixtures, improvement in selectivity, identification of carbohydrate isomers, metabonomics, and for understanding the size and shape of small molecules. This review provides a broad but selective overview of current literature, concentrating on IMS-MS, not solely IMS, and small molecule applications.

Analysis of counterfeit Cialis® tablets using Raman microscopy and multivariate curve resolution

Counterfeit medicines have become a serious global problem. Consequently, analytical and pharmaceutical scientists have been active in developing and applying new methodologies to detect and analyze counterfeit medicines. Vibrational spectroscopy combined with chemometric methods is becoming a popular choice in this area of research. In this study, Raman microscopy was used to collect chemical images of counterfeit tadalafil tablets and multivariate curve resolution (MCR) was used to analyze the Raman spectra and reveal the identities of the excipients and active pharmaceutical ingredients (API) in each tablet. Resolved counterfeit tablet spectra were compared to the resolved genuine tablet spectra. Both similarities and dissimilarities were revealed by the analysis in terms of the identity of the excipients, the quantity of the API, and the distribution of the components. It was concluded that Raman microscopy combined with MCR is a powerful method to detect and analyze counterfeit tablets.

Detection of synthetic glucocorticoids by liquid chromatography-tandem mass spectrometry in patients being investigated for Cushing's syndrome

Background

We report a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the detection of four commonly prescribed steroid drugs (prednisolone, dexamethasone, betamethasone and beclomethasone dipropionate) while simultaneously measuring 24-h urine free cortisol and cortisone in patients.

Methods

Two hundred and fifty microlitre aliquots of urine were spiked with internal standard and extracted with dichloromethane. The MS instrument was operated with positive electrospray and multiple reaction monitoring. Two transitions were monitored for each analyte of interest and the ratio of the intensities of the product ion fragments was established.

Results

The LC-MS/MS method for the measurement of urine free cortisol and cortisone was established. The assay was linear up to 788 nmol/L for cortisol and 777 nmol/L for cortisone, with a limit of quantitation of 5.0 nmol/L for both. Analysis time per sample was seven minutes. Transitions for four synthetic glucocorticoids were included, and they were identified based on the ratio of the intensities of product ion fragments. Analysis of 219 samples collected from 154 patients (55 male and 99 female) revealed the presence of prednisolone in five samples from three patients. Dexamethasone was detected in samples from four patients, and betamethasone was detected in one sample.

Conclusion

This is the first LC-MS/MS method in routine use to combine quantification of urinary cortisol and cortisone and detection of synthetic glucocorticoids in patients being investigated for Cushing's syndrome. Since the most common quoted cause of Cushing's syndrome is steroid treatment, this is a valuable diagnostic tool.

Use of liquid chromatography/tandem mass spectrometric molecular fingerprinting for the rapid structural identification of pharmaceutical impurities

Use of liquid chromatography/tandem mass spectrometric (LC/MS(n)) molecular fingerprinting is systematically demonstrated as a very effective tool for rapid structural elucidation of pharmaceutical impurities through a case study in which three isomers of betamethasone sodium phosphate (BSP) were rapidly identified as degradants formed due to the D-homoannular ring expansion of the steroid core structure of BSP in the solid state. The rapid structural elucidation of these degradants was achieved by matching or closely matching the UV profiles, molecular weights, and more importantly the fragmentation patterns obtained from the LC/MS(n) (n = 1 to 3) analysis of their enzyme-catalyzed hydrolytic products, respectively, with those of a D-homoannular isomer of betamethasone available in our LC/MS(n) molecular fingerprint database. This strategy of using LC/MS(n) molecular fingerprinting to obtain high-confidence structures of unknown species is then validated by structure verification through one- (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) experiments.

Determination of betamethasone and betamethasone 17-monopropionate in human plasma by liquid chromatography-positive/negative electrospray ionization tandem mass spectrometry

This study presents a high-performance liquid chromatography-positive/negative electrospray ionization tandem mass spectrometric (LC-ESI(+/-)-MS-MS) method for the determination of betamethasone (BOH) and betamethasone 17-monopropionate (B17P) in human plasma using beclomethasone dipropionate as the internal standard (I.S.). Both compounds were extracted from human plasma with ether-cyclohexane (4:1, v/v) and were separated by HPLC on a Hanbon Lichrospher C(18) column with a mobile phase of methanol-water (85:15, v/v) at a flow rate of 0.7ml/min. Calibration curves were linear over the range of 0.10-50ng/ml for BOH and 0.050-50ng/ml for B17P. The inter-run relative standard deviations were less than 14.4% for BOH and 12.3% for B17P. The intra-run relative standard deviations were less than 9.3% for BOH and 7.9% for B17P. The mean plasma extraction recovery for BOH and B17P were in the ranges of 82.7-85.9% and 83.6-85.3%, respectively. The method was successfully applied to study the pharmacokinetics of a new formulation of betamethasone phosphate/betamethasone dipropionate injection in healthy Chinese volunteers.

Efficient method development strategy for challenging separation of pharmaceutical molecules using advanced chromatographic technologies

In this paper, we describe a strategy that can be used to efficiently develop a high-performance liquid chromatography (HPLC) separation of challenging pharmaceutical molecules. This strategy involves use of advanced chromatographic technologies, such as a computer-assisted chromatographic method development tool (ChromSword) and an automated column switching system (LC Spiderling). This process significantly enhances the probability of achieving adequate separations and can be a large time saver for bench analytical scientists. In our study, the ChromSword was used for mobile phase screening and separation optimization, and the LC Spiderling was used to identify the most appropriate HPLC columns. For proof of concept, the analytes employed in this study are the structural epimers betamethylepoxide and alphamethylepoxide (also known as 16-beta methyl epoxide and 16-alpha methyl epoxide). Both of these compounds are used in the synthesis of various active pharmaceutical ingredients that are part of the steroid pharmaceutical products. While these molecules are relatively large in size and contain various polar functional groups and non-polar cyclic carbon chains, their structures differ only in the orientation of one methyl group. To our knowledge, there is no reported HPLC separation of these two molecules. A simple gradient method was quickly developed on a 5 cm YMC Hydrosphere C(18) column that separated betamethylepoxide and alphamethylepoxide in 10 min with a resolution factor of 3.0. This high resolution provided a true baseline separation even when the concentration ratio between these two epimers was 10,000:1. Although outside of the scope of this paper, stability-indicating assay and impurity profile methods for betamethylepoxide and for alphamethylepoxide have also been developed by our group based on a similar method development strategy.

Development and validation of a stability-indicating reversed-phase high performance liquid chromatography method for assay of betamethylepoxide and estimation of its related compounds

Betamethylepoxide (16beta-methyl-Delta(1,4)-pregnadiene-9beta-11beta-oxide-17alpha,21-diol-3,20-dione) is a key intermediate for the synthesis of various active pharmaceutical ingredients (APIs) of steroid compounds. A stability-indicating reversed-phase HPLC method for assay of betamethylepoxide and estimation of its related compounds has been developed and validated. This method can accurately quantitate betamethylepoxide in the presence of numerous structurally related compounds (including the alpha-epimer, known as alphamethylepoxide). This method can also adequately separate most of the impurities from each other and estimate their quantities in betamethylepoxide samples. The stability-indicating capability of this method has been demonstrated by adequate separation of the degradation products from betamethylepoxide in stress degraded and aged stability samples. The HPLC column used in the method was a 5 cm YMC Hydrosphere C(18) column (4.6 mm I.D.) and the mobile phase consisted of (A) water and (B) acetonitrile:methanol (8:25, v/v).

Theophylline does not potentiate the effects of a low dose of dexamethasone in horses with recurrent airway obstruction

REASONS FOR PERFORMING STUDY

Theophylline has been shown to have corticosteroid-sparing effects for the treatment of human asthma. A similar effect, if present in horses, would allow diminishing the dose of corticosteroids administered to equine patients with inflammatory airway diseases.

OBJECTIVES

To evaluate whether theophylline potentiates the effects of a low dose of dexamethasone when treating horses with recurrent airway obstruction (RAO).

HYPOTHESIS

Theophylline has steroid-sparing effects in horses with RAO.

METHODS

Ten mature mixed breed horses in clinical exacerbation of RAO were studied. Using an incomplete crossover design and 3 experimental periods of 7 days duration, horses were distributed randomly in 5 treatment groups; and administered dexamethasone s.i.d., at either 0.05 mg/kg bwt i.v. or per os, or 0.02 mg/kg bwt alone or combined with theophylline at 5 mg/kg bwt per os b.i.d. A fifth group was treated with theophylline alone at the above dosage. Lung function was evaluated prior to drug administration and then 3 and 7 days later.

RESULTS

Oral administration of dexamethasone alone or combined with theophylline failed to improve lung function significantly in RAO affected horses. Theophylline alone also failed to improve lung function in all treated horses. Conversely, dexamethasone administration at 0.05 mg/kg bwt i.v. resulted in a significant improvement in lung function starting on Day 3.

CONCLUSIONS AND POTENTIAL RELEVANCE

Oral theophylline for 7 days did not improve the effects of a low dose of dexamethasone for the treatment of horses with RAO.

Analysis of bufadienolides in the Chinese drug ChanSu by high-performance liquid chromatography with atmospheric pressure chemical ionization tandem mass spectrometry

The qualitative analysis of bufadienolides in the Chinese drug ChanSu was performed using high-performance liquid chromatography with atmospheric pressure chemical ionization tandem mass spectrometry (APCI-MS/MS). Bufadienolides are the major bioactive constituents of ChanSu, which is used to treat heart failure and cancer in traditional Chinese medicine. The APCI-MS fragmentation behavior of bufadienolides was studied. For bufadienolides with only hydroxyl substituents, the fragmentation was characterized by successive eliminations of H(2)O and CO molecules, and the profile of MS/MS product ions was correlated with the number of hydroxyl groups. If a C-16 acetoxyl group was present, the fragmentation of [M+H](+) ions was triggered by initial loss of 60 Da (HOAc). The elimination of CO was significant for bufadienolides with a 19-formyl group, and the 19-hydroxyl group could be characterized by the loss of 30 Da (HCHO). These fragmentation rules were applied to the identification of bufadienolides in a methanolic extract of ChanSu, which was separated on a C(18) column with gradient elution. A total of 35 bufadienolides were identified, including four new constituents. The method established here facilitated the convenient and rapid quality control of ChanSu crude drug and its pharmaceutical preparations.

Pharmaceutical counterfeiting

Pharmaceutical counterfeiting is becoming a serious problem both in developed and developing countries. This paper considers the extent of the problem and provides several examples of drugs which have been counterfeited. Additionally, the effects of counterfeit products on consumers, health care providers, drug manufacturers and governments are discussed. Several of the currently used methods of detection are described and these include near-infrared spectroscopy, Raman spectroscopy, isotopic characterization, tensiography, chromatographic and mass spectrometric approaches. Finally, anti-counterfeiting measures such as the use of holograms, tracers and taggants and electronic tracking are summarized.

Quantitative, Highly Sensitive Liquid Chromatography–Tandem Mass Spectrometry Method for Detection of Synthetic Corticosteroids

Background: Measurements of serum or urine concentrations of synthetic glucocorticoids are useful for assessing suspected iatrogenic hypothalamic-pituitary-adrenal axis suppression and Cushing syndrome. We have developed a liquid chromatography–tandem mass spectrometry (LC-MS/MS) assay for the simultaneous quantitative analysis of beclomethasone dipropionate, betamethasone, budesonide, dexamethasone, fludrocortisone, flunisolide, fluorometholone, fluticasone propionate, megestrol acetate, methylprednisolone, prednisolone, prednisone, triamcinolone, and triamcinolone acetonide.

Methods: Stable isotopes of cortisol-9,11,12,12-d4 and triamcinolone-d1 acetonide-d6 were added as internal standards to calibrators, controls, and unknown samples. After acetonitrile precipitation, these samples were extracted with methylene chloride, and the extracts were washed and dried. Reconstituted extract (15 μL) was injected on a reversed-phase column and analyzed by LC-MS/MS in positive-ion mode. Assay precision, accuracy, linearity, and sample stability were determined by use of enriched samples. Clinical validation included analysis of 8 serum and 20 urine samples from patients with undetectable cortisol concentrations and analysis of different types of tablets.

Results: Functional assay sensitivity was as low as 0.6–1.6 nmol/L for all compounds except for triamcinolone (7.6 nmol/L). Interassay CVs were 3.0–20% for concentrations of 0.6–364 nmol/L for all analytes. Recoveries of all analytes (except triamcinolone in serum) were 82–138% at 19.2–693 nmol/L. All but one of the serum and urine samples from patients who were tested because of suppressed cortisol concentrations contained at least one synthetic steroid. Tablet analysis recovered 75% of the synthetic steroids in suspected drugs.

Conclusions: LC-MS/MS allows simultaneous quantitative detection of various synthetic steroids in serum, plasma, urine, and tablets. This provides a valuable tool for evaluating the clinical effects of topical and systemic synthetic corticosteroids.