Journal of Pharmaceutical Analysis

2018, 8(1): 封3-封4.

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Abstract:

S-Nitroso-N-acetyl-L-cysteine ethyl ester (SNACET) and N-acetyl-L-cysteine ethyl ester (NACET)–Cysteine-based drug candidates with unique pharmacological profiles for oral use as NO, H2S and GSH suppliers and as antioxidants: Results and overview

Dimitrios Tsikas, Kathrin S.Schwedhelm, Andrzej Surdacki, Daniela Giustarini, Ranieri Rossi, Lea Kukoc-Modun, George Kedia, Stefan ückert

2018, 8(1): 1-9.

Abstract(120) PDF(0)

Abstract:
S-Nitrosothiols or thionitrites with the general formula RSNO are formally composed of the nitrosylcation(NO+)and a thiolate(RS-),the base of the corresponding acids RSH.The smallest S-nitrosothiol isHSNO and derives from hydrogen sulfide(HSH,H2S).The most common physiological S-nitrosothiols arederived from the amino acid L-cysteine(CysSH).Thus,the simplest S-nitrosothiol is S-nitroso-L-cysteine(CysSNO).CysSNO is a spontaneous potent donor of nitric oxide(NO)which activates soluble guanylylcyclase to form cyclic guanosine monophosphate(cGMP).This activation is associated with multiplebiological actions that include relaxation of smooth muscle cells and inhibition of platelet aggregation.Like NO,CysSNO is a short-lived species and occurs physiologically at concentrations around 1 nM inhuman blood.CysSNO can be formed from CysSH and higher oxides of NO including nitrous acid(HONO)and its anhydride(N2O3).The most characteristic feature of RSNO is the S-transnitrosation reaction bywhich the NO+group is reversibly transferred to another thiolate.By this way numerous RSNO can beformed such as the low-molecular-mass S-nitroso-N-acetyl-L-cysteine(SNAC)and S-nitroso-glutathione(GSNO),and the high-molecular-mass S-nitrosol-L-cysteine hemoglobin(HbCysSNO)present in erythrocytesand S-nitrosol-L-cysteine albumin(AlbCysSNO)present in plasma at concentrations of theorder of 200 nM.All above mentioned RSNO exert NO-related biological activity,but they must be administeredintravenously.This important drawback can be overcome by lipophilic charge-free RSNO.Thus,we prepared the ethyl ester of SNAC,the S-nitroso-N-acetyl-L-cysteine ethyl ester(SNACET),fromsynthetic N-acetyl-L-cysteine ethyl ester(NACET).Both NACET and SNACET have improved pharmacologicalfeatures over N-acetyl-L-cysteine(NAC)and S-nitroso-N-acetyl-L-cysteine(SNAC),respectively,including higher oral bioavailability.SNACET exerts NO-related activities which can be utilized in theurogenital tract and in the cardiovascular system.NACET,with high oral bioavailability,is a strong antioxidantand abundant precursor of GSH,unlike its free acid N-acetyl-L-cysteine(NAC).Here,we reviewthe chemical and pharmacological properties of SNACET and NACET as well as their analytical chemistry.We also report new results from the ingestion of S-[15N]nitroso-N-acetyl-L-cysteine ethyl ester(S15NACET)demonstrating the favorable pharmacological profile of SNACET.

Tissue-based metabolite profiling and qualitative comparison of two species of Achyranthes roots by use of UHPLC-QTOF MS and laser micro-dissection

Yogini Jaiswal, Zhitao Liang, Alan Ho, Hubiao Chen, Leonard Williams, Zhongzhen Zhao

2018, 8(1): 10-19.

Abstract(151) PDF(2)

Abstract:
Achyranthes bidentata and Achyranthes aspera are saponin and steroid rich medicinal plants, used extensively for therapeutic treatments in Traditional Chinese Medicine (TCM) and Ayurveda. A. bidentata is reported to be one of the rare and extensively exploited medicinal plant species that face the issue of being endangered. Finding qualitative substitute with identical phyto-constituents contributing to similar composition and pharmacological benefits wil help in reducing the burden of exploitation of the natural habitats of such plants. In the present study, a comparative metabolite analysis of the whole drug and specific tissues isolated by laser micro-dissection (LMD) was carried out for both the selected species, by use of ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF MS). The results of the study indicate that the cortex and the medullary ray tissues are rich in their content of steroidal and saponin con-stituents such as (25S)-inokosterone-20,22-acetonide, ginsenoside Ro, bidentatoside II and achyranthoside B. Metabolite profiling of the whole tissues of both the species indicates presence of identical constituents. Thus, it is inferred that A. bidentata and A. aspera can be used as qualitative substitutes for each other.

A liquid chromatography with tandem mass spectrometry method for quantitating total and unbound ceritinib in patient plasma and brain tumor

Xun Bao, Jianmei Wu, Nader Sanai, Jing Li

2018, 8(1): 20-26.

Abstract(130) PDF(2)

Abstract:
A rapid,sensitive,and robust reversed-phase liquid chromatography with tandem mass spectrometrymethod was developed and validated for the determination of total and unbound ceritinib,a secondgenerationALK inhibitor,in patient plasma and brain tumor tissue samples.Sample preparation involvedsimple protein precipitation with acetonitrile.Chromatographic separation was achieved on a Waters ACQUITYUPLC BEH C18 column using a 4-min gradient elution consisting of mobile phase A(0.1% formic acidinwater)andmobile phase B(0.1% formic acid in acetonitrile),at a flow rate of 0.4 mL/min.Ceritinib and theinternal standard([13C6]ceritinib)were monitored using multiple reaction monitoring mode under positiveelectrospray ionization.The lower limit of quantitation(LLOQ)was 1 nM of ceritinib in plasma.The calibrationcurve was linear over ceritinib concentration range of 1–2000 nM in plasma.The intra-and interdayprecision and accuracy were within the generally accepted criteria for bioanalytical method(<15%).The method was successfully applied to assess ceritinib brain tumor penetration,as assessed by the unbounddrug brain concentration to unbound drug plasma concentration ratio,in patients with brain tumors.

Denaturation studies on bovine serum albumin–bile salt system:Bile salt stabilizes bovine serum albumin through hydrophobicity

Karpagaraj Malarkani, Ivy Sarkar, Susithra Selvam

2018, 8(1): 27-36.

Abstract(138) PDF(1)

Abstract:
Protein denaturation is under intensive research, since it leads to neurological disorders of severe con-sequences. Avoiding denaturation and stabilizing the proteins in their native state is of great importance, especially when proteins are used as drug molecules or vaccines. It is preferred to add pharmaceutical excipients in protein formulations to avoid denaturation and thereby stabilize them. The present study aimed at using bile salts (BSs), a group of well-known drug delivery systems, for stabilization of proteins. Bovine serum albumin (BSA) was taken as the model protein, whose association with two BSs, namely sodium cholate (NaC) and sodium deoxycholate (NaDC), was studied. Denaturation studies on the pre-formed BSA-BS systems were carried out under chemical and physical denaturation conditions. Urea was used as the chemical denaturant and BSA-BS systems were subjected to various temperature conditions to understand the thermal (physical) denaturation. With the denaturation conditions prescribed here, the data obtained is informative on the association of BSA-BS systems to be hydrophobic and this effect of hydrophobicity plays an important role in stabilizing the serum albumin in its native state under both chemical and thermal denaturation.

Insight into the interaction of inhaled corticosteroids with human serum albumin:A spectroscopic-based study

Carlotta Pontremoli, Nadia Barbero, Guido Viscardi, Sonja Visentin

2018, 8(1): 37-44.

Abstract(110) PDF(1)

Abstract:
It is well known that the safety and efficacy profile of an inhaled cortocosteroid (ICS) is influenced by the pharmacokinetic properties and associated pharmacodynamic effects of the drug. Freely circulating, protein unbound, and active ICS can cause systemic adverse effects. Therefore, a detailed investigation of drug-protein interaction could be of great interest to understand the pharmacokinetic behaviour of corticosteroids and for the design of new analogues with effective pharmacological properties. In the present work, the interaction between some corticosteroids and human serum albumin (HSA) has been studied by spectroscopic approaches. UV–Vis spectroscopy confirmed that all the investigated corticos-teroids can bind to HSA forming a protein-drug complex. The intrinsic fluorescence of HSA was quenched by all the investigated drugs, which was rationalized in terms of a static quenching mechanism. The thermodynamic parameters determined by the Van't Hoff analysis of the binding constants (negativeΔH andΔS values) clearly indicate thathydrogen bonds and van der Waals forces play a major role in the binding process between albumin and betamethasone, flunisolide and prednisolone, while hydrophobic forces may play a major role in stabilizing albumin-triamcinolone complexes.

Effect of nonionic surfactants in release media on accelerated in-vitro release profile of sirolimus eluting stents with biodegradable polymeric coating

Ami Raval, Pratap Bahadur, Ankur Raval

2018, 8(1): 45-54.

Abstract(174) PDF(5)

Abstract:
It is a well-known fact that sirolimus (SRL) undergoes degradation process via hydrolysis in aqueous media, leading to incorrect assessment of drug amount and thus release characteristics of formulations. The main objective of the present study was to evaluate the effect of nonionic surfactants in media on in-vitro release profiles for sirolimus eluting stents (SES) coated with biodegradable polymeric matrix. Phosphate buffer and acetate buffer incorporating nonionic surfactants with varying concentrations were examined for adequate solubility and stability (by RP-HPLC). Good sink condition was achieved in phosphate buffer (at pH 4.0) with 1.0%Tween 20, 1.0%Brij 35%and 0.5%Brij 58. Hydrodynamic size (by DLS) and the micelle-water partition coefficient (P) with standard free energy of solubilization (?Gs°) of drug were evaluated to get some understanding about the solubilization phenomena. About 80%of drug release during the period of 48 h was achieved in optimized drug release media which was 1.0%Tween 20 in phosphate buffer pH 4.0. The obtained accelerated SRL release profile in optimized medium cor-related well with the real time in-vitro release in phosphate buffer (pH 7.4). Surface morphology changes (by SEM), changes in gravimetric weights and molecular weight change (by GPC) were examined before and after drug release to understand the drug release mechanism which explains that the polymer did not undergo degradation during the drug release.

Electrooxidation of sulfanilamide and its voltammetric determination in pharmaceutical formulation, human urine and serum on glassy carbon electrode

Bruno R.L.Ferra, Tiago Guimar?es, Demetrius Profeti, Luciene P.R.Profeti

2018, 8(1): 55-59.

Abstract(90) PDF(0)

Abstract:
For the first time, sulfanilamide (SFD) was determined in otologic solution, human urine and serum by electroanalytical techniques on glassy carbon electrode (GCE). The cyclic voltammetry (CV) experiments showed an irreversible oxidation peak at +1.06 V in 0.1 mol/L BRBS (pH = 2.0) at 50 mV/s. Different vol-tammetric scan rates (from 10 to 250 mV/s) suggested that the oxidation of SFD on the GCE was a diffusion-controlled process. Square-wave voltammetry (SWV) method under optimized conditions showed a linear response to SFD from 5.0 to 74.7μmol/L (R = 0.999) with detection and quantification limits of 0.92 and 3.10μmol/L, respectively. The developed SWV method showed better results for detection limit and linear range than the chronoamperometry method. It has been successfully applied to determine SFD concentration in pharmaceutical formulation, human urine and serum samples with recovery close to 100%.

Synthesis of curcuminoid-imprinted polymers applied to the solid-phase extraction of curcuminoids from turmeric samples

Wisanu Thongchai, Pranom Fukngoen

2018, 8(1): 60-68.

Abstract(163) PDF(2)

Abstract:
A molecular imprinting polymer technique was successfully applied to precipitation polymerization by using styrene as a functional monomer, curcuminoids as templates, acetonitrile as a porogenic solvent, benzoyl peroxide as the initiator, and ethylene glycol dimethacrylate as the crosslinker. The effects of interaction on the adsorption capacity of the molecularly imprinted polymer (MIP) and non-imprinted polymer (NIP) were investigated. A comparison of the adsorption capacity for MIP and NIP indicated that the NIP had the lowest adsorption capacity. The curcuminoid-imprinted polymer (Cur-MIP) was syn-thesized from 0.0237 mmol of styrene, 47.0 g of acetonitrile, 1.0238 mmol of ethylene glycol dimetha-crylate, 0.0325 mmol of curcuminoids, and 0.2480 mmol of benzoyl peroxide. A high-performance liquid chromatography method with fluorescence detection was developed and validated for various chro-matographic conditions for the determination of the curcuminoids in turmeric samples. The sample solution was separated using the Cur-MIP via solid-phase extraction and analyzed on a Brownlee ana-lytical C18 column (150 mm × 6 mm, 5μm) using an isocratic elution consisting of acetonitrile and 0.1%trichloroacetic acid (40:60, v/v). The flow rate was maintained at 1.5 mL/min. The fluorescence detector was set to monitor atλex = 426 nm andλem = 539 nm. The quantification limit values were found to be 16.66, 66.66, and 33.33μg/L for curcumin, demethoxycurcumin, and bisdemethoxycurcumin, respec-tively. Thus, we concluded that the Cur-MIP and high-performance liquid chromatographic-fluorescence method could be applied to selective extraction and could be used as a rapid tool for the determination of curcuminoids in medicinal herbal extracts.

Analysis of iodinated quorum sensing peptides by LC–UV/ESI ion trap mass spectrometry

Yorick Janssens, Frederick Verbeke, Nathan Debunne, Evelien Wynendaele, Kathelijne Peremans, Bart De Spiegeleer

2018, 8(1): 69-74.

Abstract(106) PDF(1)

Abstract:
Five different quorum sensing peptides (QSP) were iodinated using different iodination techniques. These iodinated peptides were analyzed using a C18 reversed phase HPLC system, applying a linear gradient of water and acetonitrile containing 0.1% (m/v) formic acid as mobile phase. Electrospray ionization (ESI) ion trap mass spectrometry was used for the identification of the modified peptides, while semi-quan-tification was performed using total ion current (TIC) spectra. Non-iodinated peptides and mono-and di-iodinated peptides (NIP, MIP and DIP respectively) were well separated and eluted in that order. De-pending on the used iodination method, iodination yields varied from low (2%) to high (57%).

2018 Vol. 8, No. 1