Determination of Cannabinoids in Cannabis sativa Oil and Infused Ice Cream by LC-DAD Method.

BACKGROUND: Cannabis sativa is known to produce a class of terpenophenolic compounds named cannabinoids. The two main ones are cannabidiol (CBD) and tetrahydrocannabinol (THC), which have therapeutic properties. In the development of cannabis-based preparations, it is important to have suitable analytical methods for the analysis of the principal cannabinoids. OBJECTIVE: This study aimed to develop and validate a simple and rapid HPLC method with photodiode array detection for determination of CBD and THC in Cannabis sativa oil extract and infused ice cream, including a stability study. METHOD: Chromatographic separation of CBD and THC was performed with a C18 column, with a mobile phase consisting of acetonitrile and water with formic acid (80 + 20 v/v) in isocratic elution mode, with detection at 208 nm for CBD and 280 nm for THC and 1.0 mL/min flow rate. RESULTS: The method was linear over a range of 1-5 µg/mL for CBD, and 20-100 µg/mL for THC; the relative standard deviation was <3.6%, the recovery ranged between 98.8 and 102.5% for oil and between 84 and 94% for ice cream, QL was 0.33 µg/mL for CBD and 2.30 µg/mL for THC, and the assay demonstrated adequate selectivity. CBD and THC were stable for at least 28 days under light protection at 22°C, 4°C, and -20°C in the oil and for at least 60 days at -20°C in the ice cream. CONCLUSIONS: The results showed that the method was suitable for quantitative determination of CBD and THC in Cannabis sativa oil extract and infused ice cream, and it is useful for quality control purposes. HIGHLIGHTS: The method is simple and fast, and it is useful for the quality control of a new product corresponding to an ice cream based on a Cannabis sativa oil extract.

Determination of the Chemical Stability of Dapagliflozin by LC/DAD and MS/MS Methods.

A simple and fast stability-indicating liquid chromatographic method with diode array detection (DAD) was developed and validated for the determination of dapagliflozin (DAPA) in bulk and tablets, in the presence of its major degradation products (DP). The drug was subjected to hydrolytic, oxidative, photolytic, thermal and humidity/thermal stress conditions, showing significant degradation under humidity/thermal with the formation of two DP, which were preliminarily identified by liquid chromatography with diode array detector coupled with electrospray ionization-tandem mass spectrometry (HPLC-DAD-ESI-MS/MS). Chromatographic separation of dapagliflozin and its DP was achieved with a core-shell RP-18 column, using acetonitrile and water as mobile phase in isocratic elution mode. The described method was linear over a range of 50-150 µg/mL. For precision, the relative standard deviation (RSD) was <1.3%, the recovery was 99.64-100.11%, and the assay demonstrated adequate selectivity. The degradation kinetics of dapagliflozin was evaluated corresponding to first-order under thermal and humidity/thermal stress conditions. Dapagliflozin was well resolved from its drug products showing the power of stability-indicating of the method. The results showed that the proposed method was found to be suitable for routine analysis, quantitative determination and the stability study of dapagliflozin in pharmaceutical samples.

Modified Ravitch Procedure and Autologous Cartilage Graft for Pectus Arcuatum.

Pectus arcuatum presents with sternal angle protrusion and bilateral cartilage deformity. A modified Ravitch procedure is the most common surgical approach. A graft to fill up the osteotomy may be necessary to ensure a stable correction. Studies of the behavior of a cartilage graft transplanted to a human bone defect are scarce. We present a case of autologous rib cartilage graft for sternotomy stabilization during pectus arcuatum repair. Graft viability and new bone formation were proved by computed tomography. Autologous cartilage rib graft is a biocompatible substitute available in the same surgical field with satisfactory results and minimal morbidity.

Carbamazepine Biosensor Development for Epilepsy Patient Screening.

The San Carlos population in Chile is an example of an underserved community due to lack of timely access to regular controls and laboratory results. One particular challenge is the adherence to treatment of Epilepsy patients. In this work, we present the design and proof-of-concept of a Point of Care Device (POCD) to measure carbamazepine levels in saliva to screen for correct dose prescription among epilepsy patients. We present the Screen Printed Electrode design and activating circuit and preliminary results to verify feasibility of the biosensor. Future steps include the fabrication of the device itself and validation with the target population.

Degradation studies of quetiapine fumarate by liquid chromatography-diode array detection and tandem mass spectrometry methods.

Quetiapine fumarate (QUE) is an antipsychotic agent with a chemical structure that is susceptible to degradation; therefore, it is important to study its stability using appropriate analytical tools. Knowledge of the stability profile of a drug is important because chemical degradation of its active component often results in a loss of potency, affecting its efficacy and safety. This current work reports degradation studies of QUE as drug substance, under different stress conditions such as oxidation, hydrolysis, heat, humidity and photolysis, by a stability-indicating LC method. The chemical stability was evaluated using a simple HPLC/diode array detection method, with a core-shell C18 column under isocratic conditions, which allows the separation of all primary degradation products (DPs) in a short run time. QUE was mainly degraded under oxidative and hydrolytic conditions, with the formation of three and two DPs, respectively, which were identified by electrospray ionization-tandem mass spectrometry. The method was properly validated in terms of linearity, accuracy, precision, selectivity, robustness and quantitation limit. Commercial tablets containing 25 mg of QUE were quantified, with results obtained within the United States Pharmacopeia limits. The proposed method is suitable to assess the stability and perform routine analysis of QUE in pharmaceutical samples.

Determination of vortioxetine and its degradation product in bulk and tablets, by LC-DAD and MS/MS methods.

Vortioxetine hydrobromide (VOR), is a novel antidepressant used for the treatment of major depressive disorder. It has a chemical structure susceptible to degradation, therefore it is important to have suitable analytical methods to determine VOR in presence of its main degradation products (DP), because if the compound degrades, this could result in diminution of the therapeutic activity and safety. A simple HPLC method with photodiode array detection was developed and validated for determination of VOR in bulk and tablets, in the presence of its major DP. The drug was subjected to oxidative, hydrolytic, and photolytic stress conditions, showing significant degradation under oxidation with the formation of one DP, which was identified by ESI-MS/MS. A C18 column was used, with mobile phase consisting of acetonitrile and water with acetic acid and triethylamine in isocratic elution mode, with detection at 228 nm and 1.0 mL/min flow rate. The assay was linear in the 25-125 µg/mL concentration range. For precision, the RSD was <1.8%, the recovery was 100.0-101.6%, and the method demonstrated adequate selectivity. The method was successfully applied to quantify VOR in tablets. The results showed that the method is useful for routine analysis and for quality control purposes.

Stability-Indicating Liquid Chromatographic Methods with Photodiode Array Detection and Light Scattering Detection for Simultaneous Determination of Candesartan and Hydrochlorothiazide.

Development, validation and comparison of two stability-indicating LC methods, one with photodiode array detector (DAD) and the other with evaporative light scattering detector (ELSD), were performed for simultaneous determination of candesartan cilexetil (CANC) and hydrochlorothiazide (HCTZ), in pharmaceutical samples. A RP-18 column (125 mm × 4 mm, 5 µm) was used for separation of CANC, HCTZ and its major degradation products, using acetonitrile and phosphate buffer (pH 6.0) for DAD method and acetonitrile and water with acetic acid and triethylamine (pH 4.1) for ELSD method, as mobile phase in a gradient mode. The response with ELSD was fitted to a power function and the DAD response by a linear model over a range of 32-160 µg/mL for CANC and 25-125 µg/mL for HCTZ. The precision and accuracy of the methods were similar, with RSD below 3.0% and recovery between 98.1% and 103.9%. The drugs were subjected to stress conditions of hydrolysis, oxidation, photolysis, humidity and temperature. The degradation products were satisfactory separated from the main peaks and from each other. Both drugs mainly degrade by hydrolysis, showing the formation of one degradation product for HCTZ and two for CANC; its identification was conducted by LC/MS/MS. The methods were successfully applied to the analysis of CANC and HCTZ in combined commercial tablets. The performance of DAD and ELSD methods are comparable, therefore both methods are suitable for stability study and determination of CANC and HCTZ in pharmaceutical samples.

[Pediculicide effect of a Eucaliptus globulus L formulation]. / Efecto pediculicida de una formulación en base a Eucaliptus globulus L.

INTRODUCTION: Pediculosis capitis is a public health problem with a high prevalence. The emergence of parasite resistance to conventional pediculicide is of great concern worldwide. OBJECTIVE: To develop alternatives pediculicide, effective and safe, based on the essential oil of Eucaliptus globulus. METHOD: Through bioassays active concentrations ranges of the essential oil were established, and proceeded to develop a standardized, stable, pharmaceutical form, evaluating its effects on our population. RESULTS: The results showed 100% effectiveness; short time of death, ovicidal action, activity on the adhesion of the egg, and low toxicity. DISCUSSION: In addition to great effect, the inability of the parasite to become resistant to the chemical composition of the essential oil makes this formulation an alternative to the problem of head lice solution.

Efecto pediculicida de una formulación en base a Eucaliptus globulus L / Pediculicide effect of a Eucaliptus globulus L formulation

Introduction: Pediculosis capitis is a public health problem with a high prevalence. The emergence of parasite resistance to conventional pediculicide is of great concern worldwide. Objective: To develop alternatives pediculicide, effective and safe, based on the essential oil of Eucaliptus globulus. Method: Through bioassays active concentrations ranges of the essential oil were established, and proceeded to develop a standardized, stable, pharmaceutical form, evaluating its effects on our population. Results: The results showed 100% effectiveness; short time of death, ovicidal action, activity on the adhesion of the egg, and low toxicity. Discussion: In addition to great effect, the inability of the parasite to become resistant to the chemical composition of the essential oil makes this formulation an alternative to the problem of head lice solution.

Introducción: La pediculosis capitis es un problema de salud pública con una alta prevalencia. La aparición de resistencia del parásito a los pediculicidas convencionales es de gran preocupación a nivel mundial. Objetivo: Desarrollar alternativas pediculicidas, efectivas y seguras, en base al aceite esencial de Eucaliptus globulus. Método: A través de bioensayos se establecieron rangos de concentraciones activas del aceite esencial, y se procedió al desarrollo de una forma farmacéutica, estandarizada, estable, evaluando sus efectos en nuestra población. Resultados: Los resultados mostraron 100% de efectividad; corto tiempo de muerte, acción ovicida, actividad sobre la adherencia del huevo, y baja toxicidad. Discusión: Además de la gran efectividad, la imposibilidad del parásito de adquirir resistencia a la composición química del aceite esencial hace de esta formulación una solución alternativa al problema de la pediculosis.

Comparison of Stability-Indicating LC Methods Using Light Scattering and Photodiode Array Detection with Monolithic Column for Determination of Quinapril and Hydrochlorothiazide.

Rapid stability-indicating LC methods for simultaneous analysis of quinapril and hydrochlorothiazide were developed, validated and compared using evaporative light scattering detection (ELSD) and diode array detection (DAD). For the separation of quinapril, hydrochlorothiazide and its major degradation products, a monolithic column was used and the analytes were eluted within 7 min, applying gradient mobile phase in both methods. Quinapril was subjected to hydrolytic, oxidative, thermal, humidity and photolytic stress conditions. Degradation products were well resolved from main peaks and from each other, proving the stability-indicating power of the methods. The response with DAD was linear and the response with ELSD was fitted to a power function, for quinapril and hydrochlorothiazide concentrations of 20-160 and 12.5-100 µg mL(-1), respectively. DAD method achieved better precision than ELSD method, the LOQ of DAD was lower and the accuracy of the methods was similar. Quinapril degrade by hydrolysis and thermal stress, showing the formation of quinaprilat and quinapril diketopiperazine as degradants, which were identified by MS-MS. The methods were successfully applied to quantify quinapril and hydrochlorothiazide in commercial tablets. LC-DAD and LC-ELSD methods are suitable to assess the stability and routine analysis of quinapril and hydrochlorothiazide in pharmaceutical industry.

Stability-indicating LC method for the simultaneous determination of lisinopril and hydrochlorothiazide.

A simple and rapid stability-indicating liquid chromatographic method was developed and validated for the simultaneous determination of lisinopril and hydrochlorotiazide (HCTZ) in drug substances and dosage forms in the presence of degradation products. Forced degradation studies were conducted on the pure drugs under hydrolytic, oxidative, thermal and photolytic conditions. A chromatographic separation of the two drugs and its degradation products was achieved with an RP-18 column, using methanol, acetonitrile and phosphate buffer (pH 7.1; 0.05 M) (15:15:70, v/v/v) as mobile phase at a flow rate of 0.8 mL min(-1) and UV detection at 210 nm. Lisinopril and HCTZ were well resolved from its degradation products showing the stability-indicating capability of the method. The described method was linear over a range of 40-200 µg mL(-1) for lisinopril and 25-175 µg mL(-1) for HCTZ. The assay was also selective, accurate and precise for lisinopril and HCTZ determination. This method represents an alternative to the United States Pharmacopeia (USP) method showing shorter retention time. The method was successfully applied for determination of lisinopril and HCTZ in combined commercial tablets. The results showed that the proposed method was found to be suitable for quantitative determination and the stability study of lisinopril and HCTZ in pharmaceutical samples.

Quantitative determination of fluoxetine in human serum by high performance thin layer chromatography.

A high performance thin layer chromatographic method was developed and validated for the quantification of fluoxetine in human serum. Fluoxetine was extracted by liquid-liquid extraction method with diethyl ether as extraction solvent. Imipramine was used as internal standard. The chromatographic separation was achieved on precoated silica gel F 254 high performance thin layer chromatographic plates using a mixture of toluene/acetic acid glacial (4:5 v/v) as mobile phase. 4-Dimethylamino-azobenzene-4-sulphonyl chloride was used as derivatization reagent. Densitometric detection was done at 272 nm. The method was linear between 12.5 and 87.5 ng/spot, corresponding to 0.05 and 0.35 ng/microL of fluoxetine in human serum after extraction process and applying 25 microL to the chromatographic plates. The method correlation coefficient was 0.999. The intra-assay and inter-assay precisions, expressed as the RSD, were in the range of 0.70-2.01% (n=3) and 0.81-3.90% (n=9), respectively. The LOD was 0.23 ng, and the LOQ was 0.70 ng. The method proved be accurate, with a recovery between 94.75 and 98.95%, with a RSD not higher than 3.61% and was selective for the active principle tested. This method was successfully applied to quantify fluoxetine in patient serum samples. In conclusion, the method is useful for quantitative determination of fluoxetine in human serum.

Instrumental planar chromatographic method for determination of carbamazepine in human serum.

An instrumental planar chromatographic (HPTLC) method for quantification of carbamazepine in human serum was developed using liquid-liquid extraction with dichloromethane, fluorescence activation with perchloric acid 60%/ethanol/water (1:1:1, v/v) and fluorescence detection. Planar chromatographic separation was performed on precoated silica gel F254 HPTLC plates using a mixture of ethyl acetate/toluene/methanol/acetic acid glacial (5:4:0.5:0.5, v/v) as mobile phase. Densitometric detection was done at 366 nm. The method was validated for linearity, precision and accuracy. Linear calibration curves in the range of 3 and 20 ng/microL showed correlation coefficient of 0.998. The intra-assay and inter-assay precision, expressed as the RSD, were in the range of 0.41-1.24% (n = 3) and 2.17-3.17% (n = 9), respectively. The LOD was 0.19 ng, and the LOQ was 0.57 ng. Accuracy, calculated as percentage recovery, was between 98.98 and 101.96%, with a RSD not higher than 1.52%. The method was selective for the active principle tested. In conclusion, the method is useful for quantitative determination of carbamazepine in human serum.

Chemical stability of haloperidol injection by high performance thin-layer chromatography.

The chemical stability of haloperidol lactate injection was studied under different storage conditions by high performance thin-layer chromatography (HPTLC). The study was performed at 25 +/- 2 degrees C and at refrigeration temperature (8 +/- 1 degrees C) in original glass ampoules over 15 days after being opened. The samples tested at 25 +/- 2 degrees C were stored with exposure to and protection from light. Chromatographic separation was achieved on precoated silica gel F 254 HPTLC plates using a mixture of acetone/chloroform/n-butanol/glacial acetic acid/water (5:10:10:2.5:2.5, v/v/v/v/v) as a mobile phase. Quantitative analyses were carried out at a wavelength of 254 nm. The method exhibited adequate linearity (r = 0.999), selectivity, precision (RSD = 1.92%), and accuracy (recoveries from 98.59 to 101.90%). The concentrations of all samples remained greater than or 90% of the original concentration. Haloperidol lactate injection was chemically stable under all conditions studied over 15 days.

Validated liquid chromatographic method for quantitative determination of allicin in garlic powder and tablets.

In the present study, an RP high performance liquid chromatographic method was developed and validated for the determination of allicin in garlic powder and tablets. Chromatographic separation was carried out on an RP-18(e )column (125 mm x 4 mm), using a mobile phase, consisting of methanol-water (50:50 v/v), at a flow rate of 0.5 mL/min and UV detection at 220 nm. Ethylparaben was used as the internal standard. The assay was linear for allicin concentrations of 5.0-60.0 microg/mL. The RSD for precision was <6.14%. The accuracy was above 89.11%. The detection and quantification limits were 0.27 and 0.81 microg/mL, respectively. This method was used to quantify allicin in garlic powder samples. The results showed that the method described here is useful for the determination of allicin in garlic powder and tablets.

Quantitative determination of L-DOPA in tablets by high performance thin layer chromatography.

A densitometric high performance thin-layer chromatographic (HPTLC) method was developed and validated for quantitative analysis of L-DOPA in tablets. Chromatographic separation was achieved on precoated silica gel F 254 HPTLC plates using a mixture of acetone-chloroform-n-butanol-acetic acid glacial-water (60:40:40:40:35 v/v/v/v/v) as mobile phase. Quantitative analysis was carried out at a wavelength of 497 nm. The method was linear between 100 and 500 ng/microL, with a correlation coefficient of 0.999. The intra-assay variation was between 0.26 and 0.65% and the interassay was between 0.52 and 2.04%. The detection limit was 1.12 ng/microL, and the quantification limit was 3.29 ng/microL. The accuracy ranged from 100.40 to 101.09%, with a CV not higher than 1.40%. The method was successfully applied to quantify L-DOPA in real pharmaceutical samples, including the comparison with HPLC measurements. The method was fast, specific, with a good precision, and accurate for the quantitative determination of L-DOPA in tablets.

Chemical stability of midazolam injection by high performance liquid chromatography.

The chemical stability of midazolam hydrochloride injection, undiluted or diluted with dextrose sterile solution, was studied at different storage conditions by LC. The study was performed at room temperature (23 +/- 2 degrees C) under light exposure and light protection, +8 +/- 1 degrees C and -20 +/- 0.5 degrees C, in glass and plastic containers over 14 days with midazolam hydrochloride injection, undiluted or diluted with 5% dextrose sterile solution. Chromatographic separation was carried out on a RP-18(e) column, using a mobile phase consisting of ACN-phosphate buffer (pH 3.3; 0.1 M) (30:70 v/v) at a flow rate of 1.0 mL/min and UV detection at 220 nm. The concentrations of all samples remained greater than 90% of the original concentration. The chromatographic assay exhibited an adequate linearity (r(2) >0.999), selectivity, precision (RSD <3.1), and accuracy (recoveries from 100.46 to 101.40%). Injectable midazolam hydrochloride was chemically stable in all conditions that were studied.

Quantitative determination of clozapine in serum by instrumental planar chromatography.

An instrumental planar chromatographic (HPTLC) method for quantitative analysis of clozapine in human serum was developed and validated. Clozapine was extracted with n-hexane-isoamyl alcohol (75:25 v/v). The chromatographic separation was achieved on precoated silica gel F 254 HPTLC plates using a mixture of chloroform and methanol (9:1 v/v) as mobile phase. Quantitative analyses were carried out by densitometry at a wavelength of 290 nm. The method was linear between 10 and 100 ng/spot, corresponding to 0.10 and 1.00 ng/microL of clozapine in human serum after extraction process and applying 10 microL to the chromatographic plates. The method correlation coefficient was 0.999. The intra-assay variation was between 2.10 and 3.33% (n = 5) and the interassay was between 2.67 and 4.44% (n = 9). The detection limit was 0.03 ng/microL, and the quantification limit was 0.05 ng/microL. The method proved to be accurate, with a recovery between 97.00 and 99.00%, with an RSD not higher than 7.22%, and was selective for the active principle tested. This method was successfully applied to quantify clozapine in patient serum samples. In conclusion, the method is useful for the quantitative determination of clozapine in serum.

Quantitative determination of haloperidol in tablets by high performance thin-layer chromatography.

A densitometric high performance thin-layer chromatography (HPTLC) method was developed and validated for the quantitative analysis of haloperidol in tablets. Chromatographic separation was achieved on precoated silica gel F 254 HPTLC plates using a mixture of acetone/chloroform/n-butanol/acetic acid glacial/water (5:10:10:2.5:2.5 v/v/v/v/v) as the mobile phase. Quantitative analysis was carried out at a wavelength of 254 nm. The method was linear in the 10-100 ng/microL range, with a determination coefficient of 0.999. The coefficients of variation for precision were not higher than 2.35%. The detection limit was 0.89 ng/microL, and the quantification limit was 2.71 ng/microL. The accuracy ranged from 97.76 to 100.33%, with a CV not higher than 4.50%. This method was successfully applied to quantify haloperidol in real pharmaceutical samples, including the comparison with HPLC measurements. The method was fast, specific, with a good precision and accuracy for the quantitative determination of haloperidol in tablets.