High-performance Liquid Chromatographic Method For Analysis Research Articles

Development and Validation of an HPLC Analytical Method to Determine 6-Merpactopurine Concentration in Oral Suspension

Background: The 6-mercaptopurine is an active ingredient used to treat certain types of leukemia. This drug is an immunosuppressive and antineoplastic agent that belongs to the thiopurine class. In Brazil, 6-MP is currently available only in the form of 50 mg tablets, sold as Purinethol® and manufactured by Glaxo Smith Kline. The lack of the liquid formulation’s production impedes treatment, assuming that one of its advantages is through its applicability in pediatric patients, who show the highest incidence among others. Objective: The purpose of this work was to evaluate the development and application of a reversed phase high performance liquid chromatography (HPLC) method using an Agilent 1220 Infinity® G4294B chromatograph with photodiode array detector. Methods: HPLC assays were performed on an Eclipse plus® C18 column (4.6 x 150 mm, 3.5 μm particle size) using a gradient mode mixture of acetonitrile and aqueous acetic acid solution as a mobile phase, with a flow of 1 mL.min-1 and detection at 324 nm. The method was validated by determining its selectivity, linearity, precision, accuracy, and robustness. Results: Retention time for 6-mercaptopurine was 5.12 minutes. The detector’s response was linear at concentrations from 1.6 to 2.4 μg/mL. The results of the method’s accuracy evaluation showed mean recovery of the amount of substance added to the samples of between 99.88 and 100.5%. For precision, repeatability and intermediate precision were evaluated. The repeatability showed a standard deviation of 0.0737. The intermediate precision was assessed on three different. For three days of the studies, the values of the standard deviations were less than 3%, showing repeatability and intermediate precision adequate for the analytical method in question. The limit of detection was determined as 3.6 ng/mL. The limit of quantification was determined as 12 ng/mL. The chromatographic method was robust. Conclusion: The proposed method can be applied to control the quality of 6-MP oral suspension to ensure that the required content is delivered to pediatric oncology patients.

Ultrasonic-Assisted Thymol and Carvacrol Extraction from Za’atar Leaves Using Cold-Pressed Sesame Oil

Thymol and carvacrol found in Origanum syriacum “Za’atar” plant leaves have triggered interest among researchers for their natural antimicrobial and antifungal properties. However, their applications in modern pharmaceutical and cosmetic industries as natural preservatives remain challenging. In this research, extraction of thymol and carvacrol from Za’atar leaves has been investigated using the ultrasonic-assisted method and the use of sesame oil as the primary extraction solvent compared with other vegetable oils including sunflower and olive oils. In addition, a high-performance liquid chromatography (HPLC) analytical method was developed by using a C8 column and 0.05% trifluoroacetic acid as a buffering agent. The method was validated for specificity, linearity, repeatability, accuracy, and robustness for the analysis of the content of the two terpenes thymol and carvacrol in different Za’atar extracts. Using the validated analytical method, thymol and carvacrol content results revealed the best vegetable oil for extraction. Results showed that sesame oil had the highest content of thymol and carvacrol, followed by sunflower oil, and the least amount obtained by using olive oil. A consistent extraction result opens an opportunity for application in the pharmaceutical and cosmetic industries. For this reason, the essential extraction key parameters that influence the final content of thymol and carvacrol were evaluated. The highest impact originated from the quality and volume of sesame oil. Cold-pressed sesame oil resulted in a 23% higher content of thymol and decreased amount of carvacrol. It was found that wetting the Za’atar leaves powder with sesame oil was enough for extraction; any additional sesame oil volume dilutes the extracted sample. The second impact was the Za’atar cultivation conditions; less than 10% difference of thymol and carvacrol content was observed within Za’atar of Hebron origin. Finally, the origin of sesame seeds used for sesame oil production had the least impact.

Development and Validation of an HPLC Method for Analysis of Topotecan in Human Cerebrospinal Fluid and Its Application in Elimination Evaluation of Topotecan after Intraventricular Injection.

Simple SummaryIntrathecal administration of anticancer drugs is an effective strategy to treat meningeal leukemia and lymphoma. Topotecan is an anticancer drug, and its anticancer effect is expected via intrathecal administration. In this study, we developed a method to measure the concentration of topotecan in the cerebrospinal fluid (CSF) for clinical monitoring of personalized medicine. By controlling the unique structural feature of topotecan, a pH-dependent lactone ring-opening/closing reversible reaction, we established a simple high-performance liquid chromatography (HPLC) method to measure the total topotecan concentration in the CSF and confirmed that this method can be applied to clinical samples. In the present situation, wherein the concentrations were monitored, the disappearance of topotecan in the CSF was delayed, and signs of adverse effects were confirmed when a high concentration of topotecan was observed.Intrathecal administration of anticancer drugs is an effective dosage strategy, but the elimination of intraventricular drugs is not uniform in all patients. For safety, a system to evaluate local pharmacokinetics in the ventricles after administration is desired. In this study, we developed a simple and reproducible method to measure topotecan concentration in the cerebrospinal fluid (CSF) and confirmed its clinical applicability. High-performance liquid chromatography (HPLC) analysis was performed using a C18 column to measure the total topotecan concentration in the CSF. Clinical CSF samples were obtained from a 1-year old child with poor CSF absorption and stagnation. The patient received topotecan via an intraventricular subcutaneous reservoir. The HPLC method complied with the validation criteria. The lower limit of quantitation of this method was 0.04 µM. Using the developed method, we could determine the difference in topotecan CSF concentrations at 24 and 48 h after administration. The patient’s topotecan elimination rate was extremely low, and signs of adverse effects were observed at high CSF concentration of topotecan. The developed method could detect the delay in topotecan elimination after intrathecal injection. The findings of this study are valuable for the development of personalized treatments for the intrathecal administration of anticancer drugs.

A Review on Different Analytical Techniques for Determination of DNP Drugs and their Metabolites in Pharmaceutical Formulations

Background: Neuropathy is the most common perplexity of diabetes type 1 and 2. About 50% of diabetic patients develop diabetic neuropathic pain (DNP). At the beginning of diabetic neuropathy, there is a loss of sense, especially in the lower limb, accompanied by pain, and difficulty in movement. Glucose regulation effectively prevents the development of diabetic neuropathy in type 1 diabetic patients, but the consequences in type 2 diabetic patients are more drastic. Introduction: No single treatment exists to prevent or renovate the pain caused by diabetic neuropathy. The drugs used for the treatment of DNP come in various formulations and with different storage conditions. To date, a number of analytical methodologies have been reported for the analysis of DNP drugs. Few reports are published describing analytical methods of single DNP drugs. Methods: The main objective of this review is to compile the different analytical methods developed at UV-Vis (Ultraviolet-visible) spectrophotometer, HPLC (High Performance Liquid Chromatography), and LC-MS (Liquid Chromatography-Mass spectrometry) to identify and quantify the drug content in various formulations, which are used to treat or prevent the diabetic neuropathic pain mainly focusing on γ-aminobutyric acid analogues, anti-depressants, Serotonin Noradrenaline Reuptake Inhibitors (SNRIs), aldose reductase inhibitors, opioids, and dietary supplements. Results and Discussion: We have compiled UV-Vis, HPLC, and Liquid Chromatography-Mass spectrometry analytical methods developed to study the pharmacokinetic profile, quantify drug content, and their metabolites in plasma as well as pharmaceutical formulations. Conclusion: The authors believe that the mentioned studies in the report will help audible readers to select a suitable method for analysis of these drugs and also help researchers to develop a more convenient, fast, and sensitive method for these.

A validated HPLC-UV method for the analysis of phenolic compounds in Brazilian red propolis and Dalbergia ecastaphyllum

Propolis is a natural product produced from the interaction between bees and plants. Brazilian red propolis results from Apis mellifera collection of resins from two plant species, being Dalbergia ecastaphyllum(L.) Taub, Fabaceae, the primary botanical source, containing isoflavonoids and other characteristic phenolic compounds. Several biological activities of Brazilian red propolis and their isolated compounds have been described in the literature. However, to our knowledge, there are no validated analytical methods for the analysis and standardization of products derived from this type of propolis reported in the literature. We developed a reverse-phase high-performance liquid chromatography analytical method for the detection and quantification of nine red propolis chemical markers: liquiritigenin, calycosin, isoliquiritigenin,formononetin, vestitol, neovestitol, medicarpin, biochanin A, and 7-O-methylvestitol, present in Brazilian red propolis extracts and D. ecastaphyllum. The developed method was also applied to the analyses of D. ecastaphyllum samples and seasonal analysis of Brazilian red propolis. Good detection response, linearity, precision, and robustness were obtained by the method, being reliable for the quality control of Brazilian red propolis extracts, raw propolis, plant material, and their derived products. The red propolis chemical markers were present in D. ecastaphyllum stems at lower concentrations. The seasonal analysis of Brazilian red propolis extract showed higher phenolic compound concentration on periods of the rainy season with higher humidity and lower solar radiation.

Uporedna analiza volumetrijske i instrumentalne metode za određivanje sadržaja nitroglicerina u barutu

The major energy components of double-based gunpowder are nitrocellulose (NC) and nitroglycerin (NG). In double-based gunpowder NG is used as a plasticizer and, at the same time, as an energetic component. Since the amount of NG in the gunpowder strongly influences and affects its chemical and mechanical properties or/and characteristics, the study of NG content is of great importance. The aim of this paper is to compare the analytical performances of high-performance liquid chromatography (HPLC) and classic analytical volumetric method for the separation and qualitative determination of nitroglycerine in smokeless gunpowder.

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.

Validation of a reversed-phase high-performance liquid chromatography (RP-HPLC) method for analysis of [11C]Nicotine

Validated analytical methods must be used for accurate and precise determination of identity, purity, strength, and quality of any pharmaceutical dose intended for human administration. Consequently, all analytical methods must be validated per USP and the ICH Q2R1 guidelines to meet the cGMP requirements of the FDA and EMA. A reversed-phase high-performance liquid chromatography analytical method, with <10 min run time, was developed for the analysis of [11C]nicotine. The analytical method was found to be specific, accurate, suitable, robust, precise, and linear for [11C]nicotine, nicotine, and (±) nornicotine in the concentration ranges studied. The LOD and LOQ values were also established.

Ex vivo penetration analysis and anti-inflammatory efficacy of the association of ferulic acid and UV filters

BackgroundUnprotected chronic exposure to ultraviolet (UV) radiation generates many harmful effects to human skin and sunscreens are essential to health, however, traditional products do not provide enough protection against cutaneous oxidative stress, a process amplified by UV radiation. Therefore, the development of multifunctional photoprotective formulations seems to be a more efficacious approach, since these enable the absorption/reflection of UV radiation and maintain the cutaneous homeostasis. ObjectivesIn the present study, ferulic acid (FA), a well-known antioxidant, has been combined with two UV filters, bemotrizinol and ethylhexyl triazone, and the safety and efficacy of this formulation has been assessed combining ex vivo and in vivo methods. MethodsSkin permeation assays were performed by applying the formulation in the volar forearm of participants, after which consecutive samples of the stratum corneum were collected by tape stripping, and the quantification of FA, bemotrizinol and ethylhexyl triazone was performed by high-performance liquid chromatography (HPLC). Also, the FA anti-inflammatory action in combination with the UV filters was probed through a method employing Laser Doppler flowmetry to measure the vasodilatory response to methyl nicotinate topical application. ResultsSkin permeation assay was able to characterize the penetration depth of each substance. It should also be noted that a specific HPLC analytical method was developed in this study to enable the rapid simultaneous quantification of the three substances. Results from Laser Doppler flowmetry showed that the FA was able to mitigate the vasodilatory response. ConclusionsFA proved to be a valuable resource in a multifunction sunscreen, not only providing an increase in the SPF of sunscreens, previously published, but also decreasing the extent of inflammation.

Tablet Formulation of a Synthesized Celecoxib Potassium Salt and Development of a Validated Method for Its Analysis.

Celecoxib is a non-steroidal anti-inflammatory drug (NSAID) and cyclooxygenase-2 (COX-2) inhibitor. It is used for the treatment of rheumatoid arthritis, osteoarthritis, juvenile arthritis, and acute pain. Celecoxib has low systemic bioavailability due to its low water solubility. This study aimed to improve water solubility and dissolution profile by synthesizing a suitable celecoxib potassium salt (celecoxib-K salt). Four celecoxib salts were synthesized, and the solubility of these four salts was determined. Celecoxib- K monohydrate salt was chosen for tablet formulation. A simple and feasible reversed-phase high-performance liquid chromatography (HPLC) method was developed for the analysis of the formulated tablet and then validated according to international guidelines. The dissolution profile, shelf life, and accelerated stability studies on the formulated tablet were conducted. Celecoxib-K monohydrate salt exhibited increased water solubility by more than 140-folds (0.464 mg/ml) compared with celecoxib. The in vitro dissolution profile of the formulated celecoxib-K salt tablet was totally dissolved after 10 min. The developed analytical HPLC method was a reliable and valid method with good linearity, accuracy, and precision. Moreover, it was sensitive, and the limit of detection and quantification (LOD and LOQ) were 0.001 and 0.1 mg/L, respectively. The formulated celecoxib-K monohydrate salt tablet was stable under room temperature and accelerated condition for 60 days. The potassium salt of celecoxib was highly increased, and the formulated tablet of celecoxib-K salt exhibited a good dissolution profile in the water. In addition, the developed HPLC method was valid and reliable for the analysis and quantification of the formulated tablet. The formulated tablet was stable both at room temperature and under stress conditions.

Simultaneous determination of plasma betamethasone disodium phosphate and betamethasone in rabbit by high performance liquid chromatography

Betamethasone disodium phosphate (BDP), a hydrophilic prodrug of betamethasone (BTM), was rapidly converted into betamethasone in blood following intravenous administration. In this study, we established an analytical method of high performance liquid chromatography (HPLC) to simultaneously determine BDP and its free base BTM in plasma samples. The calibration curves demonstrate good linearity (BDP, R2 = 0.99999; BTM, R2 = 0.99997) and reproducibility within a range from 50 ng/mL to 6000 ng/mL. The analytical method was applied to determine the pharmacokinetics of BTM and BDP following intravenous bolus injection of BDP in New Zealand white rabbits (0.4 mg/kg). The determined pharmacokinetic parameters were listed as follows: for BDP, half-life: 13.69 ± 2.70 min (Mean ± SEM, n = 6), clearance: 3.96 ± 0.45 mL/min/kg and distribution volume: 72.9 ± 9.67 mL/kg; for BTM, half-life: 228.58 ± 72.9 min, clearance: 3.50 ± 1.18 mL/min/kg, and distribution volume: 327.57 ± 69.9 mL/kg. The established HPLC analytical method and related pharmacokinetic parameters of BDP and BTM might be potentially applied to use these drug administration in the treatment of respiratory relevant diseases.

Stability characteristics of cannabidiol for the design of pharmacological, biochemical and pharmaceutical studies

Cannabidiol (CBD) is one of the most promising cannabinoids in therapeutics. Nevertheless, the reported stability testing has been carried out with plant extracts and not with CBD as a drug substance. The aim of this work was to evaluate the stability of CBD in solution. A High-Performance Liquid Chromatography (HPLC) analytical method, with CBD in ethanol, was previously validated for these stability studies. The resulting method was linear and proportional in a range of concentrations from 1 to 150 µg CBD/mL, as well as precise. It was also considered suitable to quantify CBD in aqueous medium as reported in accuracy studies. The stability of CBD was influenced by multiple factors. Temperature was one of the most critical parameters, with an activation energy of 92.19KJ/mol. At room temperature, CBD was highly unstable (t95 = 117.13 days). However, at 5 °C it was stable for at least 12 months. CBD was also sensitive to oxidation, with a short t95 of 1.77 days in oxidizing environments, as well as to light. The photolytic reaction seems to be oxidative. The solvent influences CBD stability, and the latter is more stable in ethanol than in aqueous medium. In fact, in simulated physiological conditions (pH 7.4 and 37 °C) 10% of CBD was degraded within 24 h. These studies indicate that CBD is highly unstable, and this should be taken into account in the development of in vitro and in vivo studies of CBD activity and in the pharmaceutical development of dosage forms.

A Herb-drug interaction study: Screen the inhibitory effects of Insulin plant extract on rat liver CYP2D6 isoenzyme upon concurrent administration of Aripiprazole

Aripiprazole belongs to the atypical antipsychotic category of drug. Cytochrome2D6 (CYP2D6) is one of the prominent enzymes that play a key role in the metabolism of Aripiprazole and further formation of an active metabolite, Dehydroaripiprazole takes place. Patients under the treatment with this potent moiety have been reported with the high blood glucose level as a side effect. In addition to this, literature suggests that the leaves of Insulin plant (Costus igneus) are usually administered by diabetic patients (2-3 times) to manage the sugar level without concerning to the physicians. There might be probability while concurrent administration of (Aripiprazole and Insulin plant leaves), leaves inhibit the enzyme and ultimately Dehydroaripiprazole exhibit poor pharmacological action. Hence, the present work was done to investigate the inhibitory effect of Insulin plant extract (IPE) on CYP2D6, with the co-administration of Aripiprazole (to examine the changes in a metabolite of Aripiprazole). In order to carry out this protocol firstly, IPE was prepared by the successive extraction method. Methanolic extract of Insulin plant was found enriched with the Quercetin, which was used as a marker to carry out this study. Presence of Quercetin was confirmed with the Ultra-violet spectroscopy (UV) and High-performance liquid chromatography (HPLC) analytical methods. Characterization of Aripiprazole was done with the help of different analytical tools such as: HPLC, melting point, and UV. Aripiprazole alone and with the several dilutions of IPE were incubated using isolated rat liver microsome (RLM) and analyzed using HPLC. HPLC data demonstrated that the, mixture of IPE+Aripiprazole (herb and drug in liver microsomes), in comparison to Aripiprazole+RLM (alone drug in liver microsomes) has not shown any significant inhibition of the enzyme, and inhibitory concentration (IC50) value found to be 4.49µg/ml. Therefore this study concluded that IPE has shown safe results even at the highest clinical dose after oral administration i.e., 20-1000µg/ml and did not show any significant CYP2D6 inhibition. Nevertheless, to confirm these observations, inclusion of in vivo studies will be advantageous. As per our knowledge, this is the first attempt made on the detection of Herb- Drug interactions (HDI’S) between Insulin plant and Aripiprazole.&#x0D;

Development and optimization of a stability-indicating chromatographic method for verapamil hydrochloride and its impurities in tablets using an analytical quality by design (AQbD) approach

Development and optimization of analytical methods for quantifying verapamil hydrochloride in its twelve impurities is a challenge for analytical chemists and pharmacists. The aim of this paper was to apply the analytical quality by design (AQbD) and design of experiments (DoE) approaches in the development of a robust, low-cost, regulatory-flexible, fit for purpose high-performance liquid chromatography (HPLC) analytical method to determine VPM and its impurities. A Placket-Burman screening design was adopted to identify the most relevant analytical conditions affecting the chromatographic responses. In addition, a central composite optimization design was used to establish regression models explaining the chromatographic responses as functions of the buffer pH, concentration of ammonium hydroxide in mobile phase, and the injection volume of test solutions. Response surface methodology allowed for establishing the method operable design space, which ensures suitable method performance with respect to all chromatographic responses studied. Optimal chromatographic conditions were achieved using a gradient elution consisting of a mixture of 10 mM ammonium formate buffer pH and acetonitrile, with a flow rate of 0.7 mL/min, and a XSelect CSH C18 100 mm x 4.6 mm 3.5 µm chromatographic column. The optimized analytical method was selective, linear (320–480 µg/mL for VPM and 0.4–4.8 µg/mL for impurities), precise (0.5% and 1.0% for VPM and impurities, respectively), accurate (mean recovery of 101.0% and 102.5% for VPM and impurities, respectively), and robust. In addition, the application of the validated analytical method in forced degradation conditions allowed for studying the degradation profile of verapamil hydrochloride, particularly in acid and oxidative degradation conditions.

Валідація методики кількісного визначення кардіазолу методом високоефективної рідинної хроматоґрафії

Aim. Validation of the method of quantitative determination of Cardiazole substance by high-performing liquid chromatography technique. Materials and Methods. The object of the study was the [3-allyl-4-(41-methoxyphenyl)-3H-thiazol-2-ylidene]-(32-trifluoromethylphenyl)-amine hydrobromide (Cardiazole) which possesses cardioprotective, anti-inflammatory, analgesic, hypolipidemic, antihypoxic, and antioxidant properties. The compound is patented and involved in the development plan of "Farmak" pharmaceutical company for further preclinical studies workflow. High-performance liquid chromatography was used for the quantitative determination of the Cardiazole substance. Validation of the proposed methodology was performed in accordance with the requirements of the State and European Pharmacopoeias requirements. The obtained data were analyzed using Analyst 1.5.2., as well as Statistica 10.0 and Microsoft Excel software. Results and Discussions. The high-performance liquid chromatography analytical method for the quantitative determination of Cardiazole substance was validated based on the main parameters according to the pharmacopeia requirements. The specificity of the technique was confirmed by comparing the chromatograms of the comparison solution, the test solution, and the blank solution. The linearity parameters are set over the entire range of the analyzed Cardiazole concentrations. The parameters of the correctness of the 9 prepared test solutions within the range of the analytical method application have met the following criteria: requirements for statistical and practical insignificance. The study of the parameters of intra-laboratory precision of 3 tests of the same sample was carried out by two analysts on different days during one week using different measuring ware. Thus, compliance with the criteria was confirmed. The obtained results of the experimental determining of the validation characteristics confirmed the correctness of the technique while reproduced in other laboratories. The results of the stability study showed: for optimal chromatography conditions it is necessary to use a freshly prepared solution of Cardiazole (within 24 hours). Conclusions. The evaluation of the validation parameters of the method of quantitative determination of Cardiazole by high-performance liquid chromatography was carried out. It was shown that the presented method of analysis of Cardiazole meets the requirements for specificity, linearity, accuracy, precision, and stability. The validated analytical method for the quantitative determination of Cardiazole by high-performance liquid chromatography can be used for standardization of the Cardiazole substance, as well as for studying the pharmacokinetics and pharmacodynamics, bioequivalence, and pharmaceutical development of dosage forms. Keywords: validation parameters, Cardiazole, high-performance liquid chromatography

An HPLC Method for detection of Anti-inflammatory Drugs in Bone and Cartilage health supplements

Many bone-building and cartilage repair supplements are available in the market and, many people especially the elderly people use these supplements. Manufacturers claim various therapeutic properties for these types of supplements. Therefore, it is likely that these products are included with chemical and anti-inflammatory drugs that are not listed in labels and brochures. There is not reported using HPLC method to check for chemical and anti-inflammatory drugs in bone and cartilage supplements, by the competent authorities. In this research, a valid, simple, affordable and selective method launched to quantify and identify some corticosteroids in bone and cartilage supplements. This method involves the extraction of the case from supplements using ethanol and injection directly to high-performance liquid chromatography (HPLC). The effect of different variables such as mobile phase, column type, pH and other variables was investigated. Optimum conditions including water-acetonitrile mobile phase with a ratio of 55: 45, ODS column, column temperature of 25°C, injection volume of 20 microliters, detector wavelength of 254 nm and the mobile phase flow rate 1ml/min were obtained. With this HPLC analysis method, cartilage repair products and bone-building supplements can be simply analyzed and the proportion of infected or free corticosteroids can also be identified.

ANTIPROMASTIGOTE AND CYTOTOXIC ACTIVITIES OF FLAVONOIDS FROM Fridericia speciosa LEAVES

Fridericia speciosa (Bignoniaceae) is a liana that occurs in humid to dry vegetation in eastern and southeastern Brazil. Species belonging to the genus Fridericia are employed as medicinal plants. This study evaluates the antipromastigote and cytotoxic activities of the crude extract, fractions, and compounds isolated from F. speciosa, and an HPLC (High-Performance Liquid Chromatography) analytical method was used to quantify the bioactive flavonoids. The flavonoids alpinetin (1), luteolin (2), diosmetin (3), and apigenin (4) were isolated from the active EtOAc-soluble fraction (EAF) of the crude ethanol extract (LCE) obtained from F. speciosa leaves. Both LCE and EAF were active against the normal human lung fibroblast cell line GM07492A (IC50 of 460.7 µg mL-1 and 381.4 µg mL-1, respectively). Only EAF showed activity against Leishmania amazonensis (80.4% at 50 µg mL-1). Compounds 1 and 2 were quantified by HPLC-DAD in both LCE (1: 6.21%; 2: 1.11%) and EAF (1: 45.32%; 2: 2.00%). At 100 µM, compounds1-4 inhibited L. amazonensis flagellar motility by 40.2%, 26.8%, 1.0%, and 24.8%, respectively, while their toxicities (IC50) to the normal cell were > 1000, 353.0, 766.2, and >1000 µg mL-1, respectively. Therefore, F. speciosa leaves are a prolific source of bioactive flavonoids.

Emtricitabine, Tenofovir, and Rilpivirine from their degradation products Analysis by HPLC

A simple, expeditious, and explicit stability-indicating High-Performance Liquid Chromatography (HPLC) analytical test method was developed for the quantitative analysis of Emtricitabine, Tenofovir, and Rilpivirine in bulk drugs and combined dosage formulations. Using the ICH guidelines method was validated using a C18 column of size 250 mm X 4.6 mm, 5µ, maintained at 25oC. The total run time maintained was 10 min. Acetonitrile and 0.1% TEA prepared in water adjusted with pH 3.0 was adapted as a mobile phase. The injection volume of samples was 20μL and UV-DAD detector system set at 265 nm used for UV detection. As per the ICH guidelines method was validated. The retention times were observed as 2.52, 3.27, 6.70 min for Emtricitabine, Rilpivirine, and Tenofovir disoproxyl fumarate, respectively. Linearity ranges were observed 24-56 µg/mL Emtricitabine, 3-7 µg/mL Rilpivirine and 30-70 µg/mL Tenofovir. Relative Standard Deviation not exceed 2%. In contract to the conventional method of HPLC, a method developed was able to give better resolution of swift retention times in the separation of various degradation products along with the pure active pharmaceutical ingredients. The proposed method exhibited excellent reproducibility and repeatability. The stress studies performed by following ICH guidelines indicated that the present HPLC method is explicit and stability-indicating. Since the present HPLC method has the capacity to separate the drugs with high resolution in tablet dosage forms, hence the method can be exploited for routine analysis of quality control sample and stability analysis.

Characterization and topical delivery of phenylethyl resorcinol.

Phenylethyl resorcinol (PR) has been used widely in the personal care industry as a novel skin lightening ingredient. Surprisingly, there is only limited information describing the physicochemical properties of this active. Therefore, the primary objective of this study was to perform a comprehensive characterization of PR. A secondary objective was to investigate the delivery of this molecule to mammalian skin. Phenylethyl resorcinol was characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and nuclear magnetic resonance (NMR). A new high-performance liquid chromatographic (HPLC) method for analysis of PR was developed and validated. The log P (octanol water partition coefficient), value, solubility and short-term stability of PR in a series of vehicles were also determined using HPLC. The evaporation of the selected vehicles was examined using dynamic vapour sorption (DVS). The permeation profiles of PR were investigated under finite dose conditions in porcine and human skin. The melting point of PR was determined to be 79.13°C and the measured log P (octanol water partition coefficient) at 21°C was 3.35±0.03. The linearity of the HPLC analytical method was confirmed with an r2 value of 0.99. Accuracy of the method was evaluated by average recovery rates at three tested concentrations, and the values ranged from 99 to 106%. The limit of detection (LOD) and limit of quantification (LOQ) were 0.19 and 0.57μgmL-1 , respectively. The solubility of PR in PG, DMI, glycerol was within the range of 367 to 877mgmL-1 . The stability of PR in tested solvents was also confirmed by the 72h stability studies. From the DVS studies, 70-125% of applied formulations were recovered at 24h. The permeation through porcine skin at 24h ranged from 4 to 13μgcm-2 , while the corresponding amounts of PR delivered through human skin were 2 to 10μgcm-2 . The physicochemical properties of PR confirm it is suitable for dermal delivery. In this study, propylene glycol was the most promising vehicle for PR delivery to human skin. Future work will expand the range of vehicles studied and explore the percutaneous absorption from more complex formulations.

Validation of an analytical method to quantify the permeation and penetration of flurbiprofen into human pharynx tissue.

The aim of this investigation was to develop receiver and extraction fluids, and subsequently validate an analytical method to quantify the permeation and penetration of flurbiprofen into human pharynx tissue using a Franz diffusion cell. The solubility and stability of flurbiprofen in a suitable receiver fluid, and a suitable extraction method and fluid to recover and quantitate flurbiprofen from human pharynx tissue, were investigated using high‐performance liquid chromatography (HPLC). The potential interference of human pharynx tissue in the receiver fluid was also investigated. The HPLC analytical method was successfully validated according to current guidelines. The final receiver fluid demonstrated sufficient solubility and stability, and the extraction method and fluid resulted in >95% recovery of flurbiprofen following exposure to human pharynx tissue. The lower limit of quantitation of flurbiprofen was 0.045 μg/mL in both the receiver and extraction fluids. There was no interference of the human pharynx tissue with the HPLC method. This investigation validated an analytical method for quantitating flurbiprofen, and determined a suitable receiver fluid and extraction method and fluid, which can be used to investigate the permeation and penetration of flurbiprofen through human pharynx tissue using the Franz diffusion cell method.