UV-VIS imaging-based investigation of API concentration fluctuation caused by the sticking behaviour of pharmaceutical powder blends.

Surface powder sticking in pharmaceutical mixing vessels poses a risk to the uniformity and quality of drug formulations. This study explores methods for evaluating the amount of pharmaceutical powder mixtures adhering to the metallic surfaces. Binary powder blends consisting of amlodipine and microcrystalline cellulose (MCC) were used to investigate the effect of the mixing order on the adherence to the vessel wall. Elevated API concentrations were measured on the wall and within the dislodged material from the surface, regardless of the mixing order of the components. UV imaging was used to determine the particle size and the distribution of the API on the metallic surface. The results were compared to chemical maps obtained by Raman chemical imaging. The combination of UV and VIS imaging enabled the rapid acquisition of chemical maps, covering a substantially large area representative of the analysed sample. UV imaging was also applied in tablet inspection to detect tablets that fail to meet the content uniformity criteria. The results present powder adherence as a possible source of poor content uniformity, highlighting the need for 100% inspection of pharmaceutical products to ensure product quality and safety.

The Applicability of Chromatographic Retention Modeling on Chiral Stationary Phases in Reverse-Phase Mode: A Case Study for Ezetimibe and Its Impurities.

Mechanistic modeling is useful for predicting and modulating selectivity even in early chromatographic method development. This approach is also in accordance with current analytical quality using design principles and is highly welcomed by the authorities. The aim of this study was to investigate the separation behavior of two different types of chiral stationary phases (CSPs) for the separation of ezetimibe and its related substances using the mechanistic retention modeling approach offered by the Drylab software (version 4.5) package. Based on the obtained results, both CSPs presented with chemoselectivity towards the impurities of ezetimibe. The cyclodextrin-based CSP displayed a higher separation capacity and was able to separate seven related substances from the active pharmaceutical ingredient, while the cellulose-based column enabled the baseline resolution of six impurities from ezetimibe. Generally, the accuracy of predicted retention times was lower for the polysaccharide CSP, which could indicate the presence of additional secondary interactions between the analytes and the CSP. It was also demonstrated that the combination of mechanistic modeling and an experimental design approach can be applied to method development on CSPs in reverse-phase mode. The applicability of the methods was tested on spiked artificial placebo samples, while intraday and long-term (2 years) method repeatability was also challenged through comparing the obtained retention times and resolution values. The results indicated the excellent robustness of the selected setpoints. Overall, our findings indicate that the chiral columns could offer orthogonal selectivity to traditional reverse-phase columns for the separation of structurally similar compounds.

In-line particle size measurement during granule fluidization using convolutional neural network-aided process imaging.

This paper presents a machine learning-based image analysis method to monitor the particle size distribution of fluidized granules. The key components of the direct imaging system are a rigid fiber-optic endoscope, a light source and a high-speed camera, which allow for real-time monitoring of the granules. The system was implemented into a custom-made 3D-printed device that could reproduce the particle movement characteristic in a fluidized-bed granulator. The suitability of the method was evaluated by determining the particle size distribution (PSD) of various granule mixtures within the 100-2000 µm size range. The convolutional neural network-based software was able to successfully detect the granules that were in focus despite the dense flow of the particles. The volumetric PSDs were compared with off-line reference measurements obtained by dynamic image analysis and laser diffraction. Similar trends were observed across the PSDs acquired with all three methods. The results of this study demonstrate the feasibility of performing real-time particle size analysis using machine vision as an in-line process analytical technology (PAT) tool.

Analytical quality by design-compliant retention modeling for exploring column interchangeabilities in separating ezetimibe and its related substances.

There are several potential advantages of using experimental design-based retention modeling for chromatographic method development. Most importantly, through the model-delivered systematic understanding (Design Spaces), users can benefit from increased method consistency, flexibility and robustness that can efficiently be achieved at lesser amount of development time. As a result, modeling tools have always been great supplementary assets and welcomed by both the pharmaceutical industry and the regulatory authorities. Most recently published chapters of ICH however - Q2(R2) and Q14 (both currently drafts) - evidence a further paradigm shift, specifying the elements of model-based development strategies in the so-called "enhanced approach". The main aim of this study was to investigate the impact of stationary phase chemistries on chromatographic method performance in the application example of ezetimibe and its related substances. A commercial modeling software package (DryLab®) was used to outline three-dimensional experimental design frameworks and acquire model Design Spaces (DSs) of 9 tested columns. This was done by performing 12 input calibration experiments per column, systematically changing critical method parameters (CMPs) as variables such as the gradient time (tG), temperature (T) and the ternary composition (tC) of the mobile phase. The constructed models allowed studying retention behaviors of selected analytes within each separation systems. In the first part of our work, we performed single optimizations for all nine stationary phases with substantially different surface modifications based on their highest achievable critical resolution values. For these optimum points in silico robustness testing was performed, clearly showing a change of CMPs, depending on the column, and specified optimum setpoint. In the second part of our work, we simultaneously compared the three-dimensional virtual separation models to identify all method parameter combinations that could provide at least baseline separation (Rs, crit.>1.50). These overlapping areas between the models described a common method operational design region (MODR) where columns were considered completely interchangeable - in terms of their baseline resolving capability - regardless of their exact physicochemical properties. A final optimized, column-independent working point within the common MODR was selected for verification. Indeed, experimental chromatograms showed excellent agreement with the model; all columns in the common condition were able to yield critical resolution values higher than 2.0, only their retentivity (elution window of peaks) was found different in some cases. Our results underline that a profound understanding of the separation process is of utmost importance andthat in some cases, adequate selectivity is achievable on various stationary phases.

Insulin Complexation with Cyclodextrins-A Molecular Modeling Approach.

Around 5% of the population of the world is affected with the disease called diabetes mellitus. The main medication of the diabetes is the insulin; the active form is the insulin monomer, which is an instable molecule, because the long storage time, or the high temperature, can cause the monomer insulin to adapt an alternative fold, rich in ß-sheets, which is pharmaceutically inactive. The aim of this study is to form different insulin complexes with all the cyclodextrin used for pharmaceutical excipients (native cyclodextrin, methyl, hydroxyethyl, hydroxypropyl and sulfobutylether substituted ß-cyclodextrin), in silico condition, with the AutoDock molecular modeling program, to determine the best type of cyclodextrin or cyclodextrin derivate to form a complex with an insulin monomer, to predict the molar ratio, the conformation of the complex, and the intermolecular hydrogen bonds formed between the cyclodextrin and the insulin. From the results calculated by the AutoDock program it can be predicted that insulin can make a stable complex with 5-7 molecules of hydroxypropyl-ß-cyclodextrin or sulfobutylether-ß-cyclodextrin, and by forming a complex potentially can prevent or delay the amyloid fibrillation of the insulin and increase the stability of the molecule.

Computer-assisted UHPLC method development and optimization for the determination of albendazole and its related substances.

Computer-aided ultrahigh performance liquid chromatographic (UHPLC) method development and optimization was undertaken in order to replace an underperforming European Pharmacopoeia method for the determination of albendazole and its related substances. In the preliminary screening, a temperature-gradient time bidimensional model was chosen to aid selection of the proper stationary phase. Hereinafter temperature-gradient time-ternary composition and temperature-gradient time-pH tridimensional models were applied for the optimization of critical method parameters. The simulation and in silico robustness testing were realized using DryLab modeling software. The final method was validated for quantification of impurities and assay of the active substance according to the current ICH guidance. The validated methods were tested on a real, commercial tablet formulation. The experimental design-based and software-assisted method development proved to be a fast and reliable way of replacing a method with inadequate selectivity and long runtime with a robust UHPLC-based method, which offers baseline separation for all monitored impurities in 10 min. Results confirm that software-based chromatographic modelling can not only speed up the analytical method development process, but also improve the reliability of the developed method.

Preparation and Characterization of Fenofibrate-Loaded PVP Electrospun Microfibrous Sheets.

Fenofibrate-loaded electrospun microfibrous sheets were prepared in an attempt to enhance the dissolution of the poorly soluble antihyperlipidemic agent and to improve its bioavailability. Physicochemical changes that appeared during the electrospinning process were monitored using a wide array of solid-state characterization techniques, including attenuated total reflectance Fourier-transformed infrared spectroscopy and positron annihilation lifetime spectroscopy, while fiber morphology was monitored via scanning electron microscopy. Dissolution studies carried out both in 0.025 M sodium dodecyl sulfate and in water revealed an immediate release of the active agent, with an approximately 40-fold release rate enhancement in water when compared to the micronized active agent. The dramatic increase in dissolution was attributed partially to the amorphous form of the originally crystalline active agent and the rapid disintegration of the electrospun microfibrous sheet due to its high surface area and porosity. The obtained results could pave the way for a formulation of the frequently used antihyperlipidemic agent with increased bioavailability.

Formulation and Characterization of Aceclofenac-Loaded Nanofiber Based Orally Dissolving Webs.

Aceclofenac-loaded poly(vinyl-pyrrolidone)-based nanofiber formulations were prepared by electrospinning to obtain drug-loaded orally disintegrating webs to enhance the solubility and dissolution rate of the poorly soluble anti-inflammatory active that belongs to the BCS Class-II. Triethanolamine-containing ternary composite of aceclofenac-poly(vinyl-pyrrolidone) nanofibers were formulated to exert the synergistic effect on the drug-dissolution improvement. The composition and the electrospinning parameters were changed to select the fibrous sample of optimum fiber characteristics. To determine the morphology of the nanofibers, scanning electron microscopy was used. Fourier transform infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC) were applied for the solid-state characterization of the samples, while the drug release profile was followed by the in vitro dissolution test. The nanofibrous formulations had diameters in the range of few hundred nanometers. FT-IR spectra and DSC thermograms indicated the amorphization of aceclofenac, which resulted in a rapid release of the active substance. The characteristics of the selected ternary fiber composition (10 mg/g aceclofenac, 1% w/w triethanolamine, 15% w/w PVPK90) were found to be suitable for obtaining orally dissolving webs of fast dissolution and potential oral absorption.

Effect of Vipera ammodytes ammodytes Snake Venom on the Human Cytokine Network.

Local inflammation is a well-known symptom of envenomation by snakes of the family Viperidae, attributed primarily to the phospholipase A2s, metalloproteinases and L-amino acid oxidases contained in their venom. The inflammatory effect of snake venoms has been associated with a marked increase of the cytokines IL-1β, IL-6, IL-8, IL-10 and TNF-α. To determine the impact of Vipera ammodytes ammodytes snake venom on the expression of inflammation-related genes, we incubated human U937 monocyte cells with dilutions of snake venom. Gene expression was quantified for 28 different genes using a TaqMan® Array Human Cytokine Network 96-well Plate in a RT-qPCR system. Our results have demonstrated that 1.0 μg/mL Vipera ammodytes ammodytes venom solution induces a notable change in the expression of several cytokine network genes. Among the upregulated genes, there were several that encode interleukins, interferons, and tumor necrosis factors. We further report the downregulation of three interleukin-related genes. Our findings come as supportive information for the known complex effect of snake venoms on the human cytokine network. It also provides relevant new information regarding the expression of genes that have not been previously associated with the effect of snake venoms.

Application of SeDeM expert systems in preformulation studies of pediatric ibuprofen ODT tablets.

Pediatric, ibuprofen containing orodispersible tablets (ODTs) were prepared using the SeDeM expert system methodology. In order to facilitate formulation, directly compressible ibuprofen was employed (Ibuprofen DC 8TM) and characterized using its SeDeM profile. The mannitol based superdisintegrant Ludiflash® was characterized by the SeDeM-ODT expert system, which also allowed calculation of the optimal excipient concentration in order to obtain suitable tablet hardness and disintegration time. After adding a sweetener and a standard combination of lubricants, the optimized formulation was directly compressed into tablets and evaluated in terms of tablet hardness, friability, disintegration time and dissolution profile. The SeDeM method was applied to determine the amount of corrective excipient (Ludiflash®) required for the compression of Ibuprofen DC 85TM in order to achieve suitable ODTs. Adequate tablet hardness, disintegration time, friability and dissolution profiles were found during tablet evaluation.

Preparation and characterization of nanofibrous sheets for enhanced oral dissolution of nebivolol hydrochloride.

Nebivolol-loaded electrospun nanofibrous sheets were prepared for the dissolution enhancement of the active with the aim of improving its oral bioavailability. Physicochemical characterization of nanofibers including differential scanning calorimetry, attenuated total reflectance Fourier transform infrared spectroscopy and positron annihilation lifetime spectroscopy were carried out in order to track the physicochemical changes related to the electrospinning process. The obtained results unanimously indicated the amorphous transition of nebivolol as a result of electrospinning, furthermore supramolecular ordering of chains of polyvinyl alcohol matrix could be revealed by positron annihilation lifetime spectroscopy. The crystalline-amorphous conversion of the active, along with the increased specific surface area of the nanofibers enabled rapid and complete dissolution. More than twice amount of active released from the fibrous sheets than from the commercial tablets. In contrast to the control tablets, the dissolution was complete and was not influenced by the pH of the applied media.

Study of the effect of formulation variables on the characteristics of combination tablets containing enalapril maleate and indapamide as active substances using experimental design.

To evaluate the influence of different variables on tablet formulations containing enalapril maleate and indapamide as active substances, two separate experimental designs were employed: one for evaluating powder properties and the other for tablet characteristics. Because of the low active pharmaceutical ingredient content, it was hypothesized that both powder and tablet properties could be determined only by the characteristics of excipients. In order to test this assumption, both experimental designs were done with placebo mixtures. The optimized formulation was then evaluated both with and without APIs. Results indicated that filler and lubricant percentage, along with compression force, were the most important variables during the formulation study. The optimized formulation showed similar characteristics in both cases for all responses, except for angle of repose and friability where only minor differences were observed. The combination of the applied approaches (using placebo composition and fractional experimental design) proved to be efficient, cost effective and time saving.

Simultaneous quantification of related substances of perindopril tert-butylamine using a novel stability indicating liquid chromatographic method.

A novel stability indicating gradient reverse-phased high-performance liquid chromatographic method has been developed for the quantification of impurities of perindopril tert-butylamine (PER) in pharmaceutical dosage form. Separation of the active substance and its known (Impurities B, C, D, E, F) and unknown impurities was achieved on a BDS Hypersil C18 column (250 mm × 4.6 mm, 5 µm), thermostated at 70°C, using a mobile phase comprised of aqueous solution of sodium 1-heptanesulfonate adjusted to pH 2 with perchloric acid and acetonitrile. The flow rate was maintained at 1.5 mL min(-1), injection volume of 20 µL was utilized and detection of analytes was performed at 215 nm. The developed method was validated in accordance with current ICH Guidelines for all suggested parameters, including forced degradation studies and proved to be linear, accurate, precise and suitable for the impurity testing of PER, being subsequently applied during on-going stability studies of a newly developed generic formulation.

The role of co-spray-drying procedure in the preformulation of intranasal propranolol hydrochloride.

The use of dry powder formulations presents an alternative through which to achieve better deposition and residence time in the nasal cavity, increased stability and possible absorption enhancement. The most important factors involved in the preformulation are particle size and physical stability. Propranolol hydrochloride a model drug was subjected to spray-drying technology to form an intranasal dry powder. Particle size reduction of the drug was carried out by integration (spray-drying) methods, using different excipients. The micrometric properties were characterized by size and morphology. The structure was determined through the use of differential scanning calorimetry, X-ray powder diffraction and Fourier transform infrared spectroscopy investigations. It was concluded that the intranasal dry powder formulation of propranolol hydrochloride can be achieved with a suitable particle size without polymorph modification or chemical decomposition.

Development of new formulation and its evaluation by capillary electrophoresis of tablets containing tramadol hydrochloride and paracetamol.

CONTEXT: A quick and efficient method to eliminate pain is combining complementary action and substances with synergic effect. Such an association is the one between tramadol hydrochloride and paracetamol, in which the rapid reaction time of the paracetamol is combined with the long-term effect of the tramadol hydrochloride. OBJECTIVE: Our aim was to develop and characterize alternative tablet formulations containing tramadol hydrochloride 37.5 mg and paracetamol 325 mg with different excipients in different ratio, and also the development of a new electrophoretic method for the quantitative determination of the active substances. MATERIALS AND METHODS: The tablets were evaluated for physical characteristics (weight, thickness, diameter, mechanical strength, friability, disintegration time), drug content and dissolution following Ph.Eur.7 and USP 35 guidelines. A new capillary electrophoretic method was developed for the determination of the two active substances. RESULTS: Capillary electrophoresis proved to be an efficient method for the determination of drug content and also for the dissolution profile. The two substances were separated based on the differences between their own electrophoretic mobilities, and determined in UV at two different wavelengths. CONCLUSIONS: Tablet formulation proved to be a significant factor in quality of tramadol hydrochloride/paracetamol tablets, as considerable differences between tablets containing different excipients were found; while capillary electrophoresis can be considered a useful alternative for the quantitative determination of tramadol hydrochloride/paracetamol combinations.

[Stability of some medicinal solutions with captopril]. / Stabilitatea unor soluti orale de captopril.

UNLABELLED: The aim of the study was to investigate the stability of some oral liquid formulations containing 1 mg/ml captopril. MATERIAL AND METHOD: The oral solutions were prepared using captopril substance, keeping the formulation as simple as possible to avoid potentially undesirable excipients. Samples were stored for 39 days below 8 degrees C and at 22 +/- 3 degrees C and analysed for physical, chemical and microbiological stability. RESULTS: The formulations with ascorbic acid are stable for seven days either at 8 and 22 degrees C and could be prepared in hospital pharmacy as a more safely alternative to children terapy with tablets powders.