[Source Apportionment of Morphine in Wastewater]

It is a new approach to identify legal or illegal use of morphine through information on municipal wastewater. However, the sources of morphine in wastewater are complex, and distinguishing the contribution of different sources has become a key issue. A total of 262 influent samples from 61 representative wastewater treatment plants in a typical city were collected from October 2022 to March 2023. The concentrations of morphine, codeine, thebaine, papaverine, noscapine, and monoacetylmorphine were analyzed in wastewater and poppy straws. Combined with the proportion of alkaloids in poppy straws, the source analysis of alkaloids in wastewater was analyzed using the ratio method and positive matrix factorization model (PMF). Only five alkaloids were detected in wastewater, and monoacetylmorphine, a metabolite of heroin, was not detected. The concentrations of morphine and codeine were significantly higher than those of noscapine, papaverine, and thebaine. By constructing the ratios of codeine/(morphine + codeine) and noscapine/(noscapine + codeine), the source of poppy straw could be qualitatively distinguished. The PMF results showed that three sources of morphine for medical use, poppy straw, and codeine contributed 44.9%, 43.7%, and 9.4%, respectively. The different sources varied in these months due to the COVID-19 and influenza A outbreaks, in which the use of drugs containing poppy straws and codeine was the main source, whereas the use of morphine analgesics remained relatively stable. Inventory analysis further demonstrated the reliability of the source contributions from the PMF model, and morphine was not abused in this city.

Aerodynamic Thermal Breakup Droplet Ionization in Mass Spectrometric Drug Analysis

Aerodynamic thermal breakup droplet ionization (ATBDI) in mass spectrometric drug analysis is considered. Cocaine, heroin, and the main alkaloids of opium (morphine, codeine, papaverine) were chosen as the test compounds. The principles of ATBDI ionization are discussed. The dependences of the intensities of the peaks of the target compounds on temperature during ATBDI ionization are also considered. In some cases, a comparison of ATBDI ionization with electrospray ionization (ESI) was performed. In addition, a comparison of methods is demonstrated by the analysis of confiscated opium that was provided by the local police department. Five major alkaloids are found in opium: morphine, codeine, thebaine, papaverine, and narcotine.

Evaluation of the efficiency of continuous wavelet transform as processing and preprocessing algorithm for resolution of overlapped signals in univariate and multivariate regression analyses; an application to ternary and quaternary mixtures

Wavelets have been adapted for a vast number of signal-processing applications due to the amount of information that can be extracted from a signal. In this work, a comparative study on the efficiency of continuous wavelet transform (CWT) as a signal processing tool in univariate regression and a pre-processing tool in multivariate analysis using partial least square (CWT-PLS) was conducted. These were applied to complex spectral signals of ternary and quaternary mixtures. CWT-PLS method succeeded in the simultaneous determination of a quaternary mixture of drotaverine (DRO), caffeine (CAF), paracetamol (PAR) and p-aminophenol (PAP, the major impurity of paracetamol). While, the univariate CWT failed to simultaneously determine the quaternary mixture components and was able to determine only PAR and PAP, the ternary mixtures of DRO, CAF, and PAR and CAF, PAR, and PAP. During the calculations of CWT, different wavelet families were tested. The univariate CWT method was validated according to the ICH guidelines. While for the development of the CWT-PLS model a calibration set was prepared by means of an orthogonal experimental design and their absorption spectra were recorded and processed by CWT. The CWT-PLS model was constructed by regression between the wavelet coefficients and concentration matrices and validation was performed by both cross validation and external validation sets. Both methods were successfully applied for determination of the studied drugs in pharmaceutical formulations.

[Simultaneous determination of 5 kinds of alkaloids in Kechuanning tablets by SPE-UPLC under different UV-vis wavelength]

The paper is to establish a method for simultaneous determination of 5 kinds of alkaloids in ephedra and poppy which are in Kechuanning tablets. Solid-phase extraction (SPE) was adopted in pretreatment, and a UPLC method with 2 different wavelengths had been developed: 210 nm for the detection of morphine, codeine phosphate, ephedrine hydrochloride and pseudoephedrine hydrochloride, and 251 nm for papaverine hydrochloride. The column used was Acquity UPLC BEH C18 (100 mm x 2.1 mm ID, 1.7 microm) with linear gradient elution using acetonitrile and 0.1% phosphoric acid. The flow rate was 0.4 mL.min-1, and the column temperature was 30 degrees C. The linear response range was 0.375 0 - 12.50 microg.mL-1 for morphine, 0.064 32 - 2.144 microg.mL-1 for codeine phosphate, 0.030 06 - 1.002 microg.mL-1 for papaverine hydrochloride, 1.126 - 37.52 microg.mL-1 for ephedrine hydrochloride, 0.287 8 - 9.592 microg.mL-1 for pseudoephedrine hydrochloride (r = 0.999 7). The average recoveries of these compounds were 99.26%, 100.6%, 95.29%, 100.1% and 97.48%, respectively. This is a more reasonable and credible method of quality control for Kechuanning tablets.

DETERMINATION OF NARCOTINE AND PAPAVERINE BY INFRA-RED SPECTROPHOTOMETRY AND NON-AQUEOUS TITRATION

An infra-red spectrophotometric method for the determination of narcotine in the presence of papaverine in carbon tetrachloride or chloroform solution is described. The carbonyl group of the lactone ring present in narcotine displays strong absorption at 1760 cm. −1 and the intensity of the band observed at this wavelength provides an index of the concentration of the narcotic. By conventional nonaqueous titration the amount of both alkaloids may be estimated quantitatively and the papaverine content of a mixture obtained readily by difference.

THE QUANTITATIVE SEPARATION OF PAPAVERINE FROM NARCOTINE IN MIXTURES

A method for the quantitative separation of papaverine from narcotine in mixtures by using ammonium reinckate is described, and also its application to the determination of these alkaloids in opium. The identity and purity of these alkaloids isolated from opium is shown by means of ultra-violet, visible and infra-red spectrophotometry. The complete extraction of these alkaloids from the triturate of opium by chloroform was demonstrated by paper chromatography. The regeneration of pure papaverine from the reineckate complex is also described.

Validation and application of chemometrics-assisted spectrophotometry and liquid chromatography for simultaneous determination of two ternary mixtures containing drotaverine hydrochloride

Three methods were developed for the determination of two ternary mixtures containing drotaverine hydrochloride (DR) with caffeine and paracetamol (mixture 1) and DR with metronidazole and diloxanide furoate (mixture 2). The first method depends on HPLC separation on an RP C18 column at ambient temperature with the mobile phase methanol-water, pH 3.1 (50 + 50, v/v) and UV detection at 213 nm for mixture 1, and the mobile phase acetonitrile-25 mM potassium dihydrogen phosphate, pH 4.6 (55 + 45, v/v) with UV detection at 235 nm for mixture 2. The other two chemometric methods applied were partial least squares (PLS-1) and principal component regression (PCR). These approaches were successfully applied to quantify the five drugs in two ternary mixtures using information included in the UV absorption spectra of appropriate solutions in the wavelength range of 210-300 nm with 1 nm intervals. Calibration of PCR and PLS-1 models was evaluated by internal validation (prediction of compounds in its own designed training set of calibration), by cross-validation (obtaining statistical parameters that show the efficiency for a calibration fit model), and by external validation (using laboratory-prepared mixtures and pharmaceutical preparations). The proposed methods were successfully applied for the determination of the two ternary combinations in laboratory-prepared mixtures and commercial tablets; the results of PLS-1 and PCR methods were compared with the HPLC method, and a good agreement was found.

Determination of diclofenac sodium and papaverine hydrochloride in tablets by HPLC method

A HPLC method for simultaneous determination of diclofenac sodium and papaverine hydrochloride in tablets was developed and validated. The determination was performed with a Zorbax SB-C18 column, mobile phase: methanol-water (60:40, v/v), flow rate: 1 mL min(-1) and UV detection at 278 nm.

[Absorption of papaverine, laudanosine and cepharanthine across human intestine by using human Caco-2 cells monolayers model]

Absorption of papaverine (PAP), laudanosine (LAU) and cepharanthine (CEP) as some chemical constituents of traditional Chinese medicines in human intestine were studied. By using Caco-2 (the human colonic adenocarcinoma cell lines) cell monolayers as an intestinal epithelial cell model, the permeability of PAP, LAU and CEP were studied from apical side (AP side) to basolateral side (BL side) or from BL side to AP side. The three alkaloids were measured by reversed-phase high-performance liquid chromatography coupled with UV detector. Transport parameters and apparent permeability coefficients (Papp) were then calculated and compared with those of propranolol as a control substance of high permeability and atenolol as a control substance of poor permeability. The Papp values of PAP, LAU and CEP were (3.524+/-0.223) x 10(-5), (2.821+/-0.050) x 10(-5) and (6.524+/-0.052) x 10(-5) cm s(-1) from AP side to BL side, and (5.095+/-0.508) x 10(-5), (2.646+/-0.146) x 10(-5) and (5.495+/-0.036) x 10(-5) cm s(-1) from BL side to AP side, respectively. Their Papp values were identical with those of propranolol, which is a transcellular transport marker. On the other hand, the efflux transport of PAP was 1.45 times higher than its influx transport with 0.69 rate of P(app A-->B)/P(app B-->A). But P(app A-->B)/P(app B-->A) values of LAU and CEP were 1.07 and 1.19, respectively, which suggested that the efflux transport have not been involved in their absorbed mechanism in Caco-2 cells monolayers. There is a good correlation between the Papp value and apparent distribution coefficient (Log D) at pH 7.35 for the three alkaloids. PAP, LAU and CEP can be absorbed across intestinal epithelial cells, and they are completely absorbed compounds. PAP may have been involved in efflux mechanism in Caco-2 cells monolayers model from the basolateral-to-apical direction. The O/W (oil/water) partition coefficient plays key role in their transmembrane permeation.

Simultaneous determination of nifuroxazide and drotaverine hydrochloride in pharmaceutical preparations by bivariate and multivariate spectral analysis

The quantitative predictive abilities of the new and simple bivariate spectrophotometric method are compared with the results obtained by the use of multivariate calibration methods [the classical least squares (CLS), principle component regression (PCR) and partial least squares (PLS)], using the information contained in the absorption spectra of the appropriate solutions. Mixtures of the two drugs Nifuroxazide (NIF) and Drotaverine hydrochloride (DRO) were resolved by application of the bivariate method. The different chemometric approaches were applied also with previous optimization of the calibration matrix, as they are useful in simultaneous inclusion of many spectral wavelengths. The results found by application of the bivariate, CLS, PCR and PLS methods for the simultaneous determinations of mixtures of both components containing 2-12microgml(-1) of NIF and 2-8microgml(-1) of DRO are reported. Both approaches were satisfactorily applied to the simultaneous determination of NIF and DRO in pure form and in pharmaceutical formulation. The results were in accordance with those given by the EVA Pharma reference spectrophotometric method.

Papaverine PVC membrane ion-selective electrodes based on its ion-exchangers with tetraphenylborate and tetrathiocyanate anions

The construction and general performance of novel potentiometric membrane ion selective electrodes for determination of papaverine hydrochloride has been described. They are based on the formation of the ion association complexes of papaverine (PA) with tetraphenylborate (TPB)(I) or tetrathiocyanate (TTC)(II) counter anions as electro-active material dispersed in a PVC matrix. The electrodes show fast, stable, near Nernstian response for 1 x 10(-2) to 6 x 10(-5) M and 1 x 10(-2) to 1 x 10(-5) M for PA-TPB and PA-TTC respectively at 25 degrees C over the pH range of 3-5.0 with a cationic slope of approximately 56.5 +/- 0.5 mV/decade for both sensors respectively. The lower detection limit is 4 x 10(-5) and 8 x 10(-6) M for PA- I and PA-II respectively with fast response time ranging from 20-45 sec. Selectivity coefficients for PA relative to a number of interfering substances were investigated. There is a negligible interference from the studied cations, anions, and pharmaceutical excipients. The determination of 4.0- 3000.0 microg/ml of PA in aqueous solutions shows an average recovery of 99.1% and a mean relative standard deviation of 1.4 at 100microg/ml. The direct determination of PA in some formulations (Vasorin injection) gave results that compare favorably with those obtained using the British Pharmacopoeia method. Potentiometric titration of PA with sodium tetraphenylborate and potassium thiocyanate as titrants utilizing the papaverine electrode as an end point indicator electrode has been carried out.

Spectrophotometric determination of pipazethate HCl, dextromethorphan HBr and drotaverine HCl in their pharmaceutical preparations

A simple, accurate and highly sensitive spectrophotometric method is proposed for the rapid determination of pipazethate hydrochloride, dextromethorphan hydrobromide and drotaverine hydrochloride using chromotrope 2B (C2B) and chromotrope 2R (C2R). The method consists of extracting the formed ion-associates into chloroform in the case of pipazethate HCl and dextromethorphan HBr or into methylene chloride in the case of drotaverine HCl. The ion-associates exhibit absorption maxima at 528, 540 and 532 nm with C2B and at 526, 517 and 522 nm with C2R for pipazethate HCl, dextromethorphan HBr and drotaverine HCl, respectively. The calibration curves resulting from the measurements of absorbance-concentration relations (at the optimum reaction conditions) of the extracted ion-pairs are linear over the concentration range 4.36-52.32 microg mL(-1) for pipazethate, 3.7-48.15 microg mL(-1) for dextromethorphan and 4.34-60.76 microg mL(-1) for drotaverine, respectively. The effect of acidity, reagent concentration, time, solvent and stoichiometric ratio of the ion-associates were estimated. The molar absorptivity and Sandell sensitivity of the reaction products were calculated. Statistical treatment of the results reflects that the procedure is precise, accurate and easily applied for the determination of the drugs under investigation in pure form and in their pharmaceutical preparations.

Extraction and determination of papaverin in pericarpium papaveris using aqueous two-phase system of poly(ethylene glycol)–(NH4)2SO4 coupled with high-performance liquid chromatography

Based on aqueous two-phase system (ATPS) of poly(ethylene glycol) (PEG)-(NH4)2SO4, a simple pretreatment approach was developed for the extraction and determination of papaverin in pericarpium papaveris. The influence factors on phase behavior of the ATPS and partition behavior of papaverin was investigated, and partition mechanism based on the hydrophobic interaction between PEG and analyte molecules was proposed. Under the optimal conditions, the extraction efficiencies for papaverin were 93-96%, and the recoveries of the added standard were 97-106% with relative standard deviations of 1.8-2.5%. Combined with a high-performance liquid chromatography (HPLC) method, this extraction technique has been successfully applied to the determination of papaverin in pericarpium papaveris with the detection limit of 2 ng mL(-1) and the linear range of 0.10-10 microg mL(-1). Compared with the conventional liquid-liquid extraction or solid-phase extraction, this method was more environmentally benign, more cost effective and much simpler due to the direct injection of the upper phase into HPLC system.

Spectrophotometric and spectrodensitometric determination of paracetamol and drotaverine HCl in combination

Thin-layer chromatography, first derivative, ratio spectra derivative spectrophotometry and Vierordt's method have been developed for the simultaneous determination of paracetamol and drotaverine HCl. TLC densitometric method depends on the difference in Rf values using ethyl acetate:methanol:ammonia (100:1:5 v/v/v) as a mobile phase. The spots of the two drugs were scanned at 249 and 308 nm over concentration ranges of 60-1200 microg/ml and 20-400 microg/ml with mean percentage recovery 100.11%+/-1.91 and 100.15%+/-1.87, respectively. The first derivative spectrophotometric method deals with the measurements at zero-crossing points 259 and 325 nm with mean percentage recovery 99.25%+/-1.08 and 99.45%+/-1.14, respectively. The ratio spectra first derivative technique was used at 246 and 305 nm with mean percentage recovery 99.75%+/-1.93 and 99.08%+/-1.22, respectively. Beer's law for first derivative and ratio spectra derivative methods was obeyed in the concentration range 0.8-12.8 and 0.4-6.4 microg/ml of paracetamol and drotaverine HCl, respectively. Vierordt's method was applied to over come the overlapping of paracetamol and drotaverine HCl in zero-order spectra in concentration range 2-26 and 2-40 microg/ml respectively. The suggested methods were successfully applied for the analysis of the two drugs in laboratory prepared mixtures and their pharmaceutical formulation. The validity of the methods was assessed by applying the standard addition technique. The obtained results were statistically agreed with those obtained by the reported method.

Application of derivative, derivative ratio, and multivariate spectral analysis and thin-layer chomatography-densitometry for determination of a ternary mixture containing drotaverine hydrochloride, caffeine, and paracetamol

New selective, precise, and accurate methods are described for the determination of a ternary mixture containing drotaverine hydrochloride (I), caffeine (II), and paracetamol (III). The first method uses the first (D1) and third (D3) derivative spectrophotometry at 331 and 315 nm for the determination of (I) and (III), respectively, without interference from (II). The second method depends on the simultaneous use of the first derivative of the ratio spectra (DD1) with measurement at 312.4 nm for determination of (I) using the spectrum of 40 microg/mL (III) as a divisor or measurement at 286.4 and 304 nm after using the spectrum of 4 microg/mL (I) as a divisor for the determination of (II) and (III), respectively. In the third method, the predictive abilities of the classical least-squares, principal component regression, and partial least-squares were examined for the simultaneous determination of the ternary mixture. The last method depends on thin-layer chromatography-densitometry after separation of the mixture on silica gel plates using ethyl acetate-chloroform-methanol (16 + 3 + 1, v/v/v) as the mobile phase. The spots were scanned at 281, 272, and 248 nm for the determination of (I), (II), and (III), respectively. Regression analysis showed good correlation in the selected ranges with excellent percentage recoveries. The chemical variables affecting the analytical performance of the methodology were studied and optimized. The methods showed no significant interferences from excipients. Intraday and interday assay precision and accuracy values were within regulatory limits. The suggested procedures were checked using laboratory-prepared mixtures and were successfully applied for the analysis of their pharmaceutical preparations. The validity of the proposed methods was further assessed by applying a standard addition technique. The results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by the manufacturer's method.

[Determination of papaverine in Qiangli Pipalu by HPLC]

OBJECTIVE

To establish a method for the determination of the papaverine content in Qiangli Pibalu by HPLC.

METHOD

A C18 column with a solvent system of acetonitrile-0.02 mol x L(-1) sodium dihydrogen phosphate (0.2% triethylamine, phosphoric acid, at pH 3) (25:75) and UV detection 240 nm were used. The flow rate was 1.0 mL x min(-1). The column temperature was maintained at 40 degrees C.

RESULT

There was a good linear relationship between the absorption value and the concentration in the range of 0.020 2-0.100 5 microg for papaverine. The average recovery rates were 99.1% (RSD 2.3%).

CONCLUSION

The method is simple, accurate and can be used to determine the contents in Qiangli Pibalu.

Application of new membrane selective electrodes for the determination of drotaverine hydrochloride in tablets and plasma

The construction and electrochemical response characteristics of poly vinyl chloride (PVC) membrane sensors for the determination of drotaverine hydrochloride were described. The sensors are based on the use of the ion association complexes of drotaverine cation with sodium phosphotungestate (Dro-PTA) or ammonium reineckate (Dro-R) counter anions as ion exchange sites in the PVC matrix. The performance characteristics of these sensors, which were evaluated according to IUPAC recommendations, reveal a fast, stable and linear response for drotaverine over the concentration range 10(-5) to 10(-2) M with cationic slopes of 49.55 and 51.36 mV per concentration decade. The direct potentiometric determination of drotaverine hydrochloride using the proposed sensors gave average recoveries of 99.95+/-0.71 and 100.04+/-0.60 for Dro-PTA and Dro-R, respectively. The sensors are used for determination of drotaverine hydrochloride in tablets, in its mixture with caffeine and paracetamol and in plasma. Validation of the method shows suitability of the proposed sensors for use in the quality control assessment of drotaverine hydrochloride. The developed method was found to be simple, accurate and precise when compared with a reported HPLC method.

Determination of nifuroxazide and drotaverine hydrochloride in pharmaceutical preparations by three independent analytical methods

Three new, different, simple, sensitive, and accurate methods were developed for quantitative determination of nifuroxazide (I) and drotaverine hydrochloride (II) in a binary mixture. The first method was spectrophotometry, which allowed determination of I in the presence of II using a zero-order spectrum with an analytically useful maximum at 364.5 nm that obeyed Beer's law over a concentration range of 2-10 microg/mL with mean percentage recovery of 100.08 +/- 0.61. Determination of II in presence of I was obtained by second derivative spectrophotometry at 243.6 nm, which obeyed Beer's law over a concentration range of 2-10 microg/mL with mean recovery of 99.82 +/- 1.46%. The second method was spectrodensitometry, with which both drugs were separated on a silica gel plate using chloroform-acetone-methanol-glacial acetic acid (6 + 3 + 0.9 + 0.1) as the mobile phase and ultraviolet (UV) detection at 365 nm over a concentration range of 0.2-1 microg/band for both drugs, with mean recoveries of 99.99 +/- 0.15 and 100.00 +/- 0.34% for I and II, respectively. The third method was reversed-phase liquid chromatography using acetonitrile-water (40 + 60, v/v; adjusted to pH 2.55 with orthophosphoric acid) as the mobile phase and pentoxifylline as the internal standard at a flow rate of 1 mU/min with UV detection at 285 nm at ambient temperature over a concentration range of 2-10 microg/mL for both drugs, with mean recoveries of 100.24 +/- 1.51 and 100.08 +/- 0.78% for I and II, respectively. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulations containing the above drugs with no interference from other dosage form additives. The validity of the suggested procedures was further assessed by applying the standard addition technique which was found to be satisfactory, and the percentage recoveries obtained were in accordance with those given by the EVA Pharma reference spectrophotometric method.

[Determination of papaverine in seeds of Papaver somniferum L. and soup of chafing dish by high performance liquid chromatography-fluorescence detection]

A method of reversed-phase high performance liquid chromatography coupled with fluorescence detection was developed for the separation and determination of papaverine in seeds of Papaver somniferum L. and soup of chafing dish. The liquid chromatographic experiment was carried out under the following conditions: the detector was a fluorescence with excitation wavelength at 285 nm and emission wavelength at 355 nm. An RP-C18 column (250 mm x 4.6 mm i.d., 5 microm) was used. The mobile phase was a mixture of methanol and 0.02 mol/L ammonium acetate (70: 30, v/v). The flow rate was 0.8 mL/min. A linear range was obtained from 0.1 ng to 0.1 microg with a good correlation. The lowest detection limit was 0.02 ng. The average recovery of seeds for Papaver somniferum L. was 99.0% - 100.8%. The method is rapid, accurate, sensitive and suitable for the separation and determination of papaverine in foods.

Thin-layer chromatography-densitometry and liquid chromatography analysis of alkaloids in leaves of Papaver somniferum under stress conditions

The effect of stress conditions on the concentrations of secondary metabolites were examined during various developmental stages of Papaver somniferum plants. P. somniferum plants were grown in laboratory conditions (Budakalász). The experiment consisted of 22 treatments. Significantly different alkaloid contents can be observed under different stress conditions. In general, the alkaloid contents of plants are very low; therefore, a highly sensitive and reliable method has to be developed for analysis. The amount of alkaloids was measured by 2 separation and detection techniques. Accuracy of the thin-layer chromatography method for quantitative analysis is limited. Without purification of samples the background is too noisy. Column liquid chromatography is a sensitive and relatively inexpensive method that allows precise quantitative determination of the alkaloid content.

[Analysis of two year heroin seizures in the Liege area]

The results of heroin analysis from seizures in the Liege area during the last two years are presented in this article. Between January 2003 and January 2005, 50 samples were analysed in the Laboratory of Clinical Toxicology and Forensic Toxicology of the University of Liege. Mean heroin concentration was 14,7%. Noscapine and papaverine, other opium alcaloïds, were simultaneously present with heroin. As diluents, we only identified caffein and acetaminophen.

HPLC and chemometric assisted spectrophotometric methods for simultaneous determination of diprophylline, phenobarbitone and papaverine hydrochloride

Three methods are developed for the simultaneous determination of diprophylline (DP), phenobarbitone (PH) and papaverine hydrochloride (PP). The chromatographic method depends on a high performance liquid chromatographic (HPLC) separation on a reversed-phase C18 column with a mobile phase consisting of 0.02 M potassium dihydrogen phosphate, pH 3.5--acetonitrile (55:45 v/v). Quantitation was achieved with UV detection at 210 nm based on peak area. The other two chemometric methods applied were principal component regression (PCR) and partial least squares (PLS-1). These approaches were successfully applied to quantify the three drugs in the mixture using the information included in the UV absorption spectra of appropriate solutions in the range 215-245 nm with the intervals Delta lambda = 0.2 nm. The calibration PCR and PLS-1 models were evaluated by internal validation (prediction of compounds in its own designed training set of calibration), by cross-validation (obtaining statistical parameters that show the efficiency for a calibration fit model) and by external validation over laboratory-prepared mixtures and pharmaceutical preparations. The PCR and PLS-1 methods require neither any separation step, nor any priori graphical treatment of the overlapping spectra of the three drugs in a mixture. The results of PCR and PLS-1 methods were compared with HPLC method obtained in pharmaceutical formulation and a good agreement was found.

Transport properties and electroanalytical response characteristics of drotaverine ion-selective sensors

The construction and electroanalytical response characteristics of poly(vinyl chloride) matrix ion-selective sensors (ISSs) for drotaverine hydrochloride are described. The membranes incorporate ion-association complexes of drotaverine with tetraphenylborate, picrate, tetraiodomercurate, tetraiodobismuthate, Reinecke salt, and heteropolycompounds of Keggin structure-molybdophosphoric acid, tungstophosphoric acid, molybdosiliconic acid and tungstosiliconic acid as electroactive materials for ionometric sensor controls. These ISSs have a linear response to drotaverine hydrochloride over the range 8 x 10(-6) to 5 x 10(-2) mol L(-1) with cationic slopes from 51 to 58 mV per concentration decade. These ISSs have a fast response time (up to 1 min), a low determination limit (down to 4.3 x 10(-6) mol L(-1)), good stability (3-5 weeks), and reasonable selectivity. Permeabilities and ion fluxes through a membrane were calculated for major and interfering ions. Dependences of the transport properties of the membranes on the concentrations of the ion exchanger and near-membrane solution and their electrochemical characteristics are presented. The ISSs were used for direct potentiometry and potentiometric titration (sodium tetraphenylborate) of drotaverine hydrochloride. Results with mean accuracy of 99.1+/-1.0% of nominal were obtained which corresponded well to data obtained by use of high-performance liquid chromatography.

Determination of two ternary mixtures containing phenobarbitone by second derivative of the ratio spectrum-zero-crossing and HPLC methods

A spectrophotometric method is developed for the determination of ternary mixtures with overlapping spectra. The method is based on the use of the second derivative of the ratio spectrum with a zero-crossing technique. The ratio spectrum was obtained by dividing the absorption spectrum of the mixture by that of one of the components. The concentration of the other components are then determined from their respective calibration graphs treated similarly. The method is accurate, non-destructive and do not require resolutions of equations. The method has been applied for the resolution of two ternary mixtures, namely, phenobarbitone, methylphenobarbitone and phenytoin (1), and phenobarbitone, papaverine HCl and piperazine acefyllinate (2). Also, a HPLC method was developed for determination of phenobarbitone, papaverine and HCL and piperazine acefyllinate. The HPLC method depends upon using ODS column with a mobile phase consisting of acetonitrile-5 mM aqueous heptane sulfonic acid sodium salt (50:50, v/v) and adjusted to apparent pH 4 using acetic acid. Quantitation was achieved with UV detection at 220 nm based on peak area. The proposed methods were applied for the determination of the two ternary combinations in synthetic mixtures and in commercial pharmaceutical products. The results obtained were precise and accurate.

[Influence of fertilizers on yield and yield components of opium from Papaver somniferum Linn]

The effect of fertilizer on the yield and yield components of opium from Papaver somniferum L.cv.Ikkanshu were investigated from 1993 to 1995. The weight of opium per one capsule was tendency to increase in the order of peat moss > pulverized charcoal > compound fertilizer, but the differences among the results were not significant. Furthermore, no difference in the capsule weight per 100 m2 and the yields of opium and alkaloids per 100 m2 were detected. The significant difference was only observed when the data were compared among the weights and yields of different years. The difference among the yield of opium was mainly due to the weight of opium per one capsule. The weight of opium per one capsule showed a high correlation with capsule husk weight. The alkaloids contents in opium obtained with a different fertilizer application showed no difference. Morphine content at the first lancing was about 11%, and the value decreased with the order of lancing. On the contrary, the codeine and the thebaine content did not change during lancing and the value were 6-7% and 3%, respectively. The papaverine and the noscapine content decreased in the order of lancing.

Flow injection determination of papaverine based on its sensitizing effect on the chemiluminescence reaction of permanganate-sulfite

A novel chemiluminescence (CL) method for the determination of papaverine (PAP) has been developed by combining the flow injection technique and its sensitizing effect on the weak CL reaction between sulfite and acidic permanganate. A mechanism for the CL reaction has been proposed on the basis of fluorescent and chemiluminescence spectra. The CL response is proportional to the concentration of PAP over the range 0.2-10 micro mol L(-1). The detection limit of PAP is 0.10 micro mol L(-1) (3 s) with a relative standard deviation (RSD) of 2.0% for 10 repetitive determinations of 1.0 micro mol L(-1) PAP. Interferences from other alkaloids in the opium, such as morphine and codeine, are negligible except that of narcotine. The method has been satisfactorily used for the determination of PAP in injections and compound liquorice tablets.

Photooxidation of papaverine, papaverinol and papaveraldine in their chloroform solutions

Papaverine hydrochloride, papaverinol, and papaveraldine chloroform solutions were exposed to UV light of 254 nm in atmospheric, aerobic and anaerobic (helium) conditions. The same degradation products appear (TLC) in the above papaverine hydrochloride chloroform solutions. However, the rate of papaverine hydrochloride degradation processes is enhanced as a function of oxygen pressure. Papaverinol and papaveraldine photooxidation products are essentially not different from those observed in the above papaverine hydrochloride solutions. However, the amount of an unknown brown degradation product (X) is the greatest in the papaverinol chloroform solution degraded. That brown compound was previously observed in papaverine either hydrochloride or sulfate injection solutions on their storage even when protected from daylight. The preliminary X product structure development was undertaken (TLC, molecular weight, elemental analysis, UV/VIS, IR and 13C MAS NMR spectroscopy).

[Determination of papaverine hydrochloride in skin and blood and the drug contents in pig skin]

OBJECTIVE

To explore the application of ultraviolet spectrophotometer in determining papaverine hydrochloride content in blood and skin and to determine the intradermal content after local external application of papaverine hydrochloride.

METHODS

Phosphate buffer solution (pH = 10, ionic strength = 0.4) was added into the blood or ground skin tissue containing papaverine hydrochloride, and papaverine hydrochloride was extracted with chloroform-hexane mixture (ratio:2:3). After oscillation and centrifugation, partial organic phase was retrieved and dried in 60 degrees C water bath. The dried product was dissolved in 1 mol/L HCl and then underwent filtration through 0.2 micron membrane. The ultraviolet apectrophotometry was applied to determine the content of papaverine hydrochloride in the filtrate. 2% papaverine hydrochloride cream was applied on pig's skin and skin specimen was retrieved at given time to determine the papaverine hydrochloride content in skin tissue with ultraviolet spectrophotometry.

RESULTS

The absorbance spectrum of the extract was typical of that of papaverine hydrochloride, with no miscellaneous peak. The extractive rate of papaverine hydrochloride in blood of was more than 92% and that in skin tissue more than 87%. Eight hours after external application of 2% papaverine hydrochloride cream on pig skin, the content of papaverine hydrochloride in skin tissue was more than 90 micrograms/g, significantly higher than the effective concentration of papaverine hydrochloride.

CONCLUSIONS

Ultraviolet spectrophotometry is a simple, economical and reliable method for the determination of papaverine hydrochloride content in blood and skin tissue, with good reproducibility and sensibility. External application of papaverine hydrocholine cream can provide efficient permeation and drug concentration in the skin.

Spectrophotometric determination of meclozine HCl and papaverine HCl in their pharmaceutical formulations

A simple, accurate and highly sensitive spectrophotometric method is proposed for the rapid determination of meclozine and papaverine hydrochlorides using chromotrope 2B (C2B) and chromotrope 2R (C2R). The method consists of extracting the formed ion-associates into chloroform in the case of meclozine HCl and into methylene chloride in case of papaverine HCl. The ion-associates exhibit absorption maxima at 536 and 524 nm for C2B and C2R with meclozine HCl and at 540 and 528 nm with papaverine HCl, respectively. Meclozine can be determined up to 4.0 and 2.6 mg ml(-1), using C2B and C2R, respectively, while papaverine can be determined up to 1.68 and 1.37 mg ml(-1), respectively. The effect of acidity, reagent concentration, time, solvent and stoichiometric ratio of the ion-associates were studied. The molar absorptivity and Sandell sensitivity of the reaction products were calculated. The method was applied to the determination of the drugs in their pure state or pharmaceutical preparations with mean recovery values of 99.63-100.80 and 99.75-100.08% and coefficient of variation 0.945-2.210 and 1.020-1.268 for meclozine HCl and papaverine HCl, respectively.

[Preparation and evaluation of alkyl ether-bonded phase for reversed-phase high performance liquid chromatography]

A new silane coupling agent, beta-(3,4-epoxycyclohexyl)ethyltrimethoxy silane, was for the firsty time used to react with octanol, then the intermediate product was coupled onto porous silica to obtain a novel bonded phase for reversed-phase high performance liquid chromatography (RP-HPLC). Characterization of prepared packing was carried out with elemental analysis, solid-state 13C nuclear magnetic resonance spectrometry (NMR), Fourier transform infrared(FT-IR) spectroscopy. Chromatographic evaluations were carried out by using a mixture of organic compounds and methanol-water as the binary mobile phase. The results showed that the stationary phase has excellent chromatographic properties and resist to hydrolysis at a pH value between 2.5 and 7.5. The silanophilic activity of the OEBP was weakened because of the existence of the cyclohexyl group in the packing. It can be efficiently used for the separation of basic compounds.

Retention of ionizable compounds on HPLC. 8. Influence of mobile-phase pH change on the chromatographic retention of acids and bases during gradient elution

The relationships between retention and mobile-phase pH in gradient elution are studied for acids and bases. The apparent pH shift caused by the increasing amount of acetonitrile and methanol has been determined starting from a wide range of pH values. It is shown that good relationships between the retention of ionizable compounds and the pH of the aqueous buffer can be established if the same type of buffer (ammonium acetate in this work) is used for all pH points. Equations are proposed to fit the gradient retention data to the pH of the aqueous buffer. The proposed equation gives an account of the relative variation of the pKa of the compound in the reference to the variation of the pH of the buffer as both parameters change during gradient elution.

[Determination of Pericarpium papaveris in foods accompanied with some fragrant substances by high performance liquid chromatography]

An HPLC method for the determination of Pericarpium papaveris in foods accompanied with some fragrant substances is described. The Pericarpium papaveris in food was extracted in alkaline condition with CHCl3-C2H5OH(9:1, V/V) and analyzed by reversed-phase HPLC by using a YWG C6H5 column and acetonitrile-methanol-water as mobile phase. The calibration curves of papaverine, morphine and codeine were linear in the range of 1.2 mg/L-100 mg/L and the mean recoveries were from 79.3% to 86.1%. The method has a good specificity and accuracy.

Analytical method for the determination of strychnine in tissues by gas chromatography/mass spectrometry: two case reports

This paper describes an analytical method for strychnine determination in biological samples by gas chromatography/mass spectrometry and their application in the investigation of two cases involving strychnine ingestion: A fatal case and a clinical one. The strychnine is isolated from biological samples using a liquid-liquid extraction procedure. The clean-up procedure is performed using an acid solution. Papaverine is used as internal standard in the quantification of strychnine. In the analysed specimens, the limits of quantification were 0.1 microg/ml or 0.1 microg/g. The recovery rate ranged from 75.0% to 98.7% and the coefficients of variation ranged from 4.8% to 10.5%.

[Determination of alkaloids in pericarpium papaveris by gas chromatography with wide bore capillary column]

A method for the simultaneous determination of codeine, morphine, thebaine, papaverine and narcotine in pericarpium papaveris by gas chromatography with wide bore capillary column is described. The major components in pericarpium papaveris were extracted with methanol and chloroform by supersonic extraction and evaporation. The residue was dissolved in methanol. The resulting solution was used for analysis. The conditions for determination were: FID detector, HP-1 capillary column, 5 m x 0.53 mm x 2.65 microns film, column temperature 260 degrees C, The method requires 10 minutes for the whole analysis. The average recoveries of codeine, morphine, thebaine, papaverine and narcotine in the sample were 94.0%, 96.5%, 93.8%, 91.0% and 91.4% respectively. The relative standard deviations were from 0.92% to 2.75%. The advantages of this method are simple, rapid, accurate and sensitive.

Simultaneous assay of ephedrine hydrochloride, theophylline, papaverine hydrochloride and hydroxyzine hydrochloride in tablets using RP-LC

The analytical problem was to control the quality of imported antiasthmatic tablets containing ephedrine hydrochloride, theophylline, papaverine hydrochloride and hydroxyzine hydrochloride. The aim of the analytical method for the assay was to separate, identify and quantify all compounds, at the same time. A gradient capable RP-LC system was used, using a commercially packed Nucleosil C18 column connected to a dual channel variable, programmable wavelength detector. The analysis was performed in the gradient program of increasing concentration of acetonitrile in water. The influence of pH of the mobile phase was established. The proposed method is reliable, reproducible, easy to perform and satisfies the aim.

[Determination of pericarpium papaveris(yingsuqiao) in bottom material of chafing dish by high performance liquid chromatography(HPLC)]

Morphine, codeine and papaverine in bottom material of chafing dish were determined by HPLC. The conditions were as follows: C18 column, mobile phase V(CH3OH):V(25 mmol/L KH2PO4) = 90:10, the flow rate 1 mL/min and the wavelength 254 nm. These three compounds were entirely separated. The blank and positive comtrasts were being done simultaneously. The detection limit was 0.1 mg/L. The experiment showed that this method is sensiuve, accurate and reliable.

Development of a predictive model for batch membership of street samples of heroin

Street samples (n = 31) of heroin were analysed by gas chromatography with flame ionisation detection to determine opiate, noscapine and papaverine content. Using this data, the chromatograms obtained could be resolved into eight groups by visual examination of the data. The concentrations of opiates were significantly correlated (P < 0.05) with the exception of the pairs 6-O-monoacetylmorphine/noscapine and morphine/6-O-monoacetylmorphine. This precludes the use of simple cluster analysis for determining and predicting the relationship of different street samples. Application of Fisher's linear discriminant analysis to the data set indicated that 91.9% of the samples could be discriminated including pairs which could not be discriminated by eye. A blind trial (n = 2) resulted in the correct assignment to street sample. Application of such methods may provide, in the future, a powerful tool for the prediction of batch membership of drugs at the street level.

Gas chromatographic/mass spectrometric detection of narcotine, papaverine, and thebaine in seeds of Papaver somniferum

In addition to codeine and morphine, three more compounds: narcotine (noscapine), papaverine, and thebaine were found in Indian and Netherlands poppy seeds (Papaver somniferum L). The compounds were detected by a GC/MS technique and the identities were confirmed by comparing retention times and ion ratios with the known references. The concentrations of codeine, morphine, thebaine, papaverine, and narcotine were 44, 167, 41, 67, and 230 micrograms/g in Indian poppy seeds, and were 1.8, 39, 1.0, 0.17, 0.84 micrograms/g in Netherlands poppy seeds, respectively. Because these compounds may be urinary products after poppy seed consumption, the lowest detectable concentrations of codeine, morphine, thebaine, papaverine, and narcotine in urine are of interest and were found to be 4, 4, 5, 0.4, and 4 ng/ml, respectively. The detection of urinary narcotine, papaverine, or thebaine may be utilized to differentiate poppy seed consumption from illicit codeine, morphine, or heroin use.

Proton relaxation and spin label studies of papaverine localization in ionic micelles

The localization of papaverine (PAV) in micelles of zwitter-ionic N-hexadecyl-N, N-dimethyl-3-ammonio-1-propanesulfonate (HPS), cationic cetyltrimethylammonium chloride (CTAC), and anionic sodium dodecyl sulfate (SDS) in D2O was studied by 1H NMR and ESR in the presence and absence of 5-doxyl- or 12-doxyl-stearic acid. PAV, surfactants, and spin probes are characterized by restricted anisotropic motion in micelles. The rotational correlation time of doxyl fragment was in the range of 0.2 to 0.5 nanoseconds. Binding of PAV to micelles decreases the mobility of both probes, suggesting the localization of PAV inside the hydrophobic part of micelles near the micelle-water interface. According to the NOE data, the methoxy groups of PAV are located in the vicinity of the nitrogen atom in CTAC and HPS micelles, the methoxy groups of the PAV heterocycle being immersed slightly deeper inside the micelle. The T1 relaxation enhancements by two different spin probes show that the H5 and methoxy substituents of the PAV heterocycle are in close proximity to the alpha-CH2 of acyl chains in all types of micelles, whereas H3 and H12 are the most distant from the alpha-CH2. No significant differences were found for the protonated and neutral PAV in SDS micelles at pD 4.9 and 11.2. These data show that the geometry of the PAV-micelle complex is practically independent of the PAV charge and surfactant head-group.

Impurities, adulterants and diluents of illicit heroin. Changes during a 12-year period

Changes in the content of impurities, adulterants and diluents are described for 383 samples of illicit heroin seized in the western part of Denmark during the 12-year period 1981 through 1992. A wide range in purity was found within each year, whereas the average purity did not vary much from one year to another. The average purity of wholesale samples (45%) was only slightly higher than the purity of retail samples (36%). The SW Asian type of heroin, containing high concentrations of noscapine, predominated from the mid-eighties. Heroin base and heroin hydrochloride each accounted for approximately half of the samples during the eighties. However, in recent years the base form has become predominant. During the early eighties caffeine and procaine were the most frequent additives next to sugars. During the middle and late eighties an increasing number of heroin samples were cut with phenobarbital and methaqualone. During the early nineties the occurrence of phenobarbital and methaqualone has decreased, whereas paracetamol in combination with caffeine has become predominant. Re-analyses of samples which had been kept in storage for several years showed that most samples had not changed after being stored in the dark for a couple of years at room temperature. However, storage for more than 5 years often resulted in decomposition, particularly in samples consisting of the SW Asian type of heroin.

Determination of papaverine and cocaine by use of a precipitation system coupled on-line to an atomic absorption spectrometer

A continuous-precipitation flame-atomization atomic absorption spectrometric method for the determination of papaverine and cocaine hydrochlorides is proposed. The method is based on the precipitation of reineckates by injection of Reinecke's salt into a carrier containing the alkaloids and their subsequent retention on a stainless steel filter. In this way, papaverine and cocaine hydrochlorides can be determine over the ranges 5-85 and 50-850 micrograms ml-1 with a relative standard deviation of 1.3 and 3.2%, respectively, and a sampling frequency of 150 h-1. The proposed method is more sensitive and selective for papaverine than it is for cocaine and can be applied to the determination of papaverine HCl in pharmaceutical preparations.

High-performance liquid chromatographic method for the determination of drotaverine in human plasma and urine

A simple and sensitive HPLC method for the determination of drotaverine in human plasma and urine has been developed. Alkalinized plasma or urine was extracted with organic solvent and the basic components in the organic phase were back-extracted into 0.1 M HCl. An aliquot of the aqueous layer was injected onto the column and the eluent was monitored at 254 nm. Separation was performed on a C18-column with 0.02 M sodium dihydrogen phosphate-methanol (30:70, v/v) containing perchlorate ion at pH 3.2 as mobile phase. Drotaverine was well resolved from the plasma constituents and internal standard. An excellent linearity was observed between peak-height ratios and plasma concentrations and the intra- and inter-assay coefficients of variation were always < 10%. The lowest limit of detection (signal-to-noise ratio 3:1) was 6 ng/ml. The method is suitable for therapeutic monitoring and pharmacokinetic studies of drotaverine in humans as well as in animal models.

Ion-pair reversed-phase liquid chromatographic identification and quantitation of papaverine congeners

A reversed-phase ion-pair high-performance liquid chromatographic separation was developed for identification and quantitation of papaverine drug congeners, namely papaverine (1), moxaverine (2), drotaverine (3), and ethaverine (4) hydrochlorides. A synthetic reference mixture of the four congeners in the range 1-4 micrograms showed good separation. With a reference standard (codeine phosphate), the relative retention times to codeine were 1.356, 1.984, 2.46, and 2.91 (mean of six) for 1, 2, 3, and 4, respectively. Good linearity was obtained in the quantitation of 1 and 2 in the range 1-2 micrograms [correlation coefficient (r), 0.9978 and 0.9997, respectively] and 3 and 4 in the range 2-4 micrograms, (r, 0.9998 and 0.9991, respectively). Analysis of some commercial dosage forms containing one of these congeners showed good recovery with sufficient accuracy and precision. The method was sensitive and permitted the use of small sample sizes or unit doses.

Simultaneous sequential determination of compounds of toxicological interest in mixtures by derivative spectroscopy

An absorption spectroscopic method was developed for the sequential determination of mixture components. The proposed method is straightforward and convenient and provides optimal results that increase the potential of spectrophotometric techniques as applied to date. The method was applied to the sequential resolution of mixtures of pure components of toxicological interest yielding close UV absorption bands by using derivative spectroscopy.

Determination of ethaverine and papaverine using ion-selective electrodes

Ion-selective poly(vinyl chloride) membrane electrodes for the opium alkaloids papaverine and ethaverine are presented. The electrode membranes contain ion pairs of the alkaloids with the anionic counter ion tetraphenylborate. The detection limits for all electrodes were approximately 2 x 10(-6) mol dm-3 at pH 5.0 in 100 mmol dm-3 buffered solutions and the measured slopes were close to the values theoretically expected. The selectivity coefficient observed for the ethaverine-tetraphenylborate electrode is 10(-1.1) with respect to papaverine. The suitability of the membranes for single-use electrodes is discussed.

Stability of papaverine hydrochloride and phentolamine mesylate in injectable mixtures

The stability of papaverine hydrochloride and phentolamine mesylate combined in a single vial was studied. Injectable mixtures (10 mL) of papaverine hydrochloride 300 mg and phentolamine mesylate 5 mg (from two sources) were prepared by adding the contents of one vial of lyophilized phentolamine mesylate to the contents of one vial of papaverine hydrochloride injection. The vials were stored at 5 degrees C and 25 degrees C. Duplicate aliquots of the mixtures were obtained, and the concentrations of papaverine hydrochloride and phentolamine mesylate remaining at time 0 and after 1, 2, 5, 10, 20, and 30 days were determined in triplicate by a stability-indicating high-performance liquid chromatographic assay. The concentration of papaverine hydrochloride stored in the vials remained constant (less than 1% loss) over the 30-day period at both 5 degrees C and 25 degrees C. Phentolamine mesylate was less stable than papaverine but still retained more than 97% of its original concentration after 30 days at 5 degrees C and more than 95% of its original concentration at 25 degrees C. Papaverine hydrochloride and phentolamine mesylate are stable in injectable mixtures when stored for up to 30 days at 5 degrees C or 25 degrees C.