Area Triangulation Method for Automatic Detection of Venous Emptying Maneuvers

Abstract Venous refilling time (VRT) can diagnose the presence of venous diseases in lower limbs. In order to calculate VRT it is necessary to determine the End of the Emptying Maneuvers (EEM). First Derivative Method (FDM) can be employed for automatic detection of the EEM, but its sensitivity to artifacts and noise can degrade its performance. In contrast, studies report that Area Triangulation Method (ATM) evinces effectiveness in biosignals point finding. This work compares the exactness of ATM and FDM for recognition of the EEM. The annotations made by 3 trained human observers on 37 photoplethysmography records were used as a reference. Bland-Altman graphics supported the analysis of agreement among human observers and methods, which was complemented with Analysis of variance and Multiple Comparisons statistical tests. Results showed that ATM is more accurate than FDM for automatic detection of the EEM, with statistically significant differences (p-value < 0.01).

Classification and Identification of Cynomorii Herba from Different Producing Areas Based on Fourier Rransform Infrared Spectroscopy and Chemometrics / 中国实验方剂学杂志

Objective: To realize the classification and identification of Cynomorii Herba from different producing areas based on fourier transform infrared spectroscopy (FTIR) and chemometrics. Method: FTIR spectrum data of 106 batches of Cynomorii Herba from 12 cities in 5 provinces were collected by transmission method and preprocessed. The FTIR fingerprints of Cynomorii Herba were established, and spectrum analysis was performed. The FTIR similarities of Cynomorii Herba from different producing areas were calculated by correlation coefficient method. The first derivative (1D) spectrum of average FTIR of Cynomorii Herba from different producing areas were obtained. The soft independent modeling of class analog (SIMCA) model based on principal component analysis (PCA) was established by the preprocessed 1D spectrum data. The orthogonal partial least squares (OPLS) model was established by top 6 principal components. Result: The FTIR fingerprint trend and main absorption peaks of Cynomorii Herba from different producing areas were basically the same,and 16 common characteristic absorption peaks were recognized. Similarity and 1D spectrum of FTIR fingerprint of Cynomorii Herba from different producing areas showed significant and unique characteristics. The established SIMCA model can realize the classification and identification of Cynomorii Herba from different provinces,while OPLS model can realize accurate classification and identification of Cynomorii Herba in different cities. The classification and identification of Cynomorii Herba from 12 city producing areas showed obvious geographical clustering characteristics. Conclusion: The established method based on FTIR and chemometrics can realize the classification and identification of Cynomorii Herba from 12 cities.

Evaluation of hypertension using first derivative features of photoplethysmography / 国际药学研究杂志

The photoplethysmography (PPG) signal is the standard technique to measure blood oxygen saturation and cardiac output, but the complete diagnostic value of PPG signals is not being used presently in clinical applications. Therefore, we are proposing a simple algorithm to extract blood flow parameters from the PPG signals and prove that blood vessels are altered, losing their elasticity in hypertensive people. Hypertension is a serious medical condition where the force of blood pumping through the arteries is strong as compared to the normal force. Hypertension is defined as blood pressure above 140/90mmHg and is considered to be severe if it exceeds 180/120mmHg. Blood pressure can be measured using various methods like auscultatory method and palpatory method. The manual method of blood pressure measurements based on a calibrated sphygmomanometer will be accurate only if performed precisely. A PPG sensor shows us the vascular condition of a person by allowing us to calculate blood flow parameters like systolic amplitude, pulse interval, augmentation index and stiffness index. Our study population includes 25 normal and 25 known hypertensive subjects. Parameters from PPG signal like systolic amplitude, pulse interval, and stiffness index was calculated directly. After taking first derivative of the signal features like i). Crest Time (CT), ii). Peak to peak time (ΔT) and iii). Stiffness index was also calculated. The parameters were statistically analyzed to prove that there is vascular wall health deterioration in prolonged hypertensive subjects.

Rapid Judgement of Blending Endpoint of Jingqi Shuangshen Capsules and Content Determination of Astragaloside Ⅳ by AOTF-NIR / 中国药房

OBJECTIVE:To establish the method for rapid judgement of blending endpoint of Jingqi shuangshen capsules and content determination of astragaloside Ⅳ. METHODS:AOTF-NIR combined with principal component analysis and Moving Block Standard Deviation method was used to identify the blending endpoint. First derivative combined with savitzky-golay filter method were used to spectrum pretreatment. The partial least square method was used to establish quantitative analysis model of the content of astragaloside Ⅳin mixed endpoint sample. The content of astragaloside Ⅳ in mixed endpoint sample was determined by HPLC-ELSD to validate the model. RESULTS:Methodology validation of content determination of astragaloside Ⅳ in mixed material sample and mixed endpoint sample was in line with the requirements. NIR monitoring results showed that the product reached the blending endpoint after 30 min. The results of NIR monitoring were generally consistent with the results of HPLC-ELSD. The principal component dimension of the quantitative model was 9;determination coefficients was 0.954 9;Root Mean Square of Calibration of the model was 0.039 2;Root Mean Square Error of Prediction of the model was 0.042 6. Predicted average value of astragaloside Ⅳ by NIR was 11.74 mg/g,and measured average value of astragaloside Ⅳ by HPLC-ELSD was 11.38 mg/g;average deviation was 3.16%. CONCLUSIONS:AOTF-NIR can rapidly judge the blending endpoint sample of Jingqi shuangshen capsules,rapidly determine the content of astragalosideⅣin mixed endpoint material,improve the quality control level of blending process and shorten blending cycle.

Determination of amlodipine and telmisartan in the compound tablet by first de-rivative UV spectrophotometry / 药学实践杂志

Objective To determine telmisartan and amlodipine assay in the compound tablet .Methods First derivative UV spectrophotometry was used at wavelength 236 nm for telmisartan and 390 nm for amlodipine .Results Telmisartan con-tent has a good linear relationship in the concentration range of (4~20) × 10-3 mg/ml .The standard curve equation is Y =0 .0043 X-0 .0005 and correlation coefficient R2 =0 .9993 .Amlodipine content has a good linear relationship in the concen-tration range of (10~90) × 10-3 mg/ml .The standard curve equation is Y =0 .0003 X+0 .0002 and correlation coefficient R2 =0 .9995 .Conclusion The assay results from this method are consistent with the results from HPLC .This procedure pro-vides a specific ,accurate and precise method to assay the amlodipine and telmisartan in compound tablet .

Analytical method development and validation for simultaneous estimation of Teneligliptin hydrobromide hydrate and Metformin hydrochloride from it’s pharmaceutical dosage form by three different UV spectrophotometric methods.

Three new UV spectrophotometric methods namely simultaneous equation, absorbance ratio and first derivative (zero crossing) spectroscopic methods were developed and validated for simultaneous estimation of teneligliptin hydrobromide hydrate and metformin hydrochloride in tablet formulation which were simple, sensitive, precise and accurate. In simultaneous equation method, absorbance was measured at 237 and 246 nm for both the drugs. Teneligliptin hydrobromide hydrate and metformin hydrochloride was estimated using 237 and 247.5 nm in absorbance ratio method. First derivative (zero crossing) method was based on the transformation of UV spectra in to first derivative spectra followed by measurement of first derivative signal at 237 and 246 nm for teneligliptin hydrobromide hydrate and metformin hydrochloride, respectively using 2 nm as wavelength interval (Δλ) and 1 as scaling factor. Developed methods were validated according to ICH guidelines including parameters viz., specificity, linearity and range, precision, accuracy, limit of detection and quantification. All the three methods showed linear response in the concentration range of 1-20 µg/ml for both the drugs. Results of method validation parameters follows ICH guideline acceptable limits. Based on the assay results obtained, methods were compared using one-way ANOVA followed by Bonferroni multiple comparison tests (95% confidence level) using computer based fitting program (Prism, Graphpad version 5, Graphpad Software Inc). Outcome of the statistical analysis proved that there was no considerable dissimilarity between all the developed methods. Methods were found to be simple, fast, highly sensitive, cost effective and hence can be useful for simultaneous estimation of teneligliptin hydrobromide hydrate and metformin hydrochloride in commercial tablet formulation for routine quality control analysis.

Simultaneous estimation of Aliskiren hemifumarate and Hydrochlorothiazide in combined Tablet Formulation by Simultaneous equation, Absorbance ratio and First derivative Spectroscopic Methods.

Three simple, sensitive, precise and accurate UV-spectroscopic methods namely simultaneous equation, absorbance ratio and first derivative (zero crossing) spectroscopic methods were developed and validated for simultaneous determination of aliskiren hemifumarate and hydrochlorothiazide in tablet dosage form. Simultaneous equation method was based on the measurement of absorbance at 271 and 280 nm for both the drugs. In absorbance ratio method 255 and 271 nm was used for the quantification of aliskiren hemifumarate and hydrochlorothiazide. First derivative method was involved in the conversion of UV-spectra in to first derivative spectra and measurement of first derivative signal at 241 and 280.2 nm for aliskiren hemifumarate and hydrochlorothiazide, respectively using 2 nm as wavelength interval (Δλ) and 1 as scaling factor. Methods were validated as per ICH guidelines including parameters viz., specificity, linearity and range, precision, accuracy, limit of detection and quantification. All the methods were found to be linear in the concentration range of 6-300 μg/ml for aliskiren hemifumarate and 0.5-25 μg/ml for hydrochlorothiazide. Results of validation studies follows ICH guideline acceptable limits. Methods were compared based on the assay results obtained using one-way ANOVA followed by Bonferroni multiple comparison tests (95% confidence level) as appropriate using computer based fitting program (Prism, Graphpad version 5, Graphpad Software Inc). Results of statistical analysis revealed that there was no significant difference between simultaneous equation, absorbance ratio and first derivative method. Developed methods were simple, rapid, highly sensitive and cost effective as compared to existing methods and can be useful for simultaneous estimation of aliskiren hemifumarate and hydrochlorothiazide in commercial tablet formulation for routine quality control.

Differential Spectrophotometric Method for Determination of Cefquinome Sulphate.

Differential first derivative (ΔD1) method is developed for the quantitative analysis of cefquinome sulphate (CS) in bulk and dosage form. The method is based on measuring the ΔD1 of CS in alkaline solutions against its neutral aqueous solutions as blanks. The proposed method is sensitive and highly specific, since the interference of the excipients or impurities is nullified. Beer’s law was obeyed over the concentration range 4-20 μg/mL with a limit of detection and limit of quantification 1.5 μg/mL and 4.8 μg/mL respectively.

Spectrophotometric methods for determination of tapentadol hydrochloride.

Two simple, fast, environmental friendly and reliable spectrophotometric methods were developed for determination of tapentadol hydrochloride in bulk and synthetic mixture containing the possible excipients. The first method is based on measuring the first derivative values of aqueous solution of the drug at 228 nm (method I) and the second method based on measuring the second derivative values at 235 nm (method II). Calibration graphs constructed at their wavelengths of determination were linear in the concentration range of tapentadol 5- 60 μg.ml-1 for both methods. The proposed methods have been extensively validated as per ICH guidelines. The developed spectrophotometric methods in this study are simple, accurate, precise, specific and reproducible and can be directly applied to pharmaceutical dosage form.

Extraction and purification technology for different extracts from Lamiophlomis rotata in industrialization / 中草药

Objective: The macroporous adsorptive resin chromatographic column combining with polyamide chromatographic column was used to separate the flavonoides, phenylethanoidglycosides, iridoid glycosides, and high polarity ingredients (such as alkaloid salts and sugars) in industrialization. Methods: Water extract from Lamiophlomis rotata (WELR) was separated and enriched by series and parallel method of polyamide and macroporous adsorptive resins and CCPP serial laminar analysis, and was ultrafiltrated by LM-125 ultrafiltration apparatus, then was dried under the reduced pressure by JYT-50 LN multipurpose kinesis back flow extract concentration subassembly. WELR, 70% ethanol solution eluate I (70% ethanol solution eluted polyamide column), 70% ethanol solution eluate II (70% ethanol solution eluting macroporous resin column), and ultrafiltration matter. The total flavonoids and total phenylethanoid glycosides were determined by aluminum nitrate-sodium nitrite UV spectrophotometry. The total iridoid glycosides were determined by the first derivative spectrophotometry. Shanzhiside methylester and 8-O-acetyl shanzhiside methylester were determined and the changes of total iridoid glycosides ingredients were investigated in the different elution requirement by HPLC. Results: Ethanol (70%) was used as dissolvent. Using the "introduction from superior surface" sample introduction mode and "introduction from superior surface" eluting mode in polyamide chromatographic column, the "introduction from inferior surface" sample introduction mode and "introduction from superior surface" eluting mode in the macroporous adsorptive resin chromatographic column, yields of 70% ethanol solution eluate I, 70% ethanol solution eluate II, and ultrafiltration matter were 2.43%, 20.80%, and 82.60%, respectively. Conclusion: This production technology may transform the experimental achievement to industrial production successfully.

A Validated Comparitative LC and Ratio First Derivative Spectrophotometric Method for the Simultaneous Determination of Levocetrizine dihydrochloride and Montelukast sodium in Bulk and Pharmaceutical dosage forms.

A new simple, rapid, precise reverse phase-high performance liquid chromatographic (RP-HPLC) and ratio spectra first derivative spectroscopy (1DD) methods has been developed for the simultaneous determination of Levocetrizine dihydrochloride (Levo) and Montelukast sodium (Mont) in bulk active pharmaceutical ingredient (API) as well as in tablet dosage form. In RP-HPLC method, separation was performed using phenomex-luna 5μ C8 (2) (100Å, 250 X 4.6 mm) column by using acetonitrile: 0.5% triethylamine in water (90:10 v/v) pH adjusted to 5.5 ± 0.1 with orthophosphoric acid. The flow rate was 0.8 ml/min with UV detection monitored at 231 nm. The retention time was 3.8 and 5.2 min for Levo and Mont respectively. In ratio spectra first derivative method, linearity range was found to be 2-32 μg/mL and 3-30 μg/mL for Levo and Mont respectively. From the first derivative (1DD) suitable wavelength was selected and amplitudes were measured at 240 nm and 281 nm for the assay of Levo and Mont by considering concentration of 18 μg/mL of Mont and 24 μg/mL of Levo as a suitable divisor, respectively. The validation of method was carried out according to ICH guidelines.

Comparative study of analytical methods by direct and first-derivative UV spectrophotometry for evaluation of losartan potassium in capsules / Estudo comparativo de métodos analíticos por espectrometria de UV directa e derivada de primeira ordem para a avaliação de losartano potássico em cápsulas

Losartan potassium is an antihypertensive non-peptide agent, which exerts its action by specific blockade of angiotensin II receptors. The aim of the present study was the validation and application of analytical methods for the quality control of losartan potassium 50 mg in pharmaceutical capsules, using direct and first-derivative UV spectrophotometry. Based on losartan potassium spectrophotometric characteristics, a signal at 205 nm of the zero-order spectrum and a signal at 234 nm of the first-derivative spectrum, were found adequate for quantification. The results were used to compare these instrumental techniques. The linearity between the signals and concentrations of losartan potassium in the ranges of 3.0-7.0 mg L-1 and 6.0-14.0 mg L-1 for direct and first-derivative spectrophotometry in aqueous solutions, respectively, presented a correlation coefficient (r) of 0.9999 in both cases. The methods were applied for losartan potassium in capsule dosage obtained from local pharmacies, and were shown to be efficient, easy to apply and low cost. These methods do not use polluting reagents and require relatively inexpensive equipment.

O losartano potássico é um agente anti-hipertensivo não peptídico, que exerce sua ação por bloqueio específico dos receptores da angiotensina II. Este trabalho propôs a validação e aplicação de métodos analíticos orientados ao controle de qualidade de losartano potássico 50 mg na forma farmacêutica cápsula, utilizando a espectrofotometria direta e derivada de primeira ordem na região do UV. Baseado nas características espectrofotométricas de losartano potássico, um sinal a 205 nm do espectro de ordem zero e um sinal a 234 nm do espectro de primeira derivada foram adequados para a quantificação. Os resultados foram usados para comparar essas duas técnicas instrumentais. O coeficiente de correlação entre as respostas e as concentrações de losartano potássico na faixa de 3,0-7,0 mg L-1 e 6,0-14,0 mg L-1 para espectrofotometria direta e derivada de primeira ordem em solução aquosa, respectivamente, foi de (r) of 0,9999 para ambos os casos. Os métodos foram aplicados para quantificação de losartano potássico em cápsulas obtidas de farmácias de manipulação locais e demonstraram ser eficientes, fáceis de aplicar e de baixo custo. Além disso, não necesitam de reagentes poluentes e requerem equipamentos economicamente viáveis.

Análise derivativa de dados hiperespectrais medidos em nível de campo e orbital para caracterizar a composição de águas opticamente complexas na Amazônia / Derivative analysis of hyperespectral data measured at field and orbital level to characterize the composition of optically complex waters in the amazon

A técnica de análise derivativa de dados espectrais foi usada para estudar a variação dos constituintes opticamente ativos (COAs) na água, por meio de dados de campo e de imagens do sensor orbital Hyperion/EO-1. A imagem Hyperion usada neste estudo foi adquirida no dia 23 de junho de 2005, no final do período de cheia. Uma campanha de campo foi realizada entre 23 e 29 de junho de 2005, para coletar dados espectrais e limnológicos in situ. A imagem foi pré-processada visando eliminar faixas de pixels anômalos e convertida de valores de radiância para reflectância de superfície, portanto, corrigidos dos efeitos de absorção e espalhamento atmosféricos. Uma análise da correlação foi realizada para examinar a associação da reflectância e de sua primeira derivada espectral com as concentrações dos COAs. Melhores resultados foram obtidos após a diferenciação dos espectros, o que ajudou a reduzir a influência de efeitos indesejáveis, provindos de diferentes fontes de radiância, sobre as medidas de reflectância da superfície da água realizadas em ambos os níveis de aquisição de dados. Por meio de ajustes de regressões empíricas, considerando o conjunto de dados Hyperion, a primeira derivada espectral em 711 nm explicou 86 por cento da variação da concentração de sedimentos inorgânicos em suspensão (µg.l-1) e a primeira derivada espectral em 691 nm explicou 73 por cento da variação na concentração da clorofila-alfa (µg.l-1). As relações de regressão foram não-lineares, pois, em geral, as águas que se misturam na planície de inundação Amazônica se tornam opticamente complexas. A técnica de análise derivativa hiperespectral demonstrou potenciais para mapear a composição dessas águas.

Derivative analysis of spectral data was used as a technique to study the variation of optically active constituents (OACs) of water, using field data and hyperspectral imagery of EO-1 Hyperion orbital sensor. The Hyperion image used in this study was acquired on June 23, 2005, at the end of the high water period for the Amazon River. A field campaign was carried out between June 23 and 29, 2005 to collect spectral and limnological in situ data. The image was pre-processed to remove stripes of abnormal pixels and converted from radiance to surface reflectance values, thus, correcting the effects of atmospheric absorption and scattering. A correlation analysis was carried out to examine the association of the spectral reflectance and its first derivative to the concentrations of OACs. Better results were obtained after spectra differentiation, which helped to reduce the influence of undesirable effects, coming from different sources of radiance, on the measurements of water surface reflectance taken at both data acquisition levels. Through empirical regression fits, considering the Hyperion dataset, the first spectral derivative at 711 nm explained 86 percent of the variation of suspended inorganic sediment concentration (µg.l-1), and the first derivative at 691 nm explained 73 percent of the variation of chlorophyll-a concentration (µg.l-1). The regression relations were nonlinear because, generally, the water masses that mix in the Amazon floodplain become optically complex. The hyperspectral derivative analysis demonstrated potential for mapping the composition of these waters.

Determination of the Content of Vitamin E in Muyan Capsule by First-Derivative Spectrophotometry / 中国药房

OBJECTIVE:To determine vitamin E in muyan capsule.METHODS:The content of vitamin E in muyan capsule was determined by first-derivative spectrophotometry with detection wavelength at 230nm.RESULTS:The linear range of vitamin E was 14.98 ～ 24.96? g? mL-1(r=0.999 8).The average recovery of vitamin E was 100.1%(RSD=0.26%).CONCLUSION:The method is simple,rapid and accurate,and applicable for the determination of vitamin in muyan capsule.

Study on Dissolution Test Methods for Diclofenac Sodium Suppository / 中国药房

OBJECTIVE:To establish a good method for determining the dissolution rates of diclofenac sodium suppository METHODS:The dissolution method Ⅰ and Ⅱ of ChP(2000) were compared,the first derivative spectrophotometry was used and the parameters(T50,Td,m) obtained from these samples were brought for correlation analysis RESULTS:The dissolution rate of diclofenac sodium suppository from the dissolution method Ⅰ and Ⅱ were remarkably different,and the dissolution method Ⅱ was better than Ⅰ CONCLUSION:The method established by this study is suitable for the quality control of diclofenac sodium suppository,and the percentage of dissolution of diclofenac sodium suppository in 45min more than 80% is the standard of quality control