Experimental designs and their recent advances in set-up, data interpretation, and analytical applications

Response surface methodology optimizes selenium inhibition of prostate cancer PC-3 cell viability

BACKGROUND

The rising incidence of prostate cancer in the U.S. necessitates innovative therapeutic approaches to this disease. Though extensive research has studied Selenium as an anticarcinogen against prostate cancer, results have varied due to overlooked experimental confounds. Recent studies have identified differential effects of various selenium compounds on prostate cancer cells. This study leverages Mixture Design Response Surface Methodology to characterize the ideal combination of select Se forms against the PC-3 prostate cancer cell line.

METHODS

The PC-3 cell line was chosen as a model for its representation of advanced-stage malignancy. Three Se compounds-sodium selenite, methylseleninic acid, and nano-selenium-were selected for their promising antineoplastic potential. Nano-Se particles were synthesized and subsequently characterized by transmission electron microscopy. Cells were cultured, treated with Se compounds, and assessed for viability using an Alamar Blue Assay. IC50 values of individual Se compounds were determined, and treatment combinations evaluated. In collaboration with statical modeling experts, MDRSM was utilized to optimize Se compound combinations.

RESULTS

Absolute IC50 values were identified for methylseleninic acid (5.01 μmol/L), sodium selenite (13.8 μmol/L), and nano-selenium (14.6 μmol/L). Combining methylseleninic acid and sodium selenite resulted in only 5% PC-3 cell viability, whereas individual treatments reduced viability by approximately 45%. Among the tested mixtures, the 50:50 combination of MSA and sodium selenite most effectively decreased PC-3 cell viability. Regression analysis indicated the special cubic model had a strong fit (multiple r² = 0.9853), predicting maximum cell viability reduction from the methylseleninic acid and selenite mixture.

CONCLUSION

The specific form of Selenium plays a pivotal role in determining its physiological effects and therapeutic potential against prostate cancer. All three selenium compounds showed variable antineoplastic effects, with a 50:50 mixture of methylseleninic acid and selenite exhibiting optimal results. Nano-selenium, when combined with selenite, showed no additive effect, implying a shared mechanism of action. Our research underscores the critical need to consider Se compound forms as distinct entities in prostate cancer treatment and encourages further exploration of Se compounds against prostate cancer.

Carbon black preparation by partial oxidation of spent tyre pyrolysis oil - Influence of temperature, residence time and oxygen to feed ratio

Preparation of carbon black (CB) by partial oxidation of the spent tyre pyrolysis oil (STPO) and its heavy residue fraction (HRF) was systematically studied using a lab-scale drop tube furnace. The effect of furnace operating temperature (T: 1100 to 1400 °C), residence time (tr: 5 to 60 s) and oxygen to feed ratio (O/F: 174 to 732) on the yield and quality of CB was examined using the response surface methodology (RSM). T was shown to have the most significant influence on CB yield and properties. While the CB yield was also influenced by tr, the quality was more sensitively dependent on T and O/F. The predicted optimal tr and O/F were approximately the same for both feedstocks (60 s and 174, respectively). However, T was higher for the HRF feedstock (1368 °C) than the STPO feedstock (1331 °C) due to the abundance of more viscous heavy hydrocarbons in HRF. Validation experiments under the aforementioned conditions demonstrated the models' ability to predict responses accurately. The CB from both feedstocks had low contents of ash (<0.03%), volatiles (∼0.5%), sulphur (<0.7%), and high carbon (≥95%). The BET surface area and average primary particle size for CB from STPO and HRF were comparable to those of commercial CBs from fossil fuel feedstock. The CB from HRF had a higher carboxyl oxygen functional group (18%) compared to the CB from STPO (∼13%) and commercial CB (<5%).

Chiral separation of propranolol by electrokinetic chromatography using nanodiamonds and human serum albumin as a pseudo-stationary phase in river water

Propranolol is currently considered as an emerging contaminant in water bodies. In this study, R- and S-propranolol were determined in river samples by electrokinetic chromatography (EKC) using nanodiamonds (NDs) and human serum albumin (HSA) as a pseudo-stationary phase in order to achieve enantioseparation. Previously, river samples were preconcentrated using a column filled with Amberlite® IR-120 and Dowex® 50WX8 resins. The setting up of influential factors such as temperature, voltage, pH, and HSA and NDs concentration is accurately described along this manuscript. A multivariate study and optimization was carried out to obtain the enantioseparation of propranolol (Rs = 2.91), which was reached under the following experimental conditions: voltage of 16 kV, temperature of 16°C, phosphate buffer pH 9.5, NDs of 0.20%, and HSA of 15 μmol l-1 . The recoveries of analytes under optimal conditions were higher than 98%. The limits of detection were 0.85 μg l-1 for R- and S-propranolol. The method was applied to real samples, and the obtained results in three different water sources studied were 1.02, 0.59, and 0.30 μg l-1 for the R-enantiomer and 0.99, 0.54, and 0.28 μg l-1 for the S-enantiomer. The accuracy of the proposed methodology (including bias and precision) has allowed us to propose it as a successful tool for the control of water quality.

Question-based review for pharmaceutical development: An enhanced quality approach

Over the last years, the pharmaceutical industry has faced real challenges regarding quality assurance. In this context, the establishment of more holistic approaches to the pharmaceutical development has been encouraged. The emergence of the Quality by Design (QbD) paradigm as systematic, scientific and risk-based methodology introduced a new concept of pharmaceutical quality. In essence, QbD can be interpreted as a strategy to maximize time and cost savings. An in-depth understanding of the formulation and manufacturing process is demanded to optimize the safety, efficacy and quality of a drug product at all stages of development. This innovative approach streamlines the pharmaceutical Research and Development (R&D) process, provides greater manufacturing flexibility and reduces regulatory burden. To assist in QbD implementation, International Conference on Harmonisation (ICH), U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) organized and launched QbD principles in their guidance for industry, identifying key concepts and tools to design and develop a high-quality drug product. Despite the undeniable advantages of the QbD approach, and the widespread information on QbD regulatory expectations, its full implementation in the pharmaceutical field is still limited. The present review aims to establish a crosswise overview on the current application status of QbD within the framework of the ICH guidelines (ICH Q8(R2) - Q14 and ICH Q2(R2)). Moreover, it outlines the way information gathered from the QbD methodology is being harmonized in Marketing Authorization Applications (MAAs) for European market approval. This work also highlights the challenges that hinder the deployment of the QbD strategy as a standard practice.

DoE-Assisted Development of a 2H-MoS2 -Catalyzed Approach for the Production of Indole Derivatives

2H-MoS2 is an appealing semiconductor because of its Earth-abundant nature, cheapness, and low toxicity. This material has shown promising catalytic activity for various energy-related processes, but its use in catalysis for C-C bond forming reactions towards useful organic compounds is still largely unexplored. The lack of examples in organic synthesis is mainly due to the intrinsic difficulties of using bulk 2H-MoS2 (e. g., low surface area), which implies the reliance on high catalytic loadings for obtaining acceptable yields. This makes the optimization process more expensive and tedious. Here, we report the development of a 2H-MoS2 -mediated synthesis of valuable bis(indolyl)methane derivatives, using indoles and benzaldehydes as starting materials. Exploiting the Design of Experiments (DoE) method, we identified the critical parameters affecting the catalytic performance of commercial 2H-MoS2 powder and optimized the reaction conditions. Lastly, we demonstrated that the catalytic system has versatility and good tolerance towards functional group variations of the reagents.

A quality by design framework for developing nanocrystal bioenabling formulations

The present study aims to outline a rational framework for the design and development of a 1.0% (w/v) hydrocortisone nanocrystal-based formulation, resorting to a simple, efficient, and scalable nanonization methodology, based on the high-pressure homogenization (HPH) technique. Accordingly, the innovative product was comprehensively optimized following a Quality by Design (QbD) approach. The thorough selection of formulation composition was driven by a dual purpose: improving skin permeation and stability. In the early stage of development, a Failure Mode, Effects and Criticality Analysis (FMECA) diagram was employed to identify the most impactful variables for the critical quality attributes (CQAs). In this sense, a rotatable, three-factor and five-level circumscribed central composite design (CCCD) was applied to investigate how squalene concentration (x1), soluplus concentration (x2) and HPH-time (x3) influence physicochemical properties, performance and physical stability of the formulation. A robust Design Space (DS) was defined, establishing the optimal settings for the critical variables, whose combination meets the requirements set in the quality target product profile (QTPP). Morphological analysis revealed the cuboidal shape of hydrocortisone nanocrystals. In what concerns colloidal properties, the most promising formulation disclosed a small particle size (Dx(50) = 311.8 ± 1.5 nm), along with narrow size distribution (span value = 1.91 ± 0.17). Zeta potential results (-2.19 ± 0.15 mV--12.1 ± 0.4 mV) suggested a steric hindrance stabilization. FTIR spectra showed no chemical interactions between drug and formulation components. XRD diffractograms confirmed loss of crystallinity during the downsizing process. In vitro studies revealed an improvement on drug release rate (316 ± 21-516 ± 35 μg/cm2/√t), compared to the coarse suspension and commercial products, and a straight dependence on the stabilizer concentration and HPH time. The permeation flux across the skin (0.16 ± 0.02-1.2 ± 0.5 μg/cm2/h) appeared to be dependent on the drug physicochemical properties, in particular saturation solubility. Further characterization of the experimental formulations pointed out the role of the stabilizing component to prevent against physical instability phenomena. This organic solvent-free, and therefore "green" nanocrystal production technology offers great potential for pharmaceutical R&D and drug delivery by enabling the development of new forms of conventional drugs with optimal physicochemical properties and performance.

Plackett-Burman and face-centered composite designs for development and optimization of chromatographic method for the simultaneous determination of glycopyrronium, indacaterol and mometasone in their fixed dose combination inhaler - Green profile assessment

A novel simple, specific, sensitive, accurate and precise reversed phase high performance liquid chromatographic method (RP-HPLC/UV) was developed and validated for the simultaneous estimation of Glycopyrronium bromide (GLY), Indacaterol acetate (IND) and Mometasone furoate (MOF) in pure form, in laboratory prepared mixtures and in pharmaceutical dosage form. Experimental design methodology was applied by using Plackett-Burman and face-centered composite designs to achieve the best resolution with minimum experimental trials. The designed model was statistically analyzed, graphically presented by surface plots and the relationships between coefficients of the derived polynomial equations were interpreted. Chromatographic separation was achieved on Inertsil ODS C18 column (250 ×4.6 mm, 5 µm) at ambient temperature using a mobile phase composed of methanol: 0.1% glacial acetic acid (pH4) in a gradient elution at a flow rate 1 mL /min. UV detection was carried out at 233 nm. Response was found to be linear in the concentration range of 20-120 µg /mL with regression coefficient (r2 = 0.999) for GLY, 50-300 µg /mL with regression coefficient (r2 = 0.9995) for IND and 50-300 µg /mL with regression coefficient (r2 = 0.9998) for MOF. The method was validated as per ICH guidelines and satisfactory results were achieved. The method was successfully applied for the analysis of the cited drugs in their fixed dose combination (FDC) pharmaceutical formulation. Statistical comparison between the results obtained by the proposed method and the reference methods for GLY, IND and MOF showed no significant difference. The developed method could be implemented in quality control aspects of the cited drugs. Four green metrics were used to evaluate the new RP-HPLC/UV method's greenness and compare it to other published techniques.

Hydro-organic mobile phase and factorial design application to attain green HPLC method for simultaneous assay of paracetamol and dantrolene sodium in combined capsules

The greenness of any analytical method has become a very important aspect of a good analytical method. However, most chromatographic methods depend on the usage of relatively large amounts of lethal and un-decaying chemicals and solvents. So, a green approach based on the full factorial design was employed to develop a simple and rapid HPLC technique for concurrent determination of paracetamol and dantrolene sodium in their combined capsules. Both drugs are highly recommended to be administered together in patients with severe musculoskeletal disorders. Avoiding the routine methodology and resorting to the modern technology represented in the usage of experimental design allows rapid determination of the studied drugs using the optimum quantity of chemicals to avoid any waste of resources. Simultaneous separation of a binary mixture of paracetamol and dantrolene sodium was accomplished using a reversed phase Hypersil C18 column using an eco-friendly isocratic eluent. The used mobile phase consisted simply of ethanol: water (40:60, v/v). Orthophosphoric acid was used to adjust the pH of the mobile phase to 4.5. Triethanolamine (0.2%) was added aiming to reduce the peak tailing. The assay was completed within less than 6 min adopting 0.8 mL/min as a flow rate. The detection was carried out using a UV-detector at 290 nm. The suggested technique shows a linear correlation over concentration ranges of 1.0-200 and 1.0-40 µg/mL for paracetamol and dantrolene sodium, respectively. The suggested technique allowed the simultaneous analysis of the two co-formulated drugs in their synthetic mixture and combined capsule. The suggested technique is considered a greener substitute for the other reported HPLC techniques through the usage of safer solvents and chemicals, along with decreasing both waste output and analysis time. The method is accurate with recoveries between 97.85 and 101.27%, precise, as %RSD for the intraday and interday precision were between 0.39 and 1.72% and very sensitive with limits of detection (LOD)'s 0.15 and 0.18 µg/ml and limits of quantification (LOQ)'s 0.48 and 0.61 µg/ml for paracetamol and dantrolene sodium, respectively. The method greenness was ensured through its assessment by four greenness metrics. It is also validated following the International Conference on Harmonization Guidelines. The recommended technique could be a good alternative to traditional methods in the routine quality control analysis of the studied drugs due to its minimum harm to the planet or human beings.

Scenedesmus rubescens Heterotrophic Production Strategies for Added Value Biomass

Microalgae attract interest worldwide due to their potential for several applications. Scenedesmus is one of the first in vitro cultured algae due to their rapid growth and handling easiness. Within this genus, cells exhibit a highly resistant wall and propagate both auto- and heterotrophically. The main goal of the present work is to find scalable ways to produce a highly concentrated biomass of Scenedesmus rubescens in heterotrophic conditions. Scenedesmus rubescens growth was improved at the lab-scale by 3.2-fold (from 4.1 to 13 g/L of dry weight) through medium optimization by response surface methodology. Afterwards, scale-up was evaluated in 7 L stirred-tank reactor under fed-batch operation. Then, the optimized medium resulted in an overall productivity of 8.63 g/L/day and a maximum biomass concentration of 69.5 g/L. S. rubescens protein content achieved approximately 31% of dry weight, similar to the protein content of Chlorella vulgaris in heterotrophy.

Analytical quality-by-design approach for development and validation of HPLC method for the simultaneous estimation of omarigliptin, metformin, and ezetimibe: application to human plasma and dosage forms

A simple, selective, and sensitive RP-HPLC method was proposed for the simultaneous determination of two co-administered antidiabetic drugs (omarigliptin and metformin) with an anti-hyperlipidemic drug (ezetimibe) in a medicinally-recommended ratio of 2.5:50:1, respectively. The proposed procedure was optimized by adopting a quality-by-design approach. The influence of different factors on chromatographic responses was optimized by applying the two-level full factorial design (2⁵). The optimum chromatographic separation was achieved using Hypersil BDS C18 column at 45 °C, and the mobile phase pumped isocratically composed of methanol: potassium dihydrogen phosphate buffer (6.6 mM; pH 7, 67:33% v/v) at a flow rate of 0.814 mL/min using 235 nm as a detection wavelength. The developed method was capable of separating this novel mixture in less than 8 min. The calibration plots of omarigliptin, metformin, and ezetimibe showed acceptable linearity over the ranges of 0.2-2.0, 0.5-25.0, and 0.1-2.0 µg/mL with quantitation limits of 0.06, 0.50, and 0.06 µg/mL, respectively. The proposed method was successfully applied to determine the studied drugs in their commercial tablets with high % recoveries (96.8-102.92%) and low % RSD values (less than 2%). The applicability of the method was extended to the in-vitro assay of the drugs in spiked human plasma samples with high % recoveries (94.3-105.7%). The suggested method was validated in accordance with ICH guidelines.

Development of UPLC method for simultaneous assay of some COVID-19 drugs utilizing novel instrumental standard addition and factorial design

A green, rapid, and simple RP-UPLC method was developed and optimized by full factorial design for the simultaneous separation of oseltamivir phosphate, daclatasivir dihydrochloride, and remdesivir, with dexamethasone as a co-administered drug. The separation was established on a UPLC column BEH C₁₈ 1.7 µm (2.1 × 100.0 mm) connected with a UPLC pre-column BEH 1.7 µm (2.1 × 5.0 mm) at 25 °C with an injection volume of 10 µL. The detector (PDA) was set at 239 nm. The mobile phase consisted of methanol and ammonium acetate (8.1818 mM) in a ratio of 75.7: 24.3 (v/v). The flow rate was set at 0.048 mL min^-1. The overall separation time was 9.5 min. The retention times of oseltamivir phosphate, dexamethasone, daclatasivir dihydrochloride, and remdesivir were 6.323 ± 0.145, 7.166 ± 0.036, 8.078 ± 0.124, and 8.572 ± 0.166 min (eight replicates), respectively. The proposed method demonstrated linearity in the ranges of 10.0-500.0 (ng mL^-1) and 0.5-30.0 (µg mL^-1) for oseltamivir phosphate, 50.0-5000.0 (ng mL^-1) for dexamethasone, 25.0-1000.0 (ng mL^-1) and 0.5-25.0 (µg mL^-1) for daclatasvir dihydrochlorde, and 10.0-500.0 (ng mL^-1) and 0.5-30.0 (µg mL^-1) for remdesivir. The coefficients of determination (R²) were greater than 0.9999, with percentage recoveries greater than 99.5% for each drug. The limits of quantitation were 6.4, 1.8, 7.8, and 1.6 ng mL^-1, and the limits of detection were 1.9, 0.5, 2.0, and 0.5 ng mL^-1 for oseltamivir phosphate, dexamethasone, daclatasivir dihydrochloride, and remdesivir, respectively. The proposed method was highly precise, as indicated by the low percentage of relative standard deviation values of less than 1.2% for each drug. The average content and uniformity of dosage units in the studied drugs' dosage forms were determined. The average contents of oseltamivir phosphate, dexamethasone, daclatasivir dihydrochloride, and remdesivir were nearly 93%, 102%, 99%, and 95%, respectively, while the uniformity of dosage unit values were nearly 92%, 102%, 101%, and 97%. Two novel methods were established in this work. The first method was used to assess the stability of standard solutions. This novel method was based on the slope of regression equations. The second was to evaluate the excipient's interference using an innovative instrumental standard addition method. The novel instrumental standard addition method was performed using the UPLC instrument program. It was more accurate, sensitive, time-saving, economical, and eco-friendly than the classic standard addition method. The results showed that the proposed method can estimate the tested drugs' concentrations without interference from their dosage form excipients. According to the Eco-score (more than 75), the Green Analytical Procedure Index (GAPI), and the AGREE criteria (total score of 0.77), the suggested method was considered eco-friendly.

Poly-(MMA-IL) filter paper: A new class of paper-based analytical device for thin-film microextraction of multi-class antibiotics in environmental water samples using LC-MS/MS analysis

A paper-based polymeric ionic liquid (p-Poly-(MMA-IL)) was successfully developed by grafting the polymeric ionic liquid on the surface of commercial filter paper (FP) by using the dipping method, presenting a new cost-effective film. The newly developed p-Poly-(MMA-IL) FP was then applied as a paper-based thin-film microextraction (p-TFME) analytical device to extract 14 compounds as representative of five groups of antibiotic drugs, which were sulfonamides, tetracyclines, fluoroquinolones, penicillin and macrolides in environmental water samples. Besides, p-Poly-(MMA-IL) FP, p-Poly-(MMA) FP, and unmodified filter paper were successfully characterised by FTIR, NMR, FESEM, TGA, and XRD techniques. They underwent significant parameters optimisation, which affected the extraction efficiency. Under optimal conditions, the proposed (p-Poly-(MMA-IL) FP-TFME) device method was evaluated and applied to analyse multi-class antibiotic drugs in environmental water samples by using a liquid chromatography-mass spectrometry (LC-MS). The validation method showed that a good linearity (0.1 μg L^-1 - 500 μg L^-1) was noted (R² > 0.993, n = 3). Detection and quantification limits were within 0.05 μg L^-1 - 4.52 μg L^-1 and 0.15 μg L^-1 - 13.6 μg L^-1, respectively. The relative standard deviation (RSD) values ranged at 1.4%-12.2% (intra-day, n = 15) and 4.4%-11.0% (inter-day, n = 10). The extraction recoveries of environmental water samples ranged from 79.1% to 126.8%, with an RSD of less than 15.4% (n = 3). The newly developed paper-based polymeric ionic liquid (p-Poly-(MMA-IL) FP) for analysis of multi-class antibiotic drugs under the p-TFME analytical device procedure was successfully achieved with limited sample volume and organic solvent, fast extraction, and feasible in daily analysis. The detection concentration and relative RSD of multi-class antibiotics determined in various environmental water samples by the proposed method (n = 5) were within 0.44 μg L^-1 - 54.41 μg L^-1 and 0.69%-15.56%, respectively. These results signified the potential of the p-Poly-(MMA-IL) FP-TFME device as an efficient, sensitive and environmentally friendly approach for analysing antibiotics.

Hydrophilic interaction liquid chromatography-electrospray ionization mass spectrometry combined with fabric phase sorptive extraction for therapeutic drug monitoring of pioglitazone, repaglinide, and nateglinide in human plasma

Polypharmacy in type 2 diabetes is an issue of major concern as the prescription of multiple medi-cations for the management of diabetes-associated comorbidities can lead to drug-to-drug interactions, which can pose serious risks to patients' health. Within this context, the development of bioanalytical methods for monitoring the therapeutic levels of antidiabetic drugs is notably useful to ensure patients' safety. In the present work, a liquid chromatography-mass spectrometry method for the quantitation of pioglitazone, repaglinide, and nateglinide in human plasma is described. Sample preparation was performed by fabric phase sorptive extraction (FPSE), and hydrophilic interaction liquid chromatography (HILIC) was implemented for the chromatographic separation of the analytes, using a ZIC®-cHILIC analytical column (150 × 2.1 mm, 3 µm) under isocratic elution. The mobile phase consisted of 10 mM ammonium formate aqueous solution (pH = 6.5)/ acetonitrile, 10/90 v/v, and was pumped at a flow rate of 0.2 mL min^-1. Design of Experiments was used during the development of the sample preparation method to gain deeper insight into the effect of various experimental parameters on extraction efficiency, their potential interactions and to optimize the recovery rates of the analytes. The linearity of the assay was assessed over the ranges of 25 to 2000, 6.25 to 500, and 125 to 10000 ng mL^-1 for pioglitazone, repaglinide, and nateglinide, respectively. The presented method was fully validated and can be used for the therapeutic monitoring of the targeted analytes in human plasma samples.

A quality-by-design eco-friendly UV-HPLC method for the determination of four drugs used to treat symptoms of common cold and COVID-19

An optimization approach based on full factorial design was employed for developing an HPLC-UV method for simultaneous determination of a quaternary mixture used for the treatment of symptoms related to common cold and COVID-19. The quaternary mixture is composed of paracetamol, levocetirizine dihydrochloride, phenylephrine hydrochloride and ambroxol hydrochloride. The developed technique is a green, fast and simple method that uses isocratic elution of mobile phase consisting of 20:5:75 (v/v) of ethanol: acetonitrile: 2.5 mM heptane-1-sulphonic acid sodium salt at pH 6.5 [Formula: see text] 0.02. The chromatographic separation was carried out using Hypersil BDS Cyano LC Column (250 × 4.6 mm, 5 μm) with 230 nm UV detection and 1.0 mL/min. flow rate. Avoiding the routine methodology and resorting to the modern technology-represented in the usage of experimental design-allows rapid determination of the four drugs using the optimum quantity of chemicals to avoid any waste of resources. The quaternary mixture was eluted in less than 9 min., where retention times of paracetamol, levocetirizine dihydrochloride, phenylephrine hydrochloride and ambroxol hydrochloride were found to be 2.2, 3.8, 6.6 and 8.8 min., respectively. The calibration graphs of the four drugs were linear over concentration ranges of 50.0-500.0, 0.5-20.0, 0.5-20.0 and 0.5-100.0 µg/mL for paracetamol, levocetirizine dihydrochloride, phenylephrine hydrochloride and ambroxol hydrochloride, respectively with correlation coefficients higher than 0.999. The method is accurate with mean recoveries between 99.87 and 100.04%, precise, as %RSD for the intraday and interday precision were between 0.61 and 1.64% and very sensitive with limit of detections (LOD)'s between 29 and 147 ng/mL and limit of quantification (LOQ)'s between 95 and 485 ng/mL. The proposed method was successfully applied for the analysis of the four drugs either in raw materials or in prepared tablet with the least amount of chemicals within short time. It is also validated following International Conference on Harmonization Guidelines. The proposed method was found to be green according to the most common greenness assessment tools; NEMI, GAPI, Analytical Eco-Scale and AGREE methods. The advantages of the proposed method qualify it for routine analysis of the studied drugs either in single or co-formulated dosage form in quality control labs.

Ultrasound-Assisted Extraction of Polyphenols from Maritime Pine Residues with Deep Eutectic Solvents

Deep eutectic solvents represent an important alternative in the field of green solvents due to their low volatility, non-toxicity, and low synthesis cost. In the present investigation, we propose the production of enriched polyphenolic extracts from maritime pine forest residues via an ultrasound-assisted approach. A Box-Behnken experimental design with a response surface methodology was used with six variables to be optimized: solid-to-solvent ratio, water percentage, temperature and time of extraction, amplitude, and catalyst concentration. The mixture of levulinic and formic acids achieved the highest extraction yield of polyphenols from pine needle and bark biomass. In addition, the solid-to-solvent ratio was found to be the only influential variable in the extraction (p-value: 0.0000). The optimal conditions were established as: 0.1 g of sample in 10 mL of LA:FA (70:30%, v/v) with 0% water and 0 M H₂SO₄ heated to 30 °C and extracted during 40 min with an ultrasound amplitude of 80% at 37 kHz. The bioactive properties of polyphenol-enriched extracts have been proven with significant antioxidant (45.90 ± 2.10 and 66.96 ± 2.75 mg Trolox equivalents/g dw) and antimicrobial activities. The possibility to recycle and reuse the solvent was also demonstrated; levulinic acid was successfully recovered from the extracts and reused in novel extractions on pine residues. This research shows an important alternative to obtaining polyphenol-enriched extracts from forest residues that are commonly discarded without any clear application, thus opening an important window toward the valorization of such residues.

Analytical Quality by Design (AQbD) Approach to the Development of Analytical Procedures for Medicinal Plants

Scientific regulatory systems with suitable analytical methods for monitoring quality, safety, and efficacy are essential in medicinal plant drug discovery. There have been only few attempts to adopt the analytical quality by design (AQbD) strategy in medicinal plants analysis over the last few years. AQbD is a holistic method and development approach that understands analytical procedure, from risk assessment to lifecycle management. The enhanced AQbD approach reduces the time and effort necessary to develop reliable analytical methods, leads to flexible change control through the method operable design region (MODR), and lowers the out-of-specification (OOS) results. However, it is difficult to follow all the AQbD workflow steps in the field of medicinal plants analysis, such as defining the analytical target profiles (ATPs), identifying critical analytical procedure parameters (CAPPs), among others, because the complexity of chemical and biological properties in medicinal plants acts as a barrier. In this review, various applications of AQbD to medicinal plant analytical procedures are discussed. Unlike the analysis of a single compound, medicinal plant analysis is characterized by analyzing multiple components contained in biological materials, so it will be summarized by focusing on the following points: Analytical methods showing correlations within analysis parameters for the specific medicinal plant analysis, plant raw material diversity, one or more analysis targets defined for multiple phytochemicals, key analysis attributes, and analysis control strategies. In addition, the opportunities available through the use of design-based quality management techniques and the challenges that coexist are also discussed.

A chemometric experimental design with three-step stacking capillary electrophoresis for analysis of five tobacco-specific nitrosamines in cigarette products

Tobacco-specific nitrosamines (TSNAs) as carcinogens endanger our health and life from cigarette products. However, the safe range of TSNAs levels in commercial cigarette products has not yet been established. For the purpose of safety and supervision, a three-step stacking approach including field amplified sample injection (FASI), sweeping, and analyte focusing by micelle collapse (AFMC), was developed for the simultaneous determination of five TSNAs levels in cigarette products. This approach also involved aspects of chemometric experimental design, including fractional factorial design and central composite design. After the multilevel optimization of the experimental design, the five TSNAs were well separated. The LOD (S/N = 3) values of the N´-nitrosonornicotine (NNN), N´-nitrosoanatabine (NAT), N´-nitrosoanabasine (NAB), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in the FASI-sweeping-AFMC CE approach were 1.000 ng/mL, 0.500 ng/mL, 0.125 ng/mL, 1.000 ng/mL, and 0.500 ng/mL respectively. The results of relative standard deviation (RSD) and relative error (RE) were all less than 3.35%, demonstrating good precision and accuracy. Finally, this novel approach was further applied to monitor three commercial cigarette products, and a range of 250.1-336.6 ng/g for NNN, 481.6-526.7 ng/g for NAT, 82.2-247.6 ng/g for NAB, 167.7-473.7 ng/g for NNAL, and 39.4-246.7 ng/g for NNK could be observed among these. Based on these results, the novel CE stacking strategy was successfully applied for the analysis of five TSNAs levels in cigarette products and could serve as a tool for assays of quality control of nitrosamines.

A Ribonucleotide ↔ Phosphoramidate Reaction Network Optimized by Computer-Aided Design

A growing number of out-of-equilibrium systems have been created and investigated in chemical laboratories over the past decade. One way to achieve this is to create a reaction cycle, in which the forward reaction is driven by a chemical fuel and the backward reaction follows a different pathway. Such dissipative reaction networks are still relatively rare, however, and most non-enzymatic examples are based on the carbodiimide-driven generation of carboxylic acid anhydrides. In this work, we describe a dissipative reaction network that comprises the chemically fueled formation of phosphoramidates from natural ribonucleotides (e.g., GMP or AMP) and phosphoramidate hydrolysis as a mild backward reaction. Because the individual reactions are subject to a multitude of interconnected parameters, the software-assisted tool “Design of Experiments” (DoE) was a great asset for optimizing and understanding the network. One notable insight was the stark effect of the nucleophilic catalyst 1-ethylimidazole (EtIm) on the hydrolysis rate, which is reminiscent of the action of the histidine group in phosphoramidase enzymes (e.g., HINT1). We were also able to use the reaction cycle to generate transient self-assemblies, which were characterized by dynamic light scattering (DLS), confocal microscopy (CLSM), and cryogenic transmission electron microscopy (cryo-TEM). Because these compartments are based on prebiotically plausible building blocks, our findings may have relevance for origin-of-life scenarios.

Development and Validation of a Novel HPLC Method for the Determination of Ephedrine Hydrochloride in Nasal Ointment

A simple, precise, and cost-effective reverse phase ion pair chromatographic (RP-IP-HPLC) method was developed and validated for the determination of Ephedrine Hydrochloride in a nasal ointment. A simple and fast extraction protocol was developed for the effective recovery of the analyte, and for this purpose, Bromhexine Hydrochloride was used as the internal standard. The mobile phase consisted of MeOH, Sodium Lauryl Sulfate (SLS) 49.8 mM, triethylamine (ET3N) in the ratio of 65:34.6:0.4%, respectively, with pH = 2.20. The detection of the compounds was carried out at 206 nm, and we used a PDA detector. A short run time was achieved with retention times of 6.3 min and 9.8 min for ephedrine hydrochloride and the internal standard, respectively. The proposed method was validated according to ICH guidelines. Linearity was confirmed in the range of 50–150 μg/mL. Recoveries results were within the range of 98–102% and precision < 2% for the analyte in spiked blank matrix. Robustness testing was conducted via a fractional factorial experimental design. The method was found to fulfill the required specifications for specificity and stability for both standard solutions and samples, as well and applied to the determination of ephedrine hydrochloride in nasal ointments produced by the Greek Military Pharmaceutical Laboratories.

Improving the oral delivery of benznidazole nanoparticles by optimizing the formulation parameters through a design of experiment and optimization strategy

Chagas disease is a neglected tropical disease affecting the American continent and also some regions of Europe. Benznidazole, approved by FDA, is a drug of choice but its poor aqueous solubility may lead to a low bioavailability and efficacy. Therefore, the aim of this study was to formulate nanoparticles of benznidazole for improving its solubility, dissolution and permeability. A Plackett-Burman design was applied to identify the effect of 5 factors over 4 responses. Then, a Central Composite design was applied to estimate the values of the most important factors leading to the best compromise between highest nanoprecipitation efficiency, drug solubility and lower particle size. The optimized nanoparticles were evaluated for in vitro drug release in biorelevant media, stability studies and transmission electron microscopy. Biocompatibility and permeability of nanoparticles were evaluated on the Caco-2 cell line. The findings of the optimization process indicated that concentration of drug and stabilizer influenced significantly the particle size while concentration of stabilizer and organic/water phase volume ratio mainly influenced the drug solubility. Stability studies suggested that benznidazole nanoparticles were stable after 12 months at different temperatures. Minimal interactions of those nanoparticles and mucin glycoproteins suggested favorable properties to address the intestinal mucus barrier. Cell viability studies confirmed the safety profile of the optimized formulation and showed an increased permeation through the Caco-2 cells. Thus, this study confirmed the suitability of the design of experiment and optimization approach to elucidate critical parameters influencing the quality of benznidazole nanoparticles, which could lead to a more efficient management of Chagas disease by oral route.

Generic approach in a gradient elution HPLC method development that enables troubleshooting free method transfer

Nowadays, method development is strongly focused on reducing time needed for method development and execution. This subject specially concerns gradient elution methods regarding the usual need for troubleshooting assistance with uncertain outcome during the method transfer from one laboratory to another. One of the main reasons for this situation is the dwell volume difference between HPLC systems. Therefore, the aim of this study was to propose a novel method development methodology that would integrate the dwell volumes differences in the optimization process. The proposed approach could be quite useful in industry that has insight in HPLC instruments planned to be used during the method life cycle. It was tested on the model mixture consisting of dabigatran etexilate mesylate and its nine impurities by use of experimental design methodology. Three different (U)HPLC instruments with high dwell volume differences were selected to challenge the methodology. Plan of experiments was defined with Plackett-Burman design for screening phase and D-optimal design for optimization phase. Initial and final amount of organic modifier, time of the gradient elution and pH value of the aqueous phase were selected as variables significant for the gradient programme profile and included in the optimization stage along with dwell volume values. The separation criteria s between critical peak pairs was selected as output for method optimization while indirect modelling together with Monte Carlo simulations enabled selection of optimal and robust chromatographic conditions. They included 24% (v/v) of initial amount of acetonitrile, 54% (v/v) of the final amount of acetonitrile, 15 min of gradient elution run time and pH value equal to 4.9. The proposed method was successfully validated, met all validation criteria and thus proved its utility.

Silibinin loaded inhalable solid lipid nanoparticles for lung targeting

AIM

In the current study, efforts are being made to prepare Inhalable Silibinin loaded solid lipid nanoparticles (SLNs) with narrow size distribution with improved bioavailability.

METHODS

SLNs were formulated by high shear homogenisation method SLNs were characterised, including Differential Scanning Calorimetry (DSC), Fourier transform infra-red spectroscopy (FTIR), particle size analysis, entrapment efficiency with Aerodynamic behaviour. The MTT assay was performed against A549 cell line, to measure their anticancer cell activity with In vivo study.

RESULTS

Optimized formulation exhibited spherical surface with a mean particle size of 221 ± 1.251 nm, PI of 0.121 ±  0.081, zeta potential of -4.12 ± 0.744. Aerodynamic behaviour such as Mass median aerodynamic diameter (MMAD) and Geometric size distribution (GSD) were found to be 5.487 ± 0.072 and 2.321 ± 0.141 respectively proved formulation is suitable for inhalation. In vitro cellular efficacy against A549 cells, revealed that the optimised formulations were more effective and potent.

CONCLUSION

The Inhalable SLNs approach was successfully engineered and administered to the lungs safely without causing any problems.

Self-supported 3D reduced graphene oxide for solid-phase extraction: An efficient and low-cost sorbent for environmental contaminants in aqueous solution

A 3D reduced graphene oxide (3D-rGO), a self-supported, efficient, and low-cost sorbent, was synthesised and employed in a solid-phase extraction (SPE) cartridge. As a proof of concept, it was applied to remove diclofenac from aqueous solution. After applying statistical methods to systematically investigate key parameters for optimizing the 3D-rGO cartridge performance, it reached removal and elution efficiencies of 100 % and 90 %, respectively. This SPE cartridge presented advantages compared to traditional ones as the smaller amount of material into the cartridge (mass twenty times smaller), in addition to the ability of eliminating sorbent preconditioning, reducing the use of solvents, and making the process environmentally friendly with a faster operation. Also, it presented improved reproducibility after several cycles of reuse, and finally a lower cost of production unveiled by a cost-benefit analysis. Analysis with scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectrometry, Raman, and Fourier transform infrared spectroscopy in attenuated total reflectance mode suggested that the 3D framework morphology with a high content of carbon at the surface and some residual oxygen-containing groups are the protagonists in this performance. Therefore, 3D-rGO has the potential to be a highly efficient sorbent in analytical procedures using SPE for environmental contaminants in water and effluent samples.

Enantiomeric profiling of mefentrifluconazole in watermelon across China: Enantiochemistry, environmental fate, storage stability, and comparative dietary risk assessment

Elucidating the enantiomeric chemistry and enantioselective fate of the novel chiral triazole fungicide mefentrifluconazole is of vital importance for agroecosystem safety and human health. The absolute configuration of mefentrifluconazole was identified firstly as S-(+)-mefentrifluconazole and R-(-)-mefentrifluconazole on a cellulose tris(3-chloro-4-methylphenylcarbamate) chiral phase. A baseline resolution (Rs, 2.51), favorable retention (RT ≤ 2.24 min), and high sensitivity (LOQ, 0.5 μg/kg) of enantiomer pair were achieved by reversed-phase liquid chromatography tandem mass spectrometry combined with a 3D response surface strategy. Nationwide field trials were undertaken to clarify the enantiomer occurrence, enantioselective dissipation, terminal concentrations, and storage stability of S-mefentrifluconazole and R-mefentrifluconazole in watermelon across China. The original deposition of the sum of enantiomer pair was estimated to be 14.4-163.7 μg/kg, and terminally decreased to < LOQ-59.3 μg/kg 10 days after foliage application. S-mefentrifluconazole preferentially degraded (T_1/2, 3.3-6.0 days), resulting in the relative enrichment of R-mefentrifluconazole (T_1/2, 3.9-6.6 days) in watermelon. A probabilistic model is recommended for the dietary risk assessment, although both acute (%ARfD, 0.435-22.188%) and chronic (%ADI, 1.697-9.658%) risks are acceptable for associated population. The long-term exposures should be continuously emphasized given the increasing applications and persistent fate of mefentrifluconazole, especially for urban children.

Application of Experimental Design Methodologies in the Enantioseparation of Pharmaceuticals by Capillary Electrophoresis: A Review

Chirality is one of the major issues in pharmaceutical research and industry. Capillary electrophoresis (CE) is an interesting alternative to the more frequently used chromatographic techniques in the enantioseparation of pharmaceuticals, and is used for the determination of enantiomeric ratio, enantiomeric purity, and in pharmacokinetic studies. Traditionally, optimization of CE methods is performed using a univariate one factor at a time (OFAT) approach; however, this strategy does not allow for the evaluation of interactions between experimental factors, which may result in ineffective method development and optimization. In the last two decades, Design of Experiments (DoE) has been frequently employed to better understand the multidimensional effects and interactions of the input factors on the output responses of analytical CE methods. DoE can be divided into two types: screening and optimization designs. Furthermore, using Quality by Design (QbD) methodology to develop CE-based enantioselective techniques is becoming increasingly popular. The review presents the current use of DoE methodologies in CE-based enantioresolution method development and provides an overview of DoE applications in the optimization and validation of CE enantioselective procedures in the last 25 years. Moreover, a critical perspective on how different DoE strategies can aid in the optimization of enantioseparation procedures is presented.

Lipid Nanoparticles Loaded with Selected Iridoid Glycosides as Effective Components of Hydrogel Formulations

One possibility of improving active ingredient penetration into deeper skin layers to enhance the cosmetic product effectiveness, is the application of lipid nanoparticles. The aim of the study presented in this paper was to evaluate the potential of hydrogel formulations enriched with iridoid glycosides-loaded lipid nanoparticles. Lipid nanocarriers were produced using an emulsification-ultrasonication method based on multiple emulsions. The encapsulation efficiency was determined at the level of 89% and 77% for aucubin and catalpol, respectively. The next stage was the incorporation of the obtained dispersions of lipid nanoparticles into hydrogel formulations, followed by determination of their physicochemical properties, shelf-life stability, and application properties (in vivo tests). The introduction of lipid nanoparticles increased the stabilization of the consistency of the obtained hydrogel formulations, and was confirmed by viscosity measurements. No effect of lipid nanoparticle incorporation on shelf-life stability of the hydrogels was detected. In vivo studies showed improvements in moisture content of the epidermis, transepidermal water loss, skin topography, and macrorelief parameters. In particular, a synergistic effect of the active ingredients and lipid nanoparticles on the anti-wrinkle effect, moisturizing effect, and regeneration of the protective barrier of the stratum corneum was evidenced. The attractiveness of aucubin and catalpol as cosmetic raw materials in hydrogel formulations was evidenced, especially when the iridoid glycosides were applied in the form of lipid nanoparticles.

Experimental Design Based Optimization and Ex Vivo Permeation of Desmopressin Acetate Loaded Elastic Liposomes Using Rat Skin

The study aimed to develop elastic-liposome-based transdermal delivery of desmopressin acetate for enhanced permeation to control enuresis, central diabetes insipidus, and traumatic injury. Elastic liposomes (ELs)-loaded desmopressin acetate was prepared, optimized, and evaluated for improved transdermal permeation profiles using rat skin. Full factorial design with independent factors (X₁ for lipid and X₂ for surfactant) at three levels was used against four responses (Y₁, Y₂, Y₃, and Y₄) (dependent variables). Formulations were characterized for vesicle size, polydispersity index (PDI), zeta potential, % entrapment efficiency (% EE), in vitro drug release, in vitro hemolysis potential, ex vivo drug permeation and drug deposition (DD), and ex vivo vesicle–skin interaction using scanning electron microscopy studies. The optimized formulation ODEL1 based on desirability function was found to have vesicle size, % EE, % DR, and permeation flux values of 118.7 nm, 78.9%, 75.1%, and 5.3 µg/h·cm², respectively, which were close to predicted values. In vitro release profiles indicated slow and sustained delivery. Permeation flux values of ODEL1 and ODEL2 were 5.3 and 3.1 µg/h·cm², respectively, which are 7.5- and 4.4-fold higher as compared to DS (0.71 µg/h·cm²). The obtained flux was relatively higher than the clinical target value of the drug for therapeutic efficacy. Moreover, the DD value of ODEL1 was significantly higher than ODEL2 and DS. Hemocompatibility study confirmed safety concerns. Finally, vesicle–skin interaction corroborated mechanistic views of permeation through rat skin. Conclusively, the transdermal delivery may be a suitable alternative to oral and nasal delivery to treat nocturnal enuresis, central diabetes insipidus, hemophilia A and von Willebrand’s disease, and any traumatic injuries.

A green and sustainable method for monitoring the chemical composition of soybean: an alternative for quality control

INTRODUCTION

Soybean is one of the most important crops in the world, an important source of isoflavones, and used to treat various chronic diseases. High-performance liquid chromatography (HPLC), associated with multivariate experiments and green solvents, is increasingly used to develop comprehensive elution methods for quality control of plants and derivatives.

OBJECTIVE

The work aims to establish a HPLC fingerprinting method for soybean seeds employing Green Chemistry Principles, a sustainable solvent with low toxicity, and a comprehensive experimental design that reduces the number of experiments.

MATERIALS AND METHODS

The fingerprinting method was optimised through Design of Experiments by evaluating seven chromatographic variables: initial percentage of ethanol (X1), final percentage of ethanol (X2), temperature (X3), percentage of acetic acid in water (X4), flow rate (X5), run time (X6), and stationary phase (X7). The dependent variable was the number of peaks (n).

RESULTS

An initial factorial design for screening purposes indicated that the most significant quantitative parameters to separate soybean metabolites were X1 and X3. The conditions were optimised by a Doehlert design, to obtain a HPLC-PAD (photodiode array detector) fingerprinting of the polar extract of soybean seeds with the markers identified by liquid chromatography electrospray ionisation tandem mass spectrometry (LC-ESI-MS/MS). The optimum fingerprinting method was determined as 5-55% of ethanol in 30 min, at 35°C, and flow rate of 1 mL/min, by employing a phenyl-hexyl column (150 mm × 4.6 mm).

CONCLUSION

The developed green method enabled markers of soybean to be separated and identified and could be an eco-friendlier alternative for soybean quality control that covered seven Green Analytical Chemistry Principles.

Development and Validation of an HPLC Method Using an Experimental Design for Analysis of Amlodipine Besylate and Enalapril Maleate in a Fixed-dose Combination

Objectives

The aim of this study was to develop and optimize a simple, cost-effective, and robust high-performance liquid chromatography (HPLC) method by taking an experimental design approach to the assay and dissolution analysis of amlodipine besylate and enalapril maleate from a fixed-dose combination tablet.

Materials and Methods

The chromatographic analysis was performed on a C18 column (4.6x250 mm id., particle size of 5 μm). The injection volume was 5 μL, and the detection wavelength was 215 nm. A Box-Behnken design was used to test the robustness of the method. The flow rate (1, 1.2, and 1.4 mL/min), column temperature (25°C, 30°C, and 35°C), methanol ratio of the mobile phase (5, 10, and 15%), and pH of the mobile phase (2.8, 3, and 3.2) were selected as independent variables. The method was validated according to International Conference on Harmonization guidelines. Dissolution of the tablets was performed by using USP apparatus 2 and analyzed using the optimized HPLC method. Multivariate linear regression analysis and ANOVA were used in the statistical evaluation.

Results

Linear models were fitted for all variables. The flow rate was the most significant factor affecting the APIs' concentrations. The optimized method included the following parameters: Column temperature of 25°C, 10% methanol as the mobile phase, pH of 2.95, and flow rate of 1.205 mL/min. Retention times were 3.8 min and 7.9 min for enalapril and amlodipine, respectively. The method was found to be linear in the range of 0.8-24 μg/mL (R² >0.999) and 1.6-48 μg/mL (R² >0.999) for amlodipine and enalapril, respectively. Both APIs were dissolved more than 85% within 10 min.

Conclusion

The experimental design was proved as a useful tool for the determination and separation of enalapril maleate and amlodipine besylate in dosage forms. The optimized method can be used for in vitro performance and quality control tests of fixed-dose tablet combinations containing enalapril maleate and amlodipine besylate.

Chemo-metric engineering designs for deciphering the biodegradation of polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are non-polar organic compounds that are omnipresent in the environment and released due to anthropogenic activities through emissions and discharges. PAHs, being xenobiotic and exerts health impacts, thus they attract serious concern by the environmentalists. The stringent regulations and the need of sustainable development urges the hunt for a technically feasible and cost-effective wastewater treatment. Although the conventional physico-chemical treatment are widely preferred, they cause secondary pollution problems and demand subsequent treatment options. This comprehensive review intends to address the (a) different PAHs and their associated toxicity, (b) the remedial strategies, particularly biodegradation. The biological wastewater treatment techniques that involve microbial systems are highly influenced by the different physio-chemical and environmental parameters. Therefore, suitable optimization techniques are prerequisite for effective functioning of the biological treatment that sustains judiciously and interpreted in a lesser time. Here we have aimed to discuss (a) different chemo-metric tools involved in the design of experiments (DoE), (b) design equations and models, (c) tools for evaluating the model's adequacy and (d) plots for graphically interpreting the chemo-metric designs. However, to best of our knowledge, this is a first review to discuss the PAHs biodegradation that are tailored by chemo-metric designs. The associated challenges, available opportunities and techno-economic aspects of PAHs degradation using chemo-metric engineering designs are explained. Additionally, the review highlights how well these DoE tools can be suited for the sustainable socio-industrial sectors. Concomitantly, the futuristic scope and prospects to undertake new areas of research exploration were emphasized to unravel the least explored chemo-metric designs.

In Situ Decarboxylation-Pressurized Hot Water Extraction for Selective Extraction of Cannabinoids from Cannabis sativa. Chemometric Approach

Isolation of the therapeutic cannabinoid compounds from Cannabis Sativa L. (C. Sativa) is important for the development of cannabis-based pharmaceuticals for cancer treatment, among other ailments. The main pharmacological cannabinoids are THC and CBD. However, THC also induces undesirable psychoactive effects. The decarboxylation process converts the naturally occurring acidic forms of cannabinoids, such as cannabidiolic acid (CBDA) and tetrahydrocannabinolic acid (THCA), to their more active neutral forms, known as cannabidiol (CBD) and tetrahydrocannabinol (THC). The purpose of this study was to selectively extract cannabinoids using a novel in situ decarboxylation pressurized hot water extraction (PHWE) system. The decarboxylation step was evaluated at different temperature (80–150 °C) and time (5–60 min) settings to obtain the optimal conditions for the decarboxylation-PHWE system using response surface methodology (RSM). The system was optimized to produce cannabis extracts with high CBD content, while suppressing the THC and CBN content. The identification and quantification of cannabinoid compounds were determined using UHPLC-MS/MS with external calibration. As a result, the RSM has shown good predictive capability with a p-value < 0.05, and the chosen parameters revealed to have a significant effect on the CBD, CBN and THC content. The optimal decarboxylation conditions for an extract richer in CBD than THC were set at 149.9 °C and 42 min as decarboxylation temperature and decarboxylation time, respectively. The extraction recoveries ranged between 96.56 and 103.42%, 95.22 and 99.95%, 99.62 and 99.81% for CBD, CBN and THC, respectively.

Lipid Nanoparticles Loaded with Iridoid Glycosides: Development and Optimization Using Experimental Factorial Design

Lipid nanoparticles based on multiple emulsion (W/O/W) systems are suitable for incorporating hydrophilic active substances, including iridoid glycosides. This study involved optimization of composition of lipid nanoparticles, incorporation of active compounds (aucubin and catalpol), evaluation of stability of the resulting nanocarriers, and characterization of their lipid matrix. Based on 32 factorial design, an optimized dispersion of lipid nanoparticles (solid lipid:surfactant-4.5:1.0 wt.%) was developed, predisposed for the incorporation of iridoid glycosides by emulsification-sonication method. The encapsulation efficiency of the active substances was determined at nearly 90% (aucubin) and 77% (catalpol). Regarding the stability study, room temperature was found to be the most suitable for maintaining the expected physicochemical parameter values (particle size < 100 nm; polydispersity index < 0.3; zeta potential > |± 30 mV|). Characterization of the lipid matrix confirmed the nanometer size range of the resulting carriers (below 100 nm), as well as the presence of the lipid in the stable β' form.

Development of a HS-SPME/GC-MS Method for the Extraction and Identification of the Volatile Compounds Emitted by Flowers of Tillandsia xiphioides

Tillandsia is a genus belonging to the Bromeliaceae family, most of which are epiphytes. The flowers of some of the Tillandsia species are very fragrant, but the volatile composition has been scarcely reported. In this report, we studied the chemical composition of volatile compounds emitted by the flowers of Tillandsia xiphioides using the HS-SPME/GC-MS method. The extraction conditions (fiber, temperature, and time) were optimized using a multivariate approach, and the composition of the extracted volatiles was determined by gas chromatography coupled with mass spectrometry (GC-MS). In total, 30 extracted compounds were identified. Two extraction methods are necessary for the efficient extraction of the volatile compounds. These results were applied to profile two forms of T. xiphioides.

Employment of Quality by Design Approach via Response Surface Methodology to Optimize and Develop Modified-release Formulation of Hydrochlorothiazide

BACKGROUND

Heart attack predominantly occurs during the last phase of sleep and early morning hours, causing millions of death worldwide. Hydrochlorothiazide (HCTZ) is a recommended drug for the prevention of heart disease, but its long action (>4 h) dosage form is lacking in the commercial market and development of modified-release formulation may have industrial significance. Regulatory agencies emphasize Quality by Design based approach for product development to entrust quality in the product.

OBJECTIVE

The current research aimed to develop a quality product profile of HCTZ modifiedrelease tablets (MRT; ~14 h) by applying Response Surface Methodology using the computational QbD approach.

METHODS

Three independent factors were identified by qualitative and quantitative risk assessment. Statistical terms like p-value, lack of fit, the sum of square, R-squared value, model F value, and linear equations were determined. Graphical tools like normal plot of residual, residual vs predicted plot and box cox plot were used to verify the model selection. The graphical relationship among the critical, independent variables was represented using the Contour plot and 3-D surface plot. Design space was identified by designing an overlay plot using response surface design.

RESULTS

Excellent correlation was observed between actual and predicted values. Similarity Factor (F2) of reproducible trials was 78 and 79, and content uniformity was 100.9% and 100.4%. Average weight, hardness, thickness, diameter, and friability were within acceptable limits.

CONCLUSION

QbD approach, along with a quality risk management tool, provided an efficient and effective paradigm to build quality MRT of HCTZ.

A Systematic, Knowledge Space-Based Proposal on Quality by Design-Driven Polymeric Micelle Development

Nanoparticle research and development for pharmaceuticals is a challenging task in the era of personalized medicine. Specialized and increased patient expectations and requirements for proper therapy adherence, as well as sustainable environment safety and toxicology topics raise the necessity of well designed, advanced and smart drug delivery systems on the market. These stakeholder expectations and social responsibility of pharma sector open the space and call new methods on the floor for new strategic development tools, like Quality by Design (QbD) thinking. The extended model, namely the R&D QbD proved to be useful in case of complex and/or high risk/expectations containing or aiming developments. This is the case when we formulate polymeric micelles as promising nanotherapeutics; the risk assessment and knowledge-based quality targeted QbD approach provides a promising tool to support the development process. Based on risk assessment, many factors pose great risk in the manufacturing process and affect the quality, efficacy and safety profile. The quality-driven strategic development pathway, based on deep prior knowledge and an involving iterative risk estimation and management phases has proven to be an adequate tool, being able to handle their sensitive stability issues and make them efficient therapeutic aids in case of several diseases.

Design of Experiment on Concrete Mechanical Properties Prediction: A Critical Review

Concrete mix design and the determination of concrete performance are not merely engineering studies, but also mathematical and statistical endeavors. The study of concrete mechanical properties involves a myriad of factors, including, but not limited to, the amount of each constituent material and its proportion, the type and dosage of chemical additives, and the inclusion of different waste materials. The number of factors and combinations make it difficult, or outright impossible, to formulate an expression of concrete performance through sheer experimentation. Hence, design of experiment has become a part of studies, involving concrete with material addition or replacement. This paper reviewed common design of experimental methods, implemented by past studies, which looked into the analysis of concrete performance. Several analysis methods were employed to optimize data collection and data analysis, such as analysis of variance (ANOVA), regression, Taguchi method, Response Surface Methodology, and Artificial Neural Network. It can be concluded that the use of statistical analysis is helpful for concrete material research, and all the reviewed designs of experimental methods are helpful in simplifying the work and saving time, while providing accurate prediction of concrete mechanical performance.

Design of experiments for development and optimization of a liquid chromatography coupled to tandem mass spectrometry bioanalytical assay

Design of experiments (DoE) is a valuable tool for the optimization of quantitative bioanalytical methods utilizing liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Liquid chromatography mass spectrometry (LC-MS) is composed of several processes, including, liquid introduction and analyte ionization. The goal is to transfer analytes from atmospheric pressure to vacuum and maintain conditions that are compatible for both LC and MS. These processes involve many experimental factors which need to be simultaneously optimized to obtain maximum sensitivity and resolution at minimum retention time. In this tutorial, the basic concepts of DoE will be explained with focus on practical use of DoE. Three case studies optimized with DoE for liquid chromatography tandem mass spectrometry (LC-MS/MS) quantitative assays will then be presented.

A novel quality by design approach for development and validation of a green reversed-phase HPLC method with fluorescence detection for the simultaneous determination of lesinurad, febuxostat, and diflunisal: Application to human plasma

A novel and eco-friendly reversed-phase HPLC method with fluorescence detection was developed for simultaneous estimation of two co-administered antigout drugs (lesinurad and febuxostat) with diflunisal as a nonsteroidal anti-inflammatory drug. Unlike routine methodology, the developed method was optimized using analytical quality by design approach. A full factorial design was applied to optimize the effect of variable factors on chromatographic responses. The chromatographic separation was performed using isocratic elution on the Hypersil BDS C18 column at 40°C. The mobile phase consisted of acetonitrile:potassium phosphate buffer (30.0 mM; pH 5.5, 32.2:67.8% v/v) pumped at a flow rate of 1.0 mL/min and injection volume of 20.0 μL was employed. The proposed method was able to separate the ternary mixture in <10 min. The calibration curves of diflunisal, lesinurad, and febuxostat were linear over concentration ranges of 50.0-500.0, 50.0-700.0, and 20.0-700.0 ng/mL, respectively. Recovery percentages ranging from 98.1 to 101.3% with % relative standard deviation of <2% were obtained upon spiking to human plasma samples, indicating high bioanalytical applicability. Furthermore, the method was found to be excellent green when it was assessed according to Green Analytical Procedure Index and analytical Eco-Scale guidelines.