Rapid High-performance Liquid Chromatographic Method Research Articles

Stability Indicating HPLC Method for In-vitro Determination of Pantoprazole Sodium and its Degradation Products in Simulated Gastric and Intestinal Fluids

Background: A high-performance liquid chromatography (HPLC) method was developed for the determination of Pantoprazole Sodium (PPZ) in the presence of its degradation products. The degradation of PPZ was studied in simulated intestinal fluid (SIF) and simulated gastric fluids (SGF) in various temperature conditions. Aim: This study aimed to establish a simple, sensitive, and rapid RP HPLC method for in-vitro determination of Pantoprazole Sodium and its degradation products in simulated gastric and intestinal fluids. Objective: Pantoprazole is acid labile drug. In order to determine pantoprazole in various oral dosage forms, the stability-indicating assay of PPZ was performed in phosphate buffer (pH 6.8) representing simulated intestinal fluid (SIF) and in 0.1 molars (M) Hydrochloric acid (HCl) as simulated gastric fluid (SGF) at two different temperature conditions, i.e., 25°C and 0°C, respectively. Method: Pantoprazole sodium was obtained from the Akums laboratory in Haridwar. The analysis was performed by high-performance liquid chromatography (HPLC), Shimadzu, equipped with two LC-10 AD VP solvent-delivery modules, a SPD-10A UV–-visible detector, and a manual injector valve with 20 μL sample loop. Phenomenex ODS analytical column (150 mm × 4.6 mm i.d., 5 μm particles) was done under reversed-phase partition chromatographic conditions. The mobile phase was phosphate buffer and acetonitrile (ACN) of pH 7.4, respectively, optimized in a 70:30 (v/v) ratio followed by filtration through a 0.45 μm membrane filter and degassed by ultrasonicator before use. The mobile phase was delivered at the flow rate of 2 mL/min. The various parameters, such as linearity, accuracy and precision of the analytical method, were studied. Result: The standard curve of PPZ was linear (R2>0.99) over the concentration range of 5-30 μg/mL, and the relative standard deviation (RSD) values for intra-day and inter-day variations were in the range of 1.0-1.8%. The range of RSD was within ±2. Conclusion: The stability of PPZ in aqueous solution was pH dependent. The rate of degradation increases with decreasing pH. The pH stability of pantoprazole was studied at the above-mentioned temperature conditions. The PPZ peaks were analyzed by comparing them with fresh samples and were stable in SIF solution after 24 hours elapsed time at pH 6.8. The obtained degraded peaks in SGF (pH 1) were successfully separated from the PPZ.

A Simple and Rapid High-Performance Liquid Chromatography Method for Preparation and Content Detection of the Mainly Numbing Taste Substances of Zanthoxylum bungeanum Maxim.

As the characteristic numbing taste substances, hydroxyl-α-sanshool (HAS) and hydroxyl-β-sanshool (HBS) were considered vital indicators to evaluate the quality of Zanthoxylum bungeanum Maxim. However, it is very difficult to obtain their high-purity monomers individually, as the only difference between HAS and HBS is that C-6 cis-trans isomerism. In our study, a simple and rapid Ag +-HPLC method was developed to pure the standard chemicals of Z. bungeanum with numbing taste, and 1H NMR and 13C NMR were employed to determine the purity and structure. Moreover, an HPLC method was established to determine the content of numbing taste components of 16 varieties of Z. bungeanum from different regions. The analytical methods were validated for accuracy, precision, and linearity, respectively. The validated method was accurate (spiked recoveries 0.94-1.10), precise in terms of peak area (intra-day RSDs <1.25% and inter-day RSDs <1.61%), and linear (r2 ≥ 0.999). It was found that there were significant differences in the content of HAS and HBS among different types of Z. bungeanum, with HAS content ranging from 60.06 ± 1.14 to 164.13 ± 3.28mg/g and HBS ranging from 7.81 ± 0.36 to 21.11 ± 0.75mg/g. The RSDs of HAS range were 1.73-3.80% and that of HBS range 2.03-4.73% (RSDs ≤5%), which indicated that the measurements of HAS and HBS were reliable.

Determination of ATP-related compounds by HPLC to study the effect of cell-free supernatants of Lactiplantibacillus plantarum on the shelf life of sliced dry-cured ham

This research aimed to study the evolution of ATP-related compounds in dry-cured ham and to assess their suitability as chemical markers of food contamination. A rapid high-performance liquid chromatography (HPLC) method was developed for the analysis of five ATP-related compounds namely, ATP, ADP, AMP, hypoxanthine, and Ino in sliced dry-cured ham. Moreover, a positive correlation between ATP content and microbial load was found in ham during storage. In addition, the method developed herein was employed to quantify ATP-related compounds in sliced dry-cured ham wrapped in a novel antibacterial packaging film containing the cell-free supernatant (CFS) of a probiotic Lactiplantibacillus plantarum strain. The contents of ATP-related compounds in ham samples wrapped in the antibacterial packaging film were lower than in control samples during the 7 days of storage (181 vs 269 mg/kg on day 2; 247 vs 286 mg/kg on day 5; 272 vs 297 mg/kg on day 7). Thus, the evaluated CFS could be considered in packaging material applications for the preservation of sliced ham. This study presents an effective method to assess the quality of sliced ham, which might also contribute to the adoption of active packaging in the food industry.

Simple and Rapid High-Performance Liquid Chromatography Method for Simultaneous Determination of Picloram and 2,4-D in Pesticide Formulations

Picloram and 2,4-D are systemic herbicides used to control a wide range of broad-leaved weeds and post-emergence annual and perennial broad-leaved weeds, respectively. The use of plant protection products containing Picloram and 2,4-D necessitates the development of analytical methods, useful for the laboratories focused on control, for monitoring. In this study, we designed and validated an analytical method for the rapid determination of picloram and 2,4-D by HPLC-DAD. The method involves the extraction of the substances by sonication of the sample with methanol, followed by dilution in acetonitrile, and direct injection on a liquid chromatography system, based on the use of a Gemini C18 column. We used an isocratic mobile elution consisting of acetonitrile and water acidified 1% with H3PO4 (50:50, v/v). We validated the proposed method, which demonstrated linearity within the concentration range of 0.01–0.028 mg/mL for picloram and 2,4-D, with a correlation coefficient (R2) of 0.9993 for picloram and 0.9999 for 2,4-D. We considered precision, repeatability and selectivity in the validation. The repeatability of the method expressed as percent of relative standard deviation (%RSD) was lower than 1% for both substances. The proposed method is suitable for the simultaneous determination of picloram and 2,4-D in pesticide formulations.

Effect of bifenthrin application at different maturity stages on its dissipation and residues in kumquat (Citrus japonica) and dietary intake risk assessment.

Bifenthrin is a pyrethroid pesticide widely used on kumquats, but the residues in the peel and pulp after bifenthrin application at different maturity stages of kumquats have not been evaluated. This study developed a simple and rapid high-performance liquid chromatography (HPLC) method for the quantitative analysis of bifenthrin residues in whole fruit, kumquat peel, kumquat pulp, and soil. The results showed that regardless of whether bifenthrin was applied one or three times during the near-mature period, the half-lives of the fruit peel and fruit pulp were longer than those in the immature period. Kumquat fruit residues decreased with time at both maturity levels. The residues of bifenthrin in near-mature fruit exceeded the MRL in Guangxi and Fujian 14days after the three applications of bifenthrin, suggesting that this issue should be focused on in kumquat production and supervision. However, for bifenthrin application in either the near-mature or the immature fruit period, the calculated risks for chronic dietary intake of kumquat were well below 100%. The data demonstrate that the chronic dietary intake risk of bifenthrin through kumquat consumption is low and within acceptable limits. These results provide a reference and risk assessment data for the safe and rational use of bifenthrin insecticides.

Two different spectrophotometric methods for simultaneous determination of binary mixture of atenolol and amlodipine in commercial formulation

Two different spectrophotometric methods for simultaneous determination of binary mixture of atenolol and amlodipine in commercial formulation

STABILITY INDICATING HPLC METHOD DEVELOPMENT AND VALIDATION FOR SIMULTANEOUS ESTIMATION OF LAMIVUDINE AND DOLUTEGRAVIR IN BULK AND TABLET DOSAGE FORM

A rapid high-performance liquid chromatographic method has been developed and validated for quantification of lamivudine and dolutegravir, used to manage HIV infections. Lamivudine and dolutegravir are separated as symmetrical peaks on the analytical column Inertsil ODS, 150 mm x 4.6 mm, 5.0 µm using 50 % acetonitrile and 50 % triethylamine buffer as mobile phase and detected by photo diode array detector at wave length 250 nm. The total chromatographic runtime is 6.0 min with retention times for lamivudine and dolutegravir at 2.457 and 3.888 min, respectively. The method was validated according to ICH guidelines and linear calibration curves were obtained across a range of 6.01-90.15 µg mL-1 and 1.01 -15.15 µg mL-1 for lamivudine and dolutegravir, a correlation coefficient of R2 0.999. Tablets containing lamivudine and dolutegravir were subjected to acid hydrolysis, alkali hydrolysis, oxidising agent, reducing agent, heat and UV light at two variable conditions and the drugs peaks are well resolved. This developed method can be used routinely for the determination of lamivudine and dolutegravir in bulk and tablet dosage form.

Determination of Alpha-Lipoic Acid in a Nutritional Supplement Using High Performance Liquid Chromatography

Alpha lipoic acid has the ability to react and neutralize reactive oxygen species (ROS) such as superoxide radicals, simple oxygen, hydroxyl radicals, hypochlorous acid and peroxyl radicals. A rapid high-performance liquid chromatographic method for determination of lipoic acid in a nutritional supplement was developed. The method involved sample preparation and the mobile phase comprised of 50 mM disodium hydrogen phosphate buffer (pH 2.5 adjusted with 1 M H3PO4): acetonitrile in the ratio of 50:50. The separation was done using a C18 column (150 mm) and detection was carried out using UV detection at 201 nm. The assay was found to be linear in the range of 1.56 - 50 μg/mL with the correlation coefficient of 0.9997. Method precision was determined while LOD was 0.05 μg/mL and LOQ 0.15 μg/mL. The chromatographic peak LA retention time was 6 min.

Development of a Validated Stability-Indicating HPLC Method for Vinpocetine in the Presence of Potential Impurities in Tablet Dosage Form by Multiresponse Optimization.

Vinpocetine has been prescribed for the treatment of ischemic brain diseases for many years. The drug, which has side effects such as headache, flushing, and decreased blood pressure, is not found in nature, but it can be synthesized by several approaches. A simple, rapid, selective, stability-indicating high-performance liquid chromatographic (HPLC) method was developed for the simultaneous estimation of vinpocetine and their potential impurities in a tablet formulation. Optimum HPLC conditions were tried to be determined by a statistical experimental design method. The proposed method was validated as per the ICH guidelines. Stress study was used to demonstrate the stability-indicating ability of the developed method in the quantification of vinpocetine and potential impurities within the same run. According to multiresponse optimization using the Derringer's desirability function, the mobile phase consisted of an acetonitrile-phosphate buffer (pH 6.0) in the ratio of 65:35 (v/v) at a flow rate of 1.7 mL/min. Significant degradations were observed for the drug product under acid hydrolysis and alkali hydrolysis. The new method showed reasonable detection and quantification limits with good selectivity, precision, linearity, and recovery. These validation results have shown that this method is suitable for quantitative determination of vinpocetine and its impurities in quality control laboratories. A reliable and rapid HPLC method optimized with response surface methodology and multiresponse optimization based on Derringer's desirability function was developed for the simultaneous analysis of vinpocetine and its impurities in a tablet formulation.

Ceftaroline fosamil: development a rapid HPLC method indicating stability and bioassay for determination in pharmaceutical formulation, stability and cytotoxicity studies

The present study reports the development and validation of a microbiological assay. To assess this methodology, the method was developed and validated for the quantification of CEF by high performance liquid chromatography (HPLC). The validation of the microbial assay by diffusion method in 3x3 cylinder agar presented showed satisfactory results as to specificity, linearity in the range of 2.0 - 8.0 μg.mL-1, precision (109.42 %), accuracy (102.3 %), and robustness. The development and validation of the method by HPLC were evaluated according to specificity, linearity, precision, accuracy and robustness. A high performance liquid chromatography from Shimadzu with Agilent® C18 column, mobile phase (water with triethylamine 1.0 % pH 5.0: acetonitrile 87:13 v/v was used in the chromatographic method. The validated microbiological and chromatographic methods were compared statistically and there was no significant difference between them when compared by Student's t-test. In the preliminary stability study, it was found stable in acid hydrolysis (0.1M) and UVA light in the period evaluated, and unstable against thermal degradation (40 and 60 °C), oxidative with hydrogen peroxide, basic in NaOH (0.1 M and 0.01M) and UVC light. Samples exposed to UVC light and thermal degradation at 60°C showed degradation kinetics following zero order and second order, respectively. The cytotoxicity assay showed no difference between the normal condition and the sample submitted to forced degradation, suggesting that the possible degradation products formed did not change the result. The methods developed did not present a significant difference, therefore, they are interchangeable, and so can be used for routine quality control analysis.

Development of a rapid and reliable high-performance liquid chromatography method for determination of water-soluble vitamins in veterinary feed premix.

Background and Aim:Determination of trace amounts of vitamins in multi-component feed premix is a troublesome analytical procedure. In this study, a simple and rapid high-performance liquid chromatography (HPLC) method was developed and validated for the concurrent detection and quantitation of four water-soluble vitamins such as thiamine, riboflavin, pyridoxine, and cyanocobalamin in veterinary feed premixes.Materials and Methods:The chromatographic separation of the vitamins was carried out at 35°C temperature on a reversed-phase C18 column using a gradient pump mode. Mobile phase constituents were solvent (a): 25 mM Potassium dihydrogen phosphate and 5 mM sodium hexanesulfonate in deionized water having pH-4.0 and solvent and (b) 5 mM sodium hexanesulfonate in methanol. Detection was performed with HPLC ultraviolet/visible detection set at 278 and 361 nm wavelength in two different channels. The flow rate was 1.2 mL/min and the total run time was 25 min.Results:The method was validated according to the International Conference on Harmonization and Food and Drug Administration guidelines and acceptance criteria for system suitability, precision, linearity, and recovery were met in all cases. The relative standard deviation for system suitability and precision was <2% for all vitamins. The linearity of the calibration curves was excellent (R2>0.999) at concentration of 5, 10, 15, 20, 25, and 30 μg/mL for all vitamins. The limits of detection values were 0.0125, 0.0017, 0.0064, and 0.0065 μg/mL for thiamine, riboflavin, pyridoxine, and cyanocobalamin, respectively, and the limits of quantification values were 0.0378, 0.0051, 0.0213, and 0.0198 μg/mL for thiamine, riboflavin, pyridoxine, and cyanocobalamin, respectively. The recovery percentages ranged from 88% to 115%.Conclusion:The overall parameters of the proposed method met the validation criteria and this method could be a highly desirable technique for routine analysis of water-soluble vitamins in veterinary feed premix.

Determination of Tedizolid in Bacterial Growth Medium Mueller-Hinton Broth by High-Performance Liquid Chromatography and Its Application to an In Vitro Study in the Hollow-Fiber Infection Model

Pharmacokinetic/pharmacodynamic (PKPD) studies of anti-infectives are frequently performed in in vitro infection models where accurate quantification of antibiotic concentrations in bacterial growth media is crucial to establish PK/PD relationships. Here, a sensitive and rapid high-performance liquid chromatography (HPLC) method was developed to quantify tedizolid (TDZ) in the bacterial growth medium Mueller-Hinton broth (MHB). Matrix components were separated by direct protein precipitation with methanol (1:1). The chromatographic separation was carried out in a Dionex Ultimate 3000 HPLC system using an Accucore® C-18 RPMS HPLC column (2.6 µm, 100 × 2.1 mm) using isocratic elution with 25% acetonitrile and 75% of 0.1% formic acid. The lower limit of quantification was 0.03 mg/L when measured at 300 nm. Following relevant European Medicine Agency guidelines, the method was successfully validated for linearity, selectivity, recovery, inter- and intra-day precision, and accuracy and stability. When applied to in vitro PKPD studies, the method successfully quantified a range of TDZ concentration (Cmin, 0.09-Cmax, 0.65 mg/L) in MHB. The analyzed concentrations were in line with the planned PK profiles. The application of the developed method to quantify TDZ in MHB in in vitro PKPD studies is warranted.

Concurrent estimation of lamivudine, tenofovir disoproxil fumarate, and efavirenz in blended mixture and triple combination tablet formulation by a new stability indicating RP-HPLC method

BackgroundAn easy, defined, rapid, and accurate reverse phase high-performance liquid chromatography method was developed and subsequently validated for the concurrent estimation of lamivudine, efavirenz, and tenofovir disoproxil fumarate in their pure blend and combined tablet formulation. An efficient and appropriate separation of the three analytes was attained with Zorbax eclipse XDB-Phenyl column, with a mobile phase of methanol: buffer (0.1% v/v formic acid in water) (73:27 v/v) at a flow rate of 1mL/min and isocratic elution by using 260nm as detection wavelength. Equal ratio of acetonitrile and water was used as diluent.ResultsThe retention times of lamivudine, tenofovir disoproxil fumarate, and efavirenz were found at 2.6, 4.4, and 5.9 min respectively. The linear response for lamivudine, tenofovir disoproxil fumarate, and efavirenz was in the range of 15.0–45.0μg/mL, 15.0–45.0μg/mL, and 20.0–60.0 μg/mL respectively. The method validation was done in accordance to ICH guidelines and all validation parameters in compliance with ICH standards. The degradants produced by stress testing were well resolved from the peaks of active analytes, which stipulates the stability-indicating property of the method.ConclusionThe method has the ability to separate lamivudine, efavirenz, and tenofovir disoproxil fumarate concurrently in blended powder and their combined tablet. All degradants produced by application of stress conditions were separated with high resolution and determined with good sensitivity that ensures the stability-indicating property of the method. Thus, the projected method has high probability to adopt in the pharmaceutical industrial sector.

The Differences in the Flavan-3-ol and Procyanidin Contents of the Japanese 'Fuji' and 'Orin' Apples Using a Rapid Quantitative High-Performance Liquid Chromatography Method: Estimation of the Japanese Intake of Flavan-3-ols and Procyanidins from Apple as Case Study.

Previously, we reported that apple polyphenols and their major active compounds, the flavan-3-ols and the procyanidins, can result in various health benefits in animals and humans, according to clinical studies. Here, we developed a rapid method for quantifying flavan-3-ols and procyanidins using high-performance liquid chromatography with fluorescence detection, where we investigated the amounts of flavan-3-ols and procyanidins in the Japanese major apple production centre, the Aomori Prefecture, from 2016 to 2018. The non-bagged ‘Fuji (n = 609)’, the bagged ‘Fuji (n = 1101)’, and the ‘Orin (n = 504)’ apples were evaluated in terms of their differences in flavan-3-ols and procyanidins based on apple variety and the controlled atmosphere storage. The bagging treatments of the ‘Fuji’ apples resulted in significantly higher concentrations of procyanidins, while changes in flavan-3-ols concentrations were not clearly observed by treatment. In addition, ‘Orin’ had a significantly higher concentration of procyanidins than that of ‘Fuji’. In contrast, the controlled atmosphere storage hardly caused any changes in the flavan-3-ol and procyanidin contents. Hence, we present the concentrations of flavan-3-ols and procyanidins in major Japanese apples using the rapid high-performance liquid chromatography method with fluorescence detection.

Rapid and Simple Reversed-Phase High-Performance Liquid Chromatography (RP-HPLC) Method for Simultaneous Quantifications of Triazole Antifungals in Human Serum.

To develop and validate a one-step, rapid and simple reversed-phase high-performance liquid chromatography (HPLC)-based protocol for the simultaneous measurement of voriconazole (VCZ), posaconazole (POSA), itraconazole (ITC) in serum/plasma. Calibration standards (CS) and quality control samples were prepared in drug-free serum by spiking with the triazoles at different concentrations. HPLC was performed with C18 column, isocratic mobile phase after extraction with cold acetonitrile. The standardized method was tested in 2693 patients' serum/plasma samples. Linearity of CS for ITC, VCZ and POSA was proportional to the nominal concentration (correlation coefficient > 0.999). Limit of detection (mg/L) for ITC, VCZ and POSA was 0.25, 0.25 and 0.125, respectively. The lower limit of quantification (mg/L) for ITC, VCZ and POSA was 0.5, 0.5 and 0.25, respectively. Precision and accuracy were in acceptable range with 100% average percentage recovery. No interferences from endogenous substances and other antimicrobial compounds were noted. In clinical samples, the therapeutic range achieved for VCZ was 39.9%. Whereas, 61.1% and 44% of samples with ITC and POSA, respectively, were in the sub-therapeutic range. We developed a rapid and simple HPLC method to quantify common triazoles in a single chromatographic run allowing simultaneous measurement of different antifungals in a small volume of serum/plasma. Thus, therapeutic drug monitoring requests can be processed in one run without changing the protocol parameters, column or column conditioning thereby improving turnaround time.

Extraction and analysis of oleanolic acid and ursolic acid from apple processing waste materials using ultrasound-assisted extraction technique combined with high performance liquid chromatography

The aim of the present study was to develop a is simple, effective, eco-friendly, reproducible and high-yield two-stage ultrasound-assisted extraction (UAE) procedure combined with quantitative determination high performance liquid chromatographic (HPLC) method for obtaining isomeric triterpene acids - oleanolic acid (OA) and ursolic acid (UA) in the crystalline dried powdered form from apple processing agro-industrial waste material. A rapid, sensitive and specific HPLC method was developed and validated with respect to robustness, specificity, linearity-range, accuracy, precision and sensitivity. The effect of the nature and the volume of the extraction solvent, the extraction time and the sample size on the extraction efficiency were investigated. The optimal conditions for high-yield extraction were found.

Rapid High-Performance Liquid Chromatography Method for Levodopa Quantitation at Low UV Wavelength: Application of Pharmacokinetics Study in Rat Following Intranasal Delivery.

Levodopa is widely administered orally in clinical treatment of Parkinson's disease; however, due to levodopa various oral absorption and low bioavailability, intranasal delivery seems to be a suitable alternative route of administration. Pluronic F-127 is a thermosensitive polymer, which can form gel at nasal cavity temperature and increase drug residence time. In this study, a rapid High Performance Liquid Chromatography (HPLC) method was validated in presence of internal standard to determine pharmacokinetic parameters following levodopa administration to rats in three different intravenous solution, intranasal solution and intranasal thermosensitive gel groups. A precised (96.7%) and accurate (95.0%) HPLC method was validated at low UltraViolet (UV) wavelength of 208nm that showed limit of detection and limit of quantitation of 59 and 177ng/mL, respectively. Specificity results showed no interference for levodopa with endogenous serum materials, and serum extraction efficacy was 93%. Pharmacokinetic parameters including bioavailability of 75 and 85% with mean residence time of 78 and 94min were estimated for intranasal solution and thermosensitive gel using the validated HPLC method, which indicated that levodopa nasal gel may be a good alternative with appropriate pharmacokinetic outcome. Therefore, the validated levodopa HPLC analysis method at low UV wavelength was efficiently applied in pharmacokinetic study.

Method Development and Validation of Metoprolol and Felodipine by using RP-HPLC in Bulk and Pharmaceutical Dosage Form

The main objective of this research is to develop and validate a simple, specific, precise, sensitive, cost effective and rapid Reversed-Phase High-Performance Liquid Chromatographic (RP-HPLC) method for simultaneous quantification of Felodipine and Metoprolol in bulk and pharmaceutical dosage forms. The separation of the analytes were carried out on a X-bridge phenyl column with a moving phase composed of 0.1 % Tri ethyl amine: acetonitrile (30:70 v/v) delivered at a stream of 1.0 ml/min, and separation has been observed by UV detector, at a detection wavelength of 235 nm. This method was proven to be linear over a concentration limit of 10-150 µg/ml for Metoprolol, 2-30 µg/ml for Felodipine with correlation coefficient of 0.999. The retention time of Metoprolol and Felodipine were 2.936, 4.535 minutes respectively. To separate Metoprolol and Felodipine peaks a run time of 8 min. was used. The validation results were in good agreement with acceptable limits. RSD values which are less than 2.0 % indicating the accuracy and precision of this method. Hence it was evident that the proposed method was said to be a suitable one for the regular analysis and quality control of pharmaceutical preparations which contain these active drugs either individually or in combination.

Characterization, purity assessment, and preparation of liposomal formulation of 2,4,6-trihydroxygeranylacetophenone

Purpose: To prepare, characterize, and determine the purity of 2,4,6-trihydroxygeranylacetophenone (tHGA), and also to develop and characterize a liposomal formulation of tHGA to overcome its poor water solubility.&#x0D; Methods: The tHGA was synthesized and then purified in two steps using two types of column chromatography separation techniques. The compound was characterized using different analytical techniques, while the purity of tHGA was determined by quantitative-nuclear magnetic resonance (qNMR). Proliposomes method was developed to produce liposome-encapsulated tHGA which was characterized based on particle size, polydispersity, stability, and encapsulation efficiency. A selective and rapid high-performance liquid chromatography (HPLC) method was developed and validated to quantify tHGA in a liposomal formulation in order to evaluate the encapsulation efficiency.&#x0D; Results: The tHGA was successfully prepared and characterized with 98.4 % purity. A simple and reproducible proliposomes method was successfully developed to produce liposome-encapsulated tHGA. The liposomal formulation exhibited excellent encapsulation efficiency (90.4 %). This formulation also yielded a homogenous liposome population (polydispersity index = 0.39) with a small particle size (250.8 nm). The prepared liposome-encapsulated tHGA was stable at refrigerated temperature (4 ºC) for at least four weeks. The developed HPLC method showed good linearity over the range of 10 to 500 μg/mL with high precision and accuracy.&#x0D; Conclusion: The compound produced has a high purity which can be used as an analytical reference standard. The developed formulation is effective for dissolving and entrapping a high amount of tHGA which helps to overcome its poor solubility.&#x0D; Keywords: Liposomes, Proliposomes, Trihydroxygeranylacetophenone, tHGA, Spectroscopic characterization, Poor solubility

A Validated Liquid Chromatographic Method for Berberine Analysis in Tissue and Application.

Simple and rapid high-performance liquid chromatography methods were developed for the determination of berberine (BB) in various rat tissues so as to evaluate a P-gp inhibitor, glycyrrhetinic acid (GA), on BB's oral bioavailability. Acetonitrile was used to extract BB from tissues and showed different extraction recoveries in diverse tissues. The intra- and interday precision and accuracy were less than 10%. Long-term stability, pre (post) -preparative stability, and freeze-thaw stability were evaluated, and the results showed it could meet the need of this study. The proposed methods were subsequently applied to investigate the possible drug-drug interaction of GA and BB in vivo from the aspect of tissue distribution. The results showed that no significant difference was found between the group of low dose and high dose at the same time point. The tissue distributions show a saturated model, i.e., the content of BB in tissue tends to be constant while its dose is more than 200 mg/kg. Besides, the contents of BB ranged from high to low according to the order of the liver, kidney, and spleen. The BB content in the liver is especially high as compared to other tissues.