Standardization and quantitative analysis of Araucaria Heterophylla extract via an UPLC-MS/MS method and its formulation as an antibacterial phytonanoemulsion gel.

Skin infections are among the bacterial infections that present significant therapeutic challenges due to antibiotic resistance. Recently, herbal products clutched a significant attention as safe replacements for other medications but their low aqueous solubility and poor bioavailability are considered major challenges which could be circumvented via formulation. As a species of genera Araucaria, Araucaria Heterophylla possesses pharmacological activities such as antioxidant and antibacterial actions, and this study aimed to standardize the extract of the plant against 4'''methoxyamentoflavone (as a main component of the extract) through a validated UPLC-MS/MS method and evaluate its antibacterial activity, which was followed by loading the standardized extract into a nanoemulsion to form a phytonanoemulsion (PNE), where the design analysis and optimization were performed through a simplex lattice design. The optimized PNE (PNE 3) was then loaded into HPMC/Pluronic F-127 gel (in ratio 1:4) to sustain the release of the active constituent. The heightened penetrability of PNE 3 gel was visualized via confocal laser scanning microscopy, and its prolonged effect was proved thru an in vivo study conducted on male Wistar rats. A histopathological study revealed the safety of the formulation when applied topically. Thus, PNE gel could be a potentially broad-spectrum antibacterial drug delivery system.

Univariate calibrations with or without chemometric assistance for determination of drugs lacking peak maxima in their zero-order profiles.

Trandolapril has no sharp peak in its zero-order spectrum and therefore, it is difficult to be measured by direct spectrophotometry. In this manuscript, several univariate and multivariate spectrophotometric methods were developed and validated for determination of Trandolapril (TR) and Verapamil (VR) combination. The first method for measuring Trandolapril is Constant Multiplication-Spectrum Subtraction (CM-SS), where Trandolapril was measured at 210 nm in its zero-order curve after elimination of Verapamil spectrum. Second and third methods are two Base Points (2BP) and area under the curve (AUC) to measure Trandolapril concentration without depending on the shoulder peak. The fourth method for Trandolapril is Derivative Subtraction (DS) that utilizes the sharp peak appeared in the first order spectrum of Trandolapril. Verapamil was determined by two methods, Constant Multiplication (CM) and Derivative Subtraction-Constant Multiplication (DS-CM). Also, two multivariate methods were developed for measurement of the mixture, Partial Least Squares (PLS) and Principal Component Regression (PCR). All the developed methods were validated as per ICH guidelines and the results proved that the developed methods are accurate and selective. Moreover, a statistical comparison between the developed methods and a reference method was done. Also, One-way ANOVA statistical test was done between all the proposed univariate and multivariate spectrophotometric methods.

Determination of amlodipine and atorvastatin mixture by different spectrophotometric methods with or without regression equations.

Four new, simple, and reproducible spectrophotometric methods were developed and validated for the simultaneous determination of Amlodipine (AML) and Atorvastatin (AT) in bulk powder and pharmaceutical dosage form. The four methods include two progressive and two successive resolution techniques. The two progressive methods are Absorbance Subtraction (AS) and Amplitude Modulation (AM), while the two successive methods are Constant Value (CV) and Concentration Value. In the Concentration Value method, the concentration of the drugs is determined from the graphical representation without the use of regression equations. Linearity range for the two progressive methods was from 5 µg/mL-35 µg/mL while for the two successive methods was from 5 µg/mL-55 µg/mL. The four methods were validated according to the ICH guidelines and were found to be accurate, precise, and selective. The methods were also applied for determination of the mixture in the marketed pharmaceutical dosage form. Results obtained were compared with reported methods. Also, One-way ANOVA statistical test was done between all the proposed spectrophotometric methods where no significant differences were found.

Application of a Fast Separation Method for Anti-diabetics in Pharmaceuticals Using Monolithic Column: Comparative Study With Silica Based C-18 Particle Packed Column.

Run time is a predominant factor in HPLC for quality control laboratories especially if there is large number of samples have to be analyzed. Working at high flow rates cannot be attained with silica based particle packed column due to elevated backpressure issues. The use of monolithic column as an alternative to traditional C-18 column was tested for fast separation of pharmaceuticals, where the results were very competitive. The performance comparison of both columns was tested for separation of anti-diabetic combination containing Metformin, Pioglitazone and Glimepiride using Gliclazide as an internal standard. Working at high flow rates with less significant backpressure was obtained with the monolithic column where the run time was reduced from 6 min in traditional column to only 1 min in monolithic column with accepted resolution. The structure of the monolith contains many pores which can adapt the high flow rate of the mobile phase. Moreover, peak symmetry and equilibration time were more efficient with monolithic column.

Kinetic Profiling of the Hydrolytic Reaction of Benazepril: Metabolic Pathway Simulation.

A simple, specific, and rapid kinetic study of benazepril (BNZ) hydrolysis was developed and validated using HPLC. BNZ was degraded using 0.1 N sodium hydroxide at room temperature to produce benazeprilat, which is an active metabolite of BNZ and acts as an angiotensin-converting enzyme inhibitor. Analysis was carried out using an Athena C18 column (4.6 × 250 mm, 5 µm particle size). The mobile phase consists of a mixture of phosphate buffer (pH 4.5) and acetonitrile (53 + 47, v/v) at a flow rate of 1 mL/min. UV detection was accomplished at 242 nm using moexipril as the internal standard. The method was validated according to International Conference on Harmonization guidelines, and the calibration curve was linear over the range 10-100 µg/mL, with acceptable accuracy and precision. Kinetic profiling of the hydrolysis was shown to follow pseudo-first-order kinetics. The method was applied to the assay of BNZ in combined dosage form with no interference from other ingredients. The obtained results were statistically compared with those of the official method, showing no significant difference.

Full spectrum and selected spectrum based chemometric methods for the simultaneous determination of Cinnarizine and Dimenhydrinate in laboratory prepared mixtures and pharmaceutical dosage form.

Three chemometric methods namely, concentration residual augmented classical least squares (CRACLS), spectral residual augmented classical least squares (SRACLS) and partial least squares (PLS) were applied for the simultaneous quantitative determination of Cinnarizine and Dimenhydrinate in their binary mixtures. All techniques were applied with and without variable selection using genetic algorithm (GA) resulting in six models (CRACLS, GA-CRACLS, SRACLS, GA-SRACLS, PLS, GA-PLS). These models were applied for the simultaneous determination of the drugs in their laboratory prepared mixtures and pharmaceutical dosage form via handling their UV spectral data. It was found that GA based models are simpler and more robust than those built with the full spectral data. The proposed models were found to be simple, fast and require no preliminary separation steps; so they can be used for the routine analysis of this binary mixture in quality control laboratories.

Development and validation of different methods manipulating zero order and first order spectra for determination of the partially overlapped mixture benazepril and amlodipine: A comparative study.

Three simple, selective, and accurate spectrophotometric methods have been developed and then validated for the analysis of Benazepril (BENZ) and Amlodipine (AML) in bulk powder and pharmaceutical dosage form. The first method is the absorption factor (AF) for zero order and amplitude factor (P-F) for first order spectrum, where both BENZ and AML can be measured from their resolved zero order spectra at 238nm or from their first order spectra at 253nm. The second method is the constant multiplication coupled with constant subtraction (CM-CS) for zero order and successive derivative subtraction-constant multiplication (SDS-CM) for first order spectrum, where both BENZ and AML can be measured from their resolved zero order spectra at 240nm and 238nm, respectively, or from their first order spectra at 214nm and 253nm for Benazepril and Amlodipine respectively. The third method is the novel constant multiplication coupled with derivative zero crossing (CM-DZC) which is a stability indicating assay method for determination of Benazepril and Amlodipine in presence of the main degradation product of Benazepril which is Benazeprilate (BENZT). The three methods were validated as per the ICH guidelines and the standard curves were found to be linear in the range of 5-60µg/mL for Benazepril and 5-30 for Amlodipine, with well accepted mean correlation coefficient for each analyte. The intra-day and inter-day precision and accuracy results were well within the acceptable limits.

Effect of Perioperative ß-Blockers on Pulmonary Complications among Patients with Chronic Obstructive Pulmonary Disease Undergoing Lung Resection Surgery.

The aim of this study is to determine if COPD patients undergoing lung resection with perioperative ß-blocker use are more likely to suffer postoperative COPD exacerbations than those that did not receive perioperative ß-blockers. Methods. A historical cohort study of COPD patients, undergoing lung resection surgery at Memorial Sloan-Kettering Cancer Center between 2002 and 2006. Primary outcomes were the rate of postoperative COPD exacerbations, defined as any initiation or increase of glucocorticoids for documented bronchospasm. Results. 520 patients with COPD were identified who underwent lung resection. Of these, 205 (39%) received perioperative ß-blockers and 315 (61%) did not. COPD was mild among 361 patients (69% of all patients), moderate in 117 patients (23%), and severe in 42 patients (8%). COPD exacerbations occurred among 11 (5.4%) patients who received perioperative ß-blockers and among 20 (6.3%) patients who did not. Secondary outcomes, which included respiratory failure, 30-day mortality, and the presence or absence of any cardiovascular complication, ICU transfer, cardiovascular complication, or readmission within 30 days, did not differ in prevalence between the two groups. Conclusions. This study implies that perioperative ß-blockers use among COPD patients undergoing lung resection surgery does not impact the rate of exacerbations.

Comparative study between univariate spectrophotometry and multivariate calibration as analytical tools for simultaneous quantitation of Moexipril and Hydrochlorothiazide.

Three simple, accurate, reproducible, and selective methods have been developed and subsequently validated for the simultaneous determination of Moexipril (MOX) and Hydrochlorothiazide (HCTZ) in pharmaceutical dosage form. The first method is the new extended ratio subtraction method (EXRSM) coupled to ratio subtraction method (RSM) for determination of both drugs in commercial dosage form. The second and third methods are multivariate calibration which include Principal Component Regression (PCR) and Partial Least Squares (PLSs). A detailed validation of the methods was performed following the ICH guidelines and the standard curves were found to be linear in the range of 10-60 and 2-30 for MOX and HCTZ in EXRSM method, respectively, with well accepted mean correlation coefficient for each analyte. The intra-day and inter-day precision and accuracy results were well within the acceptable limits.

Comparative study between univariate spectrophotometry and multivariate calibration as analytical tools for quantitation of Benazepril alone and in combination with Amlodipine.

Four simple, accurate, reproducible, and selective methods have been developed and subsequently validated for the determination of Benazepril (BENZ) alone and in combination with Amlodipine (AML) in pharmaceutical dosage form. The first method is pH induced difference spectrophotometry, where BENZ can be measured in presence of AML as it showed maximum absorption at 237nm and 241nm in 0.1N HCl and 0.1N NaOH, respectively, while AML has no wavelength shift in both solvents. The second method is the new Extended Ratio Subtraction Method (EXRSM) coupled to Ratio Subtraction Method (RSM) for determination of both drugs in commercial dosage form. The third and fourth methods are multivariate calibration which include Principal Component Regression (PCR) and Partial Least Squares (PLSs). A detailed validation of the methods was performed following the ICH guidelines and the standard curves were found to be linear in the range of 2-30µg/mL for BENZ in difference and extended ratio subtraction spectrophotometric method, and 5-30 for AML in EXRSM method, with well accepted mean correlation coefficient for each analyte. The intra-day and inter-day precision and accuracy results were well within the acceptable limits.