Phenotypic heterogeneity in family members of patients with retinitis pigmentosa

Purpose: To describe the phenotypic variations in family members of patients with retinitis pigmentosa (RP) with different modes of inheritance and to assess the ocular abnormalities in RP families. Methods: A descriptive analysis of three types of inheritance of RP was carried out, where 64 family members were examined at a tertiary eye care center, South India. They underwent comprehensive eye examination, fundus photography, fundus autofluorescence (FAF), full?field electroretinogram (FFERG), and spectral domain optical coherence tomography (SD?OCT). Analysis was performed between mild and severe forms of abnormalities to delineate retinal structural and functional defects in RP families. Results: The mean age was 38.55 ± 17.95 years. Males were 48.4%. In autosomal recessive and X?linked recessive groups, 74.2% and 77.3%, respectively, were asymptomatic, whereas in autosomal dominant group, 27.3% were asymptomatic. The proportion of the cases with abnormalities in all three groups was higher on ERG (59.6%), followed by OCT (57.5%), visual acuity (43.7%), peripheral FAF (23.5%), and macular FAF (11.8%). However, these abnormalities and the clinical pictures of the family members had no statistical difference across the three groups of inheritance. Conclusion: Structural and functional retinal alterations were noted in four out of five asymptomatic members, suggesting the need for careful screening of RP families and the pressing need for pre?test (genetic) counseling

Application progress of high performance liquid chromatography in detection of hemagglutinin content in influenza vaccine / 中国生物制品学杂志

@#At present,the most commonly used method for detecting hemagglutinin(HA)content in influenza vaccines is still single-radial immunodiffusion(SRID). However,the preparation of standards required by this method takes a long time,usually 2 ～ 3 months. Therefore,how to quantitatively analyze HA accurately has always been a difficult problem in the detection of HA content in the situation that reference products can not be obtained at the early stage of the pandemic influenza. High performance liquid chromatography(HPLC)has its own characteristics of rapidity,high sensitivity,good repeatability and high accuracy,which can rapidly determine HA content by using different separation principles and has been widely used in the detection of HA content in influenza vaccine. This paper reviewed the research progress of the application of HPLC in the determination of HA content in influenza vaccine.

Development and verification of pre-column derivatization reverse phase-high performance liquid chromatography for determination of Glycine and Histidine content in recombinant proteins / 中国生物制品学杂志

@#Objective To develop and verify a pre-column derivatization reverse phase-high performance liquid chromatography(RP-HPLC) method for determination of Glycine and Histidine content in recombinant proteins.Methods AccQ Tag-C 18(3.9 mm × 150 mm,4 μm) column was used as chromatographic column,6-aminoquinolyl-N-hydroxysccinimidyl carbamate(AQC) was used as pre-column derivatization reagent,while α-aminobutyric acid as internal standard.AccQTag Eluent A solution,acetonitrile solution and high-purity water were used as mobile phases.The UV detection wavelength was 248 nm,injection volume was 10 μL,flow rate was 1.0 mL/min,and column temperature was 37 ℃.The contents of Glycine and Histidine in samples were determined by the internal standard method,and the specificity,linearity,detection limit,quantitative limit,precision,accuracy and stability of the method were verified.Results The developed method effectively separated Glycine,Histidine and internal standard α-aminobutyric acid with high specificity.The standard curves of Glycine in the range of 2.25～11.25 μg/mL and Histidine in the range of 72.85～364.24 μg/mL showed good linearity,each correlation coefficient(R~2) 0.99.The detection limits were 2.25 μg/mL for Glycine and 18.21 μg/mL for Histidine.The quantitative limits were 4.69 μg/mL for Glycine and 32.86 μg/mL for Histidine.The relative standard deviation(RSD) of 6 replicates with the same concentration of Glycine and Histidine were 4.6% and 5.0%,and the RSD of recovery rate in intermediate precision test was 6.9% and 2.0%,respectively.The content of Glycine was close to the quantitative limit,and the average recoveries of high,medium and low concentrations of samples were within 75.9%～111.7%;The recoveries of Histidine ranged from 88.9% to 97.3%.The RSD of Glycine content and Histidine content was 7.7% and 3.3% respectively at 0,12,18,24,30 and 48 h in the same sample.Conclusion The pre-column derivatization RP-HPLC method has accurate and reliable results with high precision,which might be used for quality control of Glycine and Histidine content in recombinant proteins.

Baicalin modulates let-7i-3p/PI3K/Akt/NF-KB signaling axis to reduce NLRP3 inflammasome activation in fibroblast like synoviocytes of rheumatoid arthritis / 中国药理学通报

Aim To study the effect of baicalin on the activation of NLRP3 inflammasomes in human fibroblast like synoviocytes of rheumatoid arthritis ( HFLS-RA) and its mechanism. Methods To confirm that baicalin alleviated the activation of NLRP3 inflammasome in HFLS-RA, immunofluorescence was used to observe the expression of NLRP3 before and after baicalin treatment. Western blot was used to detect the protein expression of p-PI3K, p-Akt, NF-κB p65, NL-RP3, ASC and caspase-1 after baicalin treatment for 48 h, and ELISA was employed to detect the contents of IL-1 and IL-18 in the supernatents. In order to explore the mechanism of baicalin alleviating the activation of NLRP3 inflammasome, double luciferin and Westen blot analysis were applied to verify the corresponding relationship between let-7i-3p and PIK3CA. RT-qPCR was utilized to determine the expression of let-7i-3p and PI3K before and after baicalin intervention. let-7i-3p interference was used to verify whether baicalin mitigated the activation of enhanced NLRP3 inflammasomes. Results Baicalin (50, 100 mg · L

Development and validation of reverse phase-high performance liquid chromatography for determination of residual N-hydroxy succinimide content in semaglutide / 中国生物制品学杂志

@#Abstract： Objective To develop and validate a reverse phase⁃high performance liquid chromatography（RP⁃HPLC） method for determination of residual N⁃hydroxy succinimide（NHS）content in semaglutide. Methods A RP⁃HPLC method was developed based on the screening of chromatographic column and optimization of mobile phase（phosphate concentration and the ratio of acetonitrile），validated for specificity，suitability，accuracy，reproducibility and stability， and determined for linear range，limit of quantitation（LOQ）and limit of detection（LOD）. The NHS contents in three batches of semaglutide were determined by the developed method. Results The optimal condition for RP⁃HPLC was as follows：CAPCELL PAK ADME column（4. 6 mm × 150 mm，3 μm）was adopted，serving 0. 05 mol／L potassium dihy⁃ drogen phosphate solution⁃acetonitrile（98∶2）as mobile phase A，and 70% acetonitrile as mobile phase B with gradient elution（0 min，0% B；10 min，0% B；19 min，90% B；19. 1 min，0% B；25 min，0% B）at a flow rate of 0. 8 mL／min. The detection wave length was set at 260 nm，while the column temperature was 30 ℃. The developed method showed good specificity and systemic suitability，of which the linear range was 0. 2 ~ 3. 0 μg／mL（R2 = 1. 000 0），while the LOD and LOQ were 4. 8 and 9. 6 ng respectively. The RSD of recovery rates of NHS samples at three concentrations was 0. 58%， indicating a high accuracy. The RSD of NHS contents in six test samples was 0. 16%，indicating a high reproducibility. The RSD of peak areas of NHS after storage at room temperature for 0，4，8，12，16，20 and 24 h was 0. 34%，indicating a high stability. No NHS was detected in three batches of semaglutide by the developed method. Conclusion The developed RP⁃HPLC method is simple and sensitive，which may be used for the determination of NHS content in semaglutide.

Inhibition of photoreceptor apoptosis in mice with retinitis pigmentosa through NF-κB/NLRP3 pathway suppression with Lycium barbarum polysaccharide / 数字中医药（英文）

Objective@# To explore whether Lycium barbarum polysaccharide (LBP) can reduce the apoptosis of retinal photoreceptor cells in retinitis pigmentosa (RP) mice by inhibiting nuclear factor-kappa B (NF-κB)/NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) signaling pathway. @*Methods@# (i) In vitro experiments, mouse retinal ganglion cells (661W cells) were divided into normal, model, LBP low-dose (LBP-L, 40 mg/L), LBP middle-dose (LBP-M, 80 mg/L), LBP high-dose (LBP-H, 160 mg/L), and positive drug control (NLRP3 inhibitor, 160 mg/L) groups. And the 661W cells were exposed to varying concentrations of H2O2 ranging from 50 to 400 μmol/L to determine the optimal concentration for inducing apoptosis (200 μmol/L). Then the cell viability was assessed using Cell Counting Kit-8 (CCK-8), while the apoptosis rate was detected by flow cytometry; the expression of NLRP3 was detected by immunofluorescence; and the expression of apoptosis markers was detected by enzyme-linked immunosorbent assay (ELISA) and Western blot (WB). (ii) In vivo assays were carried out with the use of C57/BL6 and Rd10 mice. The animal experimental groups were divided into normal, model, LBP-L, LBP-M, LBP-H, and NLRP3 inhibitor groups, in which the normal group was C57/BL6 mice and the other groups were Rd10 mice. Ten mice were included in each group, and the corresponding drugs were administered intragastrically for a duration of four weeks. NF-κB/NLRP3 pathway and the expression of apoptosis markers were observed by electroretinogram, histopathological examination, and WB to assess the effects of LBP on retinal photoreceptor cell apoptosis.@*Results@#(i) In vitro experiments, compared with the normal group, the apoptosis rate of 661W cells in model group was significantly increased (P < 0.01), and the expression levels of key proteins of NF-κB/NLRP pathway, such as NLRP3, NF-κB, p-NF-κB, and pro-apoptotic protein caspase-3, were up-regulated (P < 0.01). The rate of Bax/Bcl-2 was increased (P < 0.01), and the concentrations of interleukin (IL)-1β and tumor necrosis factor (TNF)-α were significantly increased (P < 0.01). Compared with the model group, high dose of LBP decreased the apoptosis rate of 661W cells (P < 0.01), and down-regulated the expression levelsof the key proteins of NF-κB/NLRP3 pathway, including NF-κB, NLRP3, p-NF-κB, and caspase-3 (P < 0.01). The rate of Bax/Bcl-2 was decreased (P < 0.01), and the concentrations of IL-1β and TNF-α were decreased (P < 0.01). (ii) In vivo experiments, high dose of LBP significantly increased morphological changes in the outer nuclear layer (ONL) thickness of Rd10 mice, as well as functional changes in the amplitudes of the a-wave and b-wave (P < 0.01), which also down-regulated the expression levels of NF-κB (P < 0.05), NLRP3, p-NF-κB, and caspase-3 (P < 0.01), reduced the Bax/Bcl-2 rate (P < 0.01), and decreased the concentrations of IL-1β (P < 0.01) and TNF-α (P < 0.05). @*Conclusion@#LBP could improve both retinal morphology and function, providing protection to photoreceptors from apoptosis through the inhibition of the NF-κB/NLRP3 pathway.

The optimization of PpSP15 purification from salivary glands in Iranian wild Phlebotomus papatasi (Diptera Psychodidae)

Background & objectives: Sand fly saliva contains proteins that modulate the host immune system and it plays an important role in both blood feeding and the outcome of Leishmania infections. The profile of the salivary proteins was examined and analyzed from an endemic focus of zoonotic cutaneous leishmaniasis by wild P. papatasi to find local and suitable antigens as potential proteins for developing Leishmania vaccine alongside the development of a new extraction technique. Methods: Specimens were caught from Bojnord, using funnel and CDC traps. Different methods of protein extraction were employed and a new technique was developed. The proteins were extracted from the salivary glands tissues with a lysis buffer. Purification was performed using RP-HPLC, with a linear gradient protocol from 0-60 % of acetonitrile. PpSP15 was characterized by SDS-PAGE. Results: The concentration of extracted protein content was 0.5 and 0.03 ?g/?l in chemical and physical methods, respectively. PpSP15 was isolated at a weight of 15kDa in 80–85 min of run time. SDS-PAGE was able to characterize PpSP15. The crude extract of the chemical method, revealed 15 separated bands, ranging from 11–100 KDa. Tajima D index was positive. Interpretation & conclusion: PpSP15 was characterized from Iranian specimens; it is a very highly hydrophobic protein of salivary glands among SP15- like proteins. The chemical method of extraction was found to be more effective than physical methods (P < 0.05). For developing a vaccine against leishmaniasis, depending on the location, choosing suitable proteins should be considered and an efficient extraction method should be used.

Optimization of HPLC method using central composite design for estimation of Torsemide and Eplerenone in tablet dosage form

Abstract A simple, precise, accurate and robust high performance liquid chromatographic method has been developed for simultaneous estimation of Torsemide and Eplerenone in tablet dosage form. Design of experiment was applied for multivariate optimization of the experimental conditions of RP-HPLC method. A Central composite design was used to study the response surface methodology and to analyse in detail the effects of these independent factors on responses. Total eleven experiments along with 3 center points were performed. Two factors were selected to design the matrix, one factor is variation in ratio of Acetonitrile and the second factor is flow rate (mL/min). Optimization in chromatographic conditions was achieved by applying Central composite design. The optimized and predicted data from contour diagram comprised mobile phase (acetonitrile, water and methanol in the ratio of 50: 30: 20 v/v/v respectively), at a flow rate of 1.0 ml/min and at ambient column temperature. Using these optimum conditions baseline separation of both drugs with good resolution and run time of less than 5 minutes were achieved. The optimized assay conditions were validated as per the ICH guidelines (2005). Hence, the results showed that the Quality by design approach could successfully optimize RP-HPLC method for simultaneous estimation of Torsemide and Eplerenone.

Triagem biológica de inibidores de sirtuína 2 (TcSir2rp1) candidatos a antichagásicos / Biological screening of sirtuin 2 inhibitors (TcSir2rp1) antichagasic candidates

A doença de Chagas é causada pelo Trypanosoma cruzi, e atualmente, acomete entre 6 a 7 milhões de pessoas em todo o mundo. A quimioterapia disponível para seu o tratamento se baseia apenas em dois fármacos, nifurtimox e benznidazol, com mais de 50 anos de descoberto. Estes fármacos apresentam eficácia limitada, pois são pouco efetivos na fase crônica e apresentam alta toxicidade, resultando em efeitos adversos graves. Esse panorama mostra a necessidade de novas abordagens terapêuticas contra essa doença. Nesse sentido, a inibição de vias bioquímicas essencias para o parasita se mostram como uma boa sugestão para identificação de compostos promissores candidatos a novos agentes quimioterápicos. A sirtuína 2 (Sir2) são enzimas reguladoras que participam de mecanismos epigenéticos em tripanossomatídeos, e no T. cruzi possuem um papel fundamental em todos os seus estágios evolutivos, devido a este fato, se apresentam como um alvo promissor na busca por novos fármacos contra a doença de Chagas. Neste sentido propomos a busca de inibidores da Sir2 proteína 1 do T. cruzi (TcSir2rp1) que é geneticamente validada como alvo farmacológico, por meio da estratégia de triagem biológica. Realizou-se a expressão da enzima recombinante por biologia molecular em um sistema de transformação utilizando cepa de Escherichia coli Artic Express (DE3). Foi feita a purificação e a confirmação da obtenção da proteína recombinante se deu por gel SDS-PAGE. Após a obtenção da enzima os parâmetros cinéticos foram determinados por experimentos de fluorimetria. A triagem foi realizada para um conjunto de 82 compostos, previamente sintetizados pelo nosso grupo de pesquisa, como inibidores da TcSir2p1 em dose única de 100 µM. Os ensaios foram realizados em triplicata e em experimentos independentes. Dentre os 82 compostos testados, 20 apresentaram inibições maior que 50% contra a enzima TcSir2rp1, na dose de 100 µM. Dentre estes, se destacaram 3 compostos derivados de chalconas, para os quais foi determinada a potência. O composto 1 foi o que mais potente, apresentando valor de IC50 de 11,65 µM, já os compostos 3 e 5 foram menos potentes (IC50= 38,50 µM e 19,85 µM, respectivamente). Diante dos resultados obtidos, pode-se concluir que a estratégia de triagem biológica é promissora na identificação de inibidores da TcSir2p1 candidatos a agentes anti- T. cruzi

Chagas disease is caused by Trypanosoma cruzi, and currently affects 6 to 7 million people worldwide. The chemotherapy available for its treatment is based on only two drugs, nifurtimox and benznidazole, with more than 50 years of discovery. These drugs have limited efficacy, as they are ineffective in the chronic phase and have high toxicity, resulting in serious adverse effects. This panorama shows the need for new therapeutic approaches against this disease. In this sense, the inhibition of essential biochemical pathways for the parasite proves to be a good suggestion for the identification of promising compounds candidates for new chemotherapeutic agents. Sirtuin 2 (Sir2) are regulatory enzymes that participate in epigenetic mechanisms in trypanosomatids, and in T. cruzi they have a fundamental role in all their evolutionary stages, due to this fact, they present themselves as a promising target in the search for new drugs against Chagas disease. In this sense, we propose the search for inhibitors of Sir2 protein 1 of T. cruzi (TcSir2rp1) which is genetically validated as a pharmacological target, through the biological screening strategy. The expression of the recombinant enzyme was performed by molecular biology in a transformation system using strain of Escherichia coli Artic Express (DE3). Purification was performed and confirmation of obtaining the recombinant protein was performed by SDS-PAGE gel. After obtaining the enzyme, the kinetic parameters were determined by fluorimetry experiments. Screening was performed for a set of 82 compounds, previously synthesized by our research group, as TcSir2p1 inhibitors in a single dose of 100 µM. Assays were performed in triplicate and in independent experiments. Among the 82 compounds tested, 20 showed inhibitions greater than 50% against the enzyme TcSir2rp1, at a dose of 100 µM. Among these, 3 compounds derived from chalcones stood out, for which the potency was determined. Compound 1 was the most potent, with an IC50 value of 11.65 µM, while compounds 3 and 5 were less potent (IC50= 38.50 µM and 19.88 µM, respectively). In view of the results obtained, it can be concluded that the biological screening strategy is promising in the identification of TcSir2p1 inhibitors candidates for anti-T. cruzi agents

Analysis of the protein profile of the venoms of snakes Bothrops asper, Bothrocophias myersi and Crotalus durissus from the Colombian Andean Region obtained by RP-HPLC / Análisis del perfil proteico de los venenos de Bothrops asper, Bothrocophias myersi y Crotalus durissus serpientes de la Región Andina en Colombia obtenidos por RP-HPLC

ABSTRACT Snake venoms comprise a highly complex mixture of proteins, and there is also a high interspecific and intraspecific variability in their composition, even in the same region. Our aim was to compare the composition of the venoms of Bothrocophias myersi, Crotalus durissus, and Bothrops asper, snakes from the Colombian Andean region by Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC). The venoms were given to the research group under an agreement with Fundación Zoológica de Cali. The venoms pool was obtained by manual extraction, lyophilized and frozen. The venom protein was quantified by direct measurement with Nanodrop® 280 nm. The protein composition was established by RP-HPLC, using a Lichosper 100 RP, C18 column (250X4 mm) with a pore size of 5-m, as well as by Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE). The highest quantity of protein was found in the venom of B. myersi (108.6 mg/ mL) followed by C. durissus (78.1 mg/mL) and B. asper (74.1 mg/mL). All venoms showed bands of 15 and 50 KDa by using SDS-PAGE. B. myersi venom chromatogram exhibited 16 peaks by RP-HPLC. We conclude that the composition of the three venoms is quite similar, being phospholipase A2 the common protein therein, and together with metalloproteinases they were the most abundant protein families in the venom of B. myersi. SDS-PAGE and RP-HPLC techniques allow a first approach to the profile of the venoms, which in turn could clarify the clinical syndrome produced.

RESUMEN Los venenos de las serpientes comprenden una mezcla compleja de proteínas, y existe una alta variabilidad interespecífica e intra-específica en su composición, incluso en la misma región. Nuestro objetivo fue comparar la composición de los venenos de Bothrocophias myersi, Crotalus durissus y Bothrops asper de la región andina de Colombia, mediante cromatografía líquida de alta eficiencia en fase reversa (RP-HPLC). Los venenos fueron entregados al grupo de investigación mediante un convenio con la Fundación Zoológica de Cali. El pool de venenos fue obtenido por extracción manual, liofilizado y congelado. La proteína de los venenos fue cuantificada por Absorbancia 280nm por medición directa con Nanodrop®. La composición proteica se estableció por RP-HPLC, utilizando una columna Lichosper 100 RP, C18 (250X4 mm) con un tamaño de poro de 5-jm, así como por electroforesis en gel dodecil sulfato de sodio-poliacrilamida (SDS-PAGE). La mayor cantidad de proteínas se encontró en el veneno de B. myersi (108.6 mg/mL), seguido de C. durissus (78.1 mg/mL) y B. asper (74.1 mg/mL). Todos los venenos mostraron bandas de 15 y 50 KDa por SDS-PAGE. El cromatograma de B. myersi exhibió 16 picos por RP-HPLC. Concluimos que la composición de los tres venenos es bastante similar, siendo la fosfolipasa A2 la proteína común en estos y junto con las metaloproteinasas fueron las familias de proteínas más abundantes en el veneno de B. myersi. Las técnicas de SDS-PAGE y el RP-HPLC permiten un primer acercamiento al perfil de los venenos, lo que a su vez podría contribuir a esclarecer el síndrome clínico producido.

Structural Characteristics and Biological Functions of Proteasome Regulatory Particles / 中国生物化学与分子生物学报

Proteasome regulatory particles(RPs) play a vital role in many essential signaling pathways for the regulation of protein degradation and maintenance of cell homeostasis. The mechanism of eukaryotic proteasomes in cancer treatment and drug development has attracted widespread attention. Currently, three proteasome inhibitors are already in use in clinical treatments. There is continuous in-depth research on proteasome structures as well as functions using crystallography and cryo-electron microscopy. Recently, the atomic structure of three types of RPs has been resolved. Type 1 is conservative RP 19S (PA700). Type 2 is the 11S RP PA28 (PA28α, PA28β, PA28γ) and PA26. Type 3 is a conservative Blm10/PA200 proteasome RP. The Type 1 proteasome RP carries out protein degradation activity in an ATP-dependent manner, types 2 and 3 function in an ATP-independent manner. By studying the structure and function of three different types of proteasome RPs, the mechanism of proteasome activity was clarified and the development of inhibitors based on the structure was promoted. Based on the structural biology research of proteasome RPs, this article systematically summarizes the structural biological characteristics of the three types of proteins and the research progress of their mechanisms of regulation of different cellular processes. This will increase our knowledge about proteasome research developments and will provide important reference information for drug design in cancer treatment.

Determination of three constituents in compound ketoconazole ointment by RP-HPLC / 药学实践杂志

Objective To establish a RP-HPLC method for determination of ketoconazole, mupirocin and mometasone furoate in compound ketoconazole ointment. Methods RP-HPLC was conducted on a Intersil ODS-3 column (250 mm×4.6 mm, 5 μm), with methanol-PBS with pH 5.5 (65:35) as the mobile phase and the column temperature was 45 ℃. The flow rate was 1.0 ml/min, and the detection wavelength was 248 nm. Results The methodological verification showed that ketoconazole, mupirocin and mometasone furoate had a good linearity (r≥0.9995). The inter/intra-day precisions were less than 3.0%, The recovery rates were between 90% and 108%. The stability and repeatability of RSD were also less than 3.0%, which met the requirements of method validation. The contents of the three components in three batches were determined by the new method. Conclusion The method is simple and reliable. It can provide a basis for the quality control of compound ketoconazole ointment and lay a foundation for its quality standard research.

Development and validation of RP-HPLC method for simultaneous determination of lamivudine, stavudine, and zidovudine in perfusate samples: Application to the Single-Pass Intestinal Perfusion (SPIP) studies

A reversed-phase high performance liquid chromatography (RP-HPLC) method with ultraviolet detection was developed and validated for the simultaneous quantification of antiretroviral drugs lamivudine (3TC), stavudine (d4T), and zidovudine (AZT) in perfusate samples obtained from the Single-Pass Intestinal Perfusion studies. The chromatographic analysis was performed using a Gemini C18 column and didanosine as internal standard (IS). The following parameters were considered for the validation procedure: system suitability, accuracy, precision, linearity and selectivity. The limits of detection were 0.32 µg/mL for 3TC, 0.11 µg/mL for d4T and 0.45 µg/mL for AZT and the limits of quantification were 1.06 µg/mL for 3TC, 0.38 µg/mL for d4T and 1.51 µg/mL for AZT. Repeatability and intermediate precision ranged from 1.05 to 1.31 and 1.50 to 1.87, respectively, and are expressed as percent of relative standard deviation (RSD). Based on these results, the developed and validated RP-HPLC method can be used for simultaneous determination of 3TC, d4T, and AZT in perfusate samples. Furthermore, this method is simple and adequate for measurements of the antiretroviral drugs in the same sample, since those compounds are mostly co-administered. Besides, this work can be used as an initial base for the development of similar methods in the same conditions presented in our study.

Development And Validation Of Stability-Indicating Rp-Uplc Method For The Simultaneous Estimation Of Tezacaftor And Ivacaftor In Formulations

Objective: Aim of the present research work was to develop a sensitive, rapid and accurate, stability-indicating RP-UPLC method for the simultaneous estimation of tezacaftor and ivacaftor in formulations. Methods: The chromatographic separation of the mixture of tezacaftor and ivacaftor was attained in isocratic method utilizing a mobile phase of 0.1 % orthophosphoric acid and acetonitrile in the proportion of 50:50%v/v utilizing a HSS C18 column which has dimensions of 100×2.1 mm, 1.7 m particle size and the flow rate of 0.3 ml/min. The detection system was monitored at 292 nm wavelength maximum with 1.5 ml injection volume. The present method was validated as per the guidelines given by the ICH for specificity, accuracy, sensitivity, linearity and precision. Results: The retaining time for tezacaftor and ivacaftor were achieved at 1.071 min and 0.530 min, respectively. Tezacaftor, ivacaftor and their combined drug formulation were exposed to thermal, acidic, oxidative, photolytic, and alkaline conditions. The developed method was highly sensitive, rapid, precise and accurate than the earlier reported methods. The total run time was decreased to 2.0 min; hence, the technique was more precise and economical. Stability studies directed for the suitability of the technique for degradation studies of tezacaftor and ivacaftor. Conclusion: The projected method can be utilized for routine analysis in the quality control department in pharmaceutical trades.

Rp-Hplc Method Development And Validation For The Combination Of Imiquimod And Salicylic Acid

Objective: The present study was undertaken to develop and validate an RP-HPLC method for the combination of imiquimod and salicylic acid Methods: The method was carried out on Nucleodur C18 (250 mm × 4.6 mm I.D., 5 ????m) using low-pressure gradient elution mode. The mobile phase was used as 30M potassium dihydrogen phosphate and acetonitrile (45:55) pH 6.5 adjusted using ortho-phosphoric acid. The concentration of solvents was 1-20 µg/ml and the volume of injection was 20 mcl with the flow rate of 1.0 ml/min. The absorption maxima of salicylic acid and imiquimod were found 234 nm and 226 nm, respectively. Results: The method was validated and showed the linearity greater than 0.99% and with precision (RSD%<1). The limit of detection (LOD) and limit of quantification (LOQ) of salicylic acid was found to be 0.09756 µg/ml and 0.2956 µg/ml, respectively, and imiquimod was found to be 0.044031 µg/ml and 0.13334 µg/ml, respectively. Conclusion: The method developed in the present study was found to be sensitive, specific, and can be applied for the simultaneous estimation of imiquimod and salicylic acid.

Simultaneous detection and quantification of bronchodilators in pure form and from in-vitro drug release of a novel combinational formulation

The analytical method was developed and validated for the quantification of salbutamol sulfate (SS) and ipratropiumbromide (IPB) in accordance with the International Council for Harmonization guidelines in its pure form. Thechromatographic partition was completed utilizing a blend of acetonitrile:phosphate buffer (30:70 v/v) with the pHscale adjusted to 3.0 using o-phosphoric acid at a flow rate of 1 ml/minute in Luna C-18(2)(150 × 4.6 mm i.d., 5 μm)column. The wavelength for detection was fixed at 212 nm. The SS and IPB showed a standard linearity curve in therange of 2–12 µg/ml, with retention time at 2.4 and 3.8 minutes, respectively. The developed method was reported tobe specific, linear (r2 ≥ 0.999), precise at intraday and interday levels (% relative standard deviation < 2.0%), accurate(% recovery: 96.02%–103.62%), and robust. The limit of detection and limit of quantification for SS was found to be0.42 and 1.26 µg/ml, while that of IPB was 0.44 and 1.34 µg/ml, respectively. Additionally, the developed method waseffectively applied in quantifying SS and IPB from its pure, commercial, and in-house prepared transdermal system tounderstanding the in-vitro drug release pattern from patches.

Development And Evaluation Of Novel Estimation Techniques For In Vitro Dissolution Study And Validation Protocol For Escitalopram As Antidepressant Drug And Their Formulation

Objective: To develop and validate the RP-HPLC method and in vitro dissolution study for escitalopram as antidepressant drug and their formulation. Methods: The chromatographic separation was done by using a C-18, 150 mm column and a mobile phase consisting of phosphate buffer (40%) and acetonitrile HPLC grade (60%). Detection was carried out at 211 nm with a flow rate of 1 ml/min with an injection of 20 μl. The method was validated with different parameters such as linearity, precision, accuracy, robustness, and limit of detection (LOD), the limit of quantification (LOQ) according to ICH guidelines. Results: The linear calibration curve was obtained in the concentration range of 0-50 μg/ml and gave an average correlation factor 0.992. The retention time was observed at 2.96 min. The Minimum concentration level at which the analyte can be reliably detected (LOD) and quantified (LOQ) were found to be 0.03 and 0.09 µg/ml, respectively. The relative standard deviation of intra and the inter-day assay was found to be less than 2. The dissolution studies show moderate dissolution (23.4%) after 45 min, but it reaches a plateau after approximately 25 min. Conclusion: This method was found to be simple, rapid and economic with less run time. The validated parameters manifest the method is reliable, linear, accurate and precise as well as robust with minor variations in chromatographic parameters. Therefore, the developed method can be applied for both routine analysis and quality control assay and it could be a very powerful tool to investigate the stability of escitalopram.

Determination of cucurbitacin E in some selected herbs of ayurvedic importance through RP-HPLC

Background: The consumption of the fruits of cucurbitaceae plants is widely popular among Indians dueto their various nutritional and medicinal purposes. Some of these plants are well reported in Ayurvedadue to their potential therapeutic importance. In particular, the plants of this family are wellcharacterized by the presence of its bitter principle, Cucurbitacin E which differs within the speciesdue to its genetic variations.Objectives: The objective of the study was to develop a validated RP-HPLC method for standardization insome widely consumed cucurbits with cucurbitacin E as a marker compound.Materials and methods: The RP-HPLC method was developed with a reverse phase C18 column, usingacetonitrile and water (1% glacial acetic acid) as mobile phase (70:30 v/v). The flow rate and lmax wereoptimized at 1 mL/min and 230 nm respectively. The HPLC method was validated in terms of accuracy,specificity, sensitivity, and repeatability as per ICH guideline.Results: The calibration curve was found linear in the concentration range of 1e100 mg/mL. The % RSD ofprecision and recovery was found to be <2%, which confirms high repeatability of the method. The results indicated that the content of cucurbitacin E was highest (0.0663% w/w) in Cucurbita pepo whereasLagenaria siceraria contains the lowest (0.0356% w/w).Conclusion: The study was able to explore the variation of cucurbitacin E content in some selected foodplants of Cucurbitaceae family. The applicability of the method can be established in nutraceutical industry for the effective quality control of cucurbits for safe human consumption.

RP-HPLC analysis of methanol extract of Viscum articulatum

Background: Viscum articulatum Burm. (Family: Loranthaceae) is commonly known as mistletoe. Inayurveda, the plant parts are used in “Kapha”, “Vata”, diseases of the blood, ulcer, and epilepsy. The plantparts are also used in urinary tract infection and wound infection. The plant contains five triterpenoidssuch as a-amyrin, lupeol, betulin, betulinic acid and oleanolic acid, exhibiting several pharmacologicalactivities including antimicrobial, anti-HIV, antitumor, antiviral activity.Objective: To ensure the content of uniformity of oleanolic acid, a RP-HPLC method has been developedfor estimation of oleanolic acid in V. articulatum aerial part.Material and methods: The RP-HPLC method was carried out in reverse phase C18 column, using methanol and water as mobile phase in the ratio of 95:5 (v/v), at the flow rate of 1 mL/min. The pH of aqueousphase was adjusted 3.2 with 1% (v/v) glacial acetic acid. The lmax was set at 210 nm.Results: The retention time of oleanolic acid was found at 21.5 ± 0.05 min. The linearity of the response wasfound to be 10e800 mg/mL. The coefficient of determinants of oleanolic acid was found to be (r2) 0.995 andequation Y ¼ 19462X þ 16,172. The LOD and LOQ were found to be for oleanolic acid (1.96% w/w) 0.197 ± 0.63and 0.623± 0.87 mg/mL, respectively. The developed method was accurate, specific, precise and reproducible.Conclusion: This RP-HPLC may be useful for quantitative estimation of the chemical constituents presentin the plant extract as well as the quality assessment of the herbal product.

Development And Validation Of Rp-Hplc Method For Simultaneous Estimation Of Gallic Acid, Curcumin And Piperine In An Ayurvedic Formulation

Objective: The objective of the present work was to establish a simple, precise, accurate and robust method for simultaneous estimation of gallic acid, curcumin and piperine from the marketed ayurvedic formulation by liquid chromatography. Methods: The separation was carried out on Hemochrom C18 Column (250 mm × 4.6 mm ID, 5 µm pore size) with a mobile phase methanol: acetonitrile: water (pH 3.2adjusted by using orthophosphate acid) in the ratio 70:20:10v/v by isocratic elution modeat 25 °C and the flow rate was setat0.8 ml/min. The analysis was carried out atisoabsorptive wavelength of 295 nm. Results: The retention time of gallic acid, curcumin and piperine was found to be 3.3(±0.2), 4.7 (±0.2) and 5.6 (±0.2) min, respectively. The linearity range for gallic acid, curcumin and piperine was found to be 10-70 μg/ml, 20-80 µg/ml and 2-14 µg/ml, respectively with the coefficient of linear regression greater than 0.99 for all markers. Mean percent recoveries for gallic acid, curcumin, and piperine were found within the limit of acceptance (99-100%). The percent relative standard deviation (%RSD) for precision and robustness was found less than 2%, which indicates the method is precise and robust. The developed method applied for quantification of these markers from the marketed ayurvedic formulation of Dekofcyn tablet. Conclusion: The developed method was found to be simple, rapid, precise and reproducible for standardization of Dekofcyn tablet and can be useful for other formulations containing these three markers.