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1.
Sci Data ; 10(1): 237, 2023 04 26.
Article in English | MEDLINE | ID: mdl-37185601

ABSTRACT

This paper describes a dataset capturing insider trading activity at publicly traded companies. Investors and investment analysts demand this information because executives, directors and large shareholders are expected to have more intimate knowledge of their company's prospects than outsiders. Insider stock sales and purchases may reveal information about the firm's business not disclosed in financial statements. They may also convey new information predictive of stock price movements if insiders can better interpret public information about the firm. Since mid-2003, the Securities and Exchange Commission has made these insider trading reports available to the public in a structured format; however, most academic papers use proprietary commercial databases instead of regulatory filings directly. This makes replication challenging as the data manipulation and aggregation processes are opaque and historical records could be altered by the database provider over time. To overcome these limitations, the presented dataset is created from original regulatory filings; it is updated daily and includes all information reported by insiders without alteration.

2.
Int J Pharm ; 586: 119593, 2020 Aug 30.
Article in English | MEDLINE | ID: mdl-32622813

ABSTRACT

The effect of different frequencies and waveforms was investigated for the first time on alternating current electrospinning (ACES). PVPVA64, a polyvinylpyrrolidone-vinyl acetate copolymer was selected for the experiments as an important matrix for amorphous solid dispersions but never processed with ACES. It has been proved that ACES could be operated in a wide range of frequencies (40-250 Hz) and using different waveforms (sinusoidal, square, triangle, saw tooth) without significant changes in fiber morphology. Nevertheless, deterioration of the fiber formation process could be also observed especially at high frequencies. The developed PVPVA64-based fibers containing small amounts of additives (polyethylene oxide (PEO) and sodium dodecyl sulfate (SDS)) served as an excellent carrier for spironolactone (SPIR), a poorly soluble antihypertensive drug. As a result of the amorphously dispersed SPIR and the large surface area of the AC electrospun fibers immediate drug release could be achieved.


Subject(s)
Electricity , Polyethylene Glycols , Drug Liberation , Polymers , Povidone , Solubility
3.
Int J Pharm ; 581: 119297, 2020 May 15.
Article in English | MEDLINE | ID: mdl-32243964

ABSTRACT

An end-to-end continuous pharmaceutical manufacturing process was developed for the production of conventional direct compressed tablets on a proof-of-concept level for the first time. The output reaction mixture of the flow synthesis of acetylsalicylic acid was crystallized continuously in a mixed suspension mixed product removal crystallizer. The crystallizer was directly connected to a continuous filtration carousel device, thus the crystallization, filtration and drying of acetylsalicylic acid (ASA) was carried out in an integrated 2-step process. Steady state was reached during longer operations and the interaction of process parameters was evaluated in a series of experiments. The filtered crystals were ready for further processing in a following continuous blending and tableting experiment due to the good flowability of the material. The ASA collected during the crystallization-filtration experiments was fed into a continuous twin-screw blender along with microcrystalline cellulose as tableting excipient. After continuous blending Near-Infrared spectroscopy was applied to in-line analyze the drug content of the powder mixture. A belt conveyor carried the mixture towards an eccentric lab-scale tablet press, which continuously produced 500 mg ASA-loaded compressed tablets of 100 mg dose strength. Thus, starting from raw materials, the final drug product was obtained by continuous manufacturing steps with appropriate quality.


Subject(s)
Aspirin/chemical synthesis , Chemistry, Pharmaceutical/methods , Compressive Strength , Crystallization/methods , Aspirin/analysis , Cellulose/analysis , Cellulose/chemical synthesis , Filtration/methods , Spectroscopy, Near-Infrared/methods , Tablets
4.
Int J Pharm ; 569: 118593, 2019 Oct 05.
Article in English | MEDLINE | ID: mdl-31398371

ABSTRACT

The objectives of this work were to develop meloxicam based amorphous solid dispersion through electrospinning technique and evaluate the effect of the polymeric matrix on the physicochemical properties of the fibers and the downstream processing ability to orodispersible dosage forms. Drug - polymer interactions formed between Eudragit E and meloxicam, confirmed through Raman and 1HNMR spectra, enabled the development of fibers from ethanol, thus allowing an increased production rate compared to PVPk30 where a DMF:THF solvent system was suitable. Microflux dissolution-permeation studies showed a significantly higher diffusion from amorphous solid dispersions compared to crystalline meloxicam. The flux through the membrane was influenced by the polymers only under basic conditions, where the precipitation of Eudragit E limited the complete resolubilization of the active ingredient. This phenomenon was not observed during large volume conventional dissolution testing. The effect of formulation on long term stability could not be highlighted as all products were stable up to 15 months, stored in closed holders at 25 °C ±â€¯2 °C and 50%RH ±â€¯10%. The increased surface area of fibers enabled tablet preparation with low pressures due to favorable bonding between particles during compression. PVPk30 formulation presented higher tabletability and compactability, as higher tensile strength compacts could be prepared. Eudragit E formulation had lower detachment and ejection stress, suggesting a lower sticking tendency during tableting. The presence of HPßCD in PVPk30 formulation offered improved morphological features of the fibers, however no significant effect was observed on dissolution, permeation or mechanical properties. Downstream processing was guided by polymer mechanical properties and solubility, thus PVPk30 fibers could be delivered in the form of orodispersible webs and conventional tablets, whereas Eudragit E fibers as orodispersible tablets.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/chemistry , Meloxicam/chemistry , Drug Compounding/methods , Polymers/chemistry , Solubility , Tablets
5.
Int J Pharm ; 567: 118473, 2019 Aug 15.
Article in English | MEDLINE | ID: mdl-31252149

ABSTRACT

The aim of this work was to develop a PAT platform consisting of four complementary instruments for the characterization of electrospun amorphous solid dispersions with meloxicam. The investigated methods, namely NIR spectroscopy, Raman spectroscopy, Colorimetry and Image analysis were tested and compared considering the ability to quantify the active pharmaceutical ingredient and to detect production errors reflected in inhomogeneous deposition of fibers. Based on individual performance the calculated RMSEP values ranged between 0.654% and 2.292%. Mid-level data fusion consisting of data compression through latent variables and application of ANN for regression purposes proved efficient, yielding an RMSEP value of 0.153%. Under these conditions the model could be validated accordingly on the full calibration range. The complementarity of the PAT tools, demonstrated from the perspective of captured variability and outlier detection ability, contributed to model performance enhancement through data fusion. To the best of the author's knowledge, this is the first application of data fusion in the field of PAT for efficient handling of big-analytical-data provided by high-throughput instruments.


Subject(s)
Neural Networks, Computer , Technology, Pharmaceutical/methods , Colorimetry , Meloxicam , Microscopy/methods , Photography , Powder Diffraction , Spectroscopy, Near-Infrared , Spectrum Analysis, Raman , Technology, Pharmaceutical/instrumentation , X-Ray Diffraction
7.
Int J Pharm ; 561: 219-227, 2019 Apr 20.
Article in English | MEDLINE | ID: mdl-30844423

ABSTRACT

Corona alternating current electrospinning (C-ACES), a scaled-up productivity electrospinning method was developed by combining the intense forces of the alternating electrostatic field and a sharp-edged spinneret design with increased free surface. C-ACES reached two orders of magnitude higher productivity (up to 1200 mL/h) than the classical single needle direct current electrospinning (DCES) without any alteration of fiber properties. Polyvinylpyrrolidone K90 (PVPK90), a water soluble high molecular weight nonionic polymer was processed for the first time with single needle alternating current electrospinning (ACES) and C-ACES in order to prepare fast dissolving amorphous solid dispersions of spironolactone (SPIR), a poorly water-soluble antihypertensive model drug. The limited spinnability of PVPK90 with AC high voltage could only be resolved by optimizing the solution conductivity with organophilic salts such as sodium dodecyl sulfate (SDS) demonstrating the importance of conductivity during ACES. The effects of varied solution properties (composition and conductivity) and scaling-up were investigated by SEM imaging. Solid state analyses revealed that SPIR was dispersed in an amorphous form in the fibrous mats. In vitro dissolution tests showed ultrafast drug release in case of the amorphous formulations even when prepared with scaled-up C-ACES. Besides the enhancement of conductivity SDS also prevents SPIR from precipitation from the dissolution media due to its solubilization ability.


Subject(s)
Efficiency , Electricity , Technology, Pharmaceutical/methods , Drug Carriers/chemistry , Drug Compounding/methods , Drug Liberation , Povidone/chemistry , Spironolactone/chemistry
8.
Eur J Pharm Sci ; 130: 91-99, 2019 Mar 15.
Article in English | MEDLINE | ID: mdl-30684658

ABSTRACT

An orally dissolving web (ODW) formulation of poorly soluble carvedilol (CAR) was developed and manufactured continuously using electrospinning (ES) as a key technology. Phase solubility tests revealed that hydroxypropyl-ß-cyclodextrin (HPßCD) solubilizer alone cannot ensure sufficient solubility (6.25 mg CAR in 20 mL) in the oral cavity even if citric acid was present to ionize the basic drug. In turn, electrospun amorphous nanofibers of polyvinylpyrrolidone K30 (PVPK30) and CAR exhibited notable supersaturation of the drug in the presence of citric acid. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD) confirmed the amorphous state of CAR. The final ODW was prepared by layering the nanofibers onto pullulan, a well-soluble polysaccharide film carrying citric acid. The double-layered formulation showed ultrafast disintegration and dissolution modeling the oral cavity meeting regulatory requirements (<30 s). The continuous production was accomplished using our recently developed continuous model system by controlled deposition of the nanofibers onto the carrier film strained to a wheel collector and followed by cutting into final dosage units. Performance tests of the continuous system revealed satisfactory content uniformity over time (average acceptance value = 9.45), while residual solvent content measurements showed trace amounts of ethanol (EtOH) after production and acceptable dimethyl-formamide (DMF) content with secondary drying at room temperature. The presented work demonstrates how ES can be part of a continuous manufacturing system as an advanced drying tool during the formulation of challenging drugs.


Subject(s)
2-Hydroxypropyl-beta-cyclodextrin/chemical synthesis , Carvedilol/chemical synthesis , Chemistry, Pharmaceutical/methods , Citric Acid/chemical synthesis , Glucans/chemical synthesis , Nanofibers/chemistry , 2-Hydroxypropyl-beta-cyclodextrin/pharmacokinetics , Calorimetry, Differential Scanning/methods , Carvedilol/pharmacokinetics , Citric Acid/pharmacokinetics , Glucans/pharmacokinetics , Solubility , X-Ray Diffraction/methods
9.
Eur J Pharm Sci ; 129: 110-123, 2019 Mar 01.
Article in English | MEDLINE | ID: mdl-30610954

ABSTRACT

The three dimensional printing (3DP) in the pharmaceutical domain constitutes an alternative, innovative approach compared to the conventional production methods. Fused deposition modelling (FDM), is a simple, cost-effective 3DP technique, however the range of pharmaceutical excipients that can be applied for this methodology is restricted. The study set to define the requirements of the FDM printability, using as technical support custom made, pharmaceutical polymer based filaments and to evaluate if these new dosage forms can live up to the current GMP/GCP quality standards. Formulation rationale was assessed in accordance to the apparatus functionality. Blends were pre-screened based on the processability under the API (carvedilol) thermogravimetric analysis determined critical limit. The technological process implied the use of FDM coupled with hot melt extrusion (HME), while printability was defined by means of thermal, rheological and mechanical measurements. From the pharmaceutical standpoint, the consistency of the in vitro dissolution kinetics was monitored 'at release' and 'in stability', while the print process impact was evaluated based on the previously determined processability potential. Results showed that FDM printability is multifactorial, with brittleness and melt viscosity as primary limitation factors. The increase in shear-thinning and flexural modulus can enable broader processability intervals, which in turn proved to be essential in limiting degradation product formation. The 3DP tablets released the API in an extended rate, however the temperature and humidity along production and storage should be carefully considered as it may affect the final product quality in time. In conclusion, HME + FDM can be considered as an alternative production methodology, with prospects of applicability in the clinical sector, however for some formulations extensive packaging development will be necessary before confirming their suitability.


Subject(s)
Polymers/chemistry , Tablets/chemistry , Drug Liberation , Drug Stability , Excipients/chemistry , Printing, Three-Dimensional , Solubility , Technology, Pharmaceutical/methods , Temperature
10.
Pharmaceutics ; 10(3)2018 Aug 02.
Article in English | MEDLINE | ID: mdl-30072667

ABSTRACT

Low-dose tablet formulations were produced with excellent homogeneity based on drug-loaded electrospun fibers prepared by single-needle as well as scaled-up electrospinning (SNES and HSES). Carvedilol (CAR), a BCS II class compound, served as the model drug while poly (vinylpyrrolidone-co-vinyl acetate) (PVPVA64) was adopted as the fiber-forming polymer. Scanning electron microscopy (SEM) imaging was used to study the morphology of HSES and SNES samples. Different homogenization techniques were compared to maximize homogeneity: mixing in plastic bags and in a high-shear granulator resulting in low-shear mixing (LSM) and high-shear mixing (HSM). Drug content and homogeneity of the tablets were measured by UV-Vis spectrometry, the results revealed acceptably low-dose fluctuations especially with formulations homogenized with HSM. Sieve analysis was used on the final LSM and HSM powder mixtures in order to elucidate the observed differences between tablet homogeneity. Tablets containing drug-loaded electrospun fibers were also studied by Raman mapping demonstrating evenly distributed CAR within the corpus.

11.
Eur J Pharm Sci ; 114: 310-317, 2018 Mar 01.
Article in English | MEDLINE | ID: mdl-29305981

ABSTRACT

In this study, brand and four generic formulations of telmisartan, an antihypertensive drug, were used in in vitro simultaneous dissolution-absorption, investigating the effect of different formulation additives on dissolution and on absorption through an artificial membrane. The in vitro test was found to be sensitive enough to show even small differences between brand and generic formulations caused by the use of different excipients. By only changing the type of filler from sorbitol to mannitol in the formulation, the flux through the membrane was reduced by approximately 10%. Changing the salt forming agent as well resulted in approximately 20% of flux reduction compared to the brand formulation. This significant difference was clearly shown in the published in vivo results as well. The use of additional lactose monohydrate in the formulation also leads to approximately 10% reduction in flux. The results show that by changing excipients, the dissolution of telmisartan was not altered significantly, but the flux through the membrane was found to be significantly changed. These results pointed out the limitations of traditional USP dissolution tests and emphasized the importance of simultaneously measuring dissolution and absorption, which allows the complex effect of formulation excipients on both processes to be measured. Moreover, the in vivo predictive power of the simultaneous dissolution-absorption test was demonstrated by comparing the in vitro fluxes to in vivo bioequivalence study results.


Subject(s)
Benzimidazoles/chemistry , Benzimidazoles/metabolism , Benzoates/chemistry , Benzoates/metabolism , Drug Liberation , Drugs, Generic/chemistry , Drugs, Generic/metabolism , Antihypertensive Agents/chemistry , Antihypertensive Agents/metabolism , Biological Availability , Drug Compounding , Drug Liberation/physiology , Membranes, Artificial , Solubility , Telmisartan
12.
J Nat Prod ; 80(6): 1909-1917, 2017 06 23.
Article in English | MEDLINE | ID: mdl-28581297

ABSTRACT

A feasible and enantioselective total synthesis of (-)-trans-dihydronarciclasine [(-)-1], a highly biologically active alkaloid, was devised starting from vanillin (8). The key step of this new synthesis was an asymmetric, organocatalytic Michael addition, in which an optically active nitropentanone [(-)-13] was obtained from a butenone derivative (12). Excellent enantioselectivity (>99% ee) was achieved using the (8S,9S)-9-amino(9-deoxy)epiquinine (16) organocatalyst. The target molecule can be prepared in 13 steps from compound (-)-13. The total synthesis has provided a facile and first access to the ent-form of naturally occurring (+)-trans-dihydronarciclasine, a highly potent cytostatic alkaloid.


Subject(s)
Alkaloids/chemical synthesis , Amaryllidaceae Alkaloids/chemical synthesis , Alkaloids/chemistry , Amaryllidaceae Alkaloids/chemistry , Catalysis , Crystallography, X-Ray , Molecular Structure , Stereoisomerism
13.
Drug Dev Ind Pharm ; 43(7): 1126-1133, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28274133

ABSTRACT

The bioavailability of the anthelminthic flubendazole was remarkably enhanced in comparison with the pure crystalline drug by developing completely amorphous electrospun nanofibres with a matrix consisting of hydroxypropyl-ß-cyclodextrin and polyvinylpyrrolidone. The thus produced formulations can potentially be active against macrofilariae parasites causing tropical diseases, for example, river blindness and elephantiasis, which affect altogether more than a hundred million people worldwide. The bioavailability enhancement was based on the considerably improved dissolution. The release of a dose of 40 mg could be achieved within 15 min. Accordingly, administration of the nanofibrous system ensured an increased plasma concentration profile in rats in contrast to the practically non-absorbable crystalline flubendazole. Furthermore, easy-to-grind fibers could be developed, which enabled compression of easily administrable immediate release tablets.


Subject(s)
Mebendazole/analogs & derivatives , Nanofibers/chemistry , Povidone/chemistry , Tablets/chemistry , beta-Cyclodextrins/chemistry , 2-Hydroxypropyl-beta-cyclodextrin , Administration, Oral , Animals , Biological Availability , Chemistry, Pharmaceutical , Crystallization , Mebendazole/administration & dosage , Mebendazole/chemistry , Rats
14.
J Pharm Sci ; 106(6): 1634-1643, 2017 06.
Article in English | MEDLINE | ID: mdl-28257818

ABSTRACT

Novel, high-yield alternating current electrospinning (ACES) and direct current electrospinning methods were investigated to prepare high-quality hydroxypropylmethylcellulose acetate succinate (HPMCAS) fibers for the dissolution enhancement of poorly soluble spironolactone. Although HPMCAS is of great pharmaceutical importance as a carrier of marketed solid dispersion-based products, it was found to be unprocessable using electrospinning. Addition of small amounts of polyethylene oxide as aid polymer provided smooth fibers with direct current electrospinning but strongly beaded products with ACES. Solution characteristics were thus modified by introducing further excipients. In the presence of sodium dodecyl sulfate, high-quality, HPMCAS-based fibers were obtained even at higher throughput rates of ACES owing to the change in conductivity (rather than surface tension). Replacement of sodium dodecyl sulfate with non-surface-active salts (calcium chloride and ammonium acetate) maintained the fine quality of nanofibers, confirming the importance of conductivity in ACES process. The HPMCAS-based fibers contained spironolactone in an amorphous form according to differential scanning calorimetry and X-ray powder diffraction. In vitro dissolution tests revealed fast drug release rates depending on the salt used to adjust conductivity. The presented results signify that ACES can be a prospective process for high-scale production of fibrous solid dispersions in which conductivity of solution has a fundamental role.


Subject(s)
Drug Carriers/chemistry , Excipients/chemistry , Methylcellulose/analogs & derivatives , Nanofibers/chemistry , Drug Liberation , Methylcellulose/chemistry , Nanofibers/ultrastructure , Polyethylene Glycols/chemistry , Sodium Dodecyl Sulfate/chemistry , Solubility , Spironolactone/administration & dosage , Spironolactone/chemistry
15.
Ideggyogy Sz ; 70(5-6): 203-208, 2017 May 30.
Article in English | MEDLINE | ID: mdl-29870635

ABSTRACT

We present a case of MRI negative SMA seizure with the seizure onset zone in the secondary leg area on the superior bank of the Sylvian fissure, localized with multiscale electro-clinical and neuroradiological examinations. The 34-year-old female patient's intractable epilepsy started at age 14. She had diffuse pain aura in her left leg followed by tonic posturing with fully preserved consciousness suggesting parieto-fronto-medial seizure propagation. Her daily nocturnal SMA seizures became drug-resistant. Multiple 3T MRI images and neuropsychological evaluations were normal. Interictal PET detected a right parietal and insular FDG hypometabolism. The seizure onset zone and the symptomatogenic zone were localized by invasive electrophysiology. The insular deep electrode showed the propagation of ictal activity with an onset in the secondary sensory leg area through the insula to the fronto-medial surface. Eighteen spontaneous seizures, electrical cortical stimulation and cortical mapping confirmed the designated area of the resection, which was later proved macroscopically abnormal during surgery. The histological and immunohistological workup confirmed focal cortical dysplasia (IIb type). Postoperative postprocessing morphometry of the preoperative MRI study confirmed the lesion in the right inferior parietal lobe. The patient remained seizure free after surgery for more than 4 years, and medication free for the last two years. Our results concluded that the insula has a "relay" or "node" function in the parieto-opercular-fronto-medial epileptic network. The insular functional connectivity predisposed frontal propagation of the epileptic activity in the connectome of her epilepsy. The three-way insular structural connectivity has determining function on the seizure propagation.


Subject(s)
Cerebral Cortex/physiopathology , Cerebral Cortex/surgery , Drug Resistant Epilepsy/physiopathology , Drug Resistant Epilepsy/surgery , Adult , Cerebral Cortex/pathology , Drug Resistant Epilepsy/pathology , Female , Humans , Malformations of Cortical Development/pathology , Malformations of Cortical Development/physiopathology , Malformations of Cortical Development/surgery , Neural Pathways/pathology , Neural Pathways/physiopathology , Neural Pathways/surgery
16.
Mol Pharm ; 13(11): 3816-3826, 2016 11 07.
Article in English | MEDLINE | ID: mdl-27611057

ABSTRACT

The aim of this study was to investigate the impact of formulation excipients and solubilizing additives on dissolution, supersaturation, and membrane transport of an active pharmaceutical ingredient (API). When a poorly water-soluble API is formulated to enhance its dissolution, additives, such as surfactants, polymers, and cyclodextrins, have an effect not only on dissolution profile but also on the measured physicochemical properties (solubility, pKa, permeability) of the drug while the excipient is present, therefore also affecting the driving force of membrane transport. Meloxicam, a nonsteroidal anti-inflammatory drug, was chosen as a poorly water-soluble model drug and formulated in order to enhance its dissolution using solvent-based electrospinning. Three polyvinylpyrrolidone (PVP) derivatives (K30, K90, and VA 64), Soluplus, and (2-hydroxypropyl)-ß-cyclodextrin were used to create five different amorphous solid dispersions of meloxicam. Through experimental design, the various formulation additives that could influence the characteristics of dissolution and permeation through artificial membrane were observed by carrying out a simultaneous dissolution-permeation study with a side-by-side diffusion cell, µFLUX. Although the dissolution profiles of the formulations were found to be very similar, in the case of Soluplus containing formulation the flux was superior, showing that the driving force of membrane transport cannot be simplified to the concentration gradient. Supersaturation gradient, the difference in degree of supersaturation (defined as the ratio of dissolved amount of the drug to its thermodynamic solubility) between the donor and acceptor side, was found to be the driving force of membrane transport. It was mathematically derived from Fick's first law, and experimentally proved to be universal on several meloxicam containing ASDs and DMSO stock solution.


Subject(s)
Models, Theoretical , Polymers/chemistry , Solutions/chemistry , Dimethyl Sulfoxide/chemistry , Meloxicam , Molecular Structure , Nanofibers/chemistry , Polyethylene Glycols/chemistry , Polyvinyls/chemistry , Povidone/chemistry , Thiazines/chemistry , Thiazoles/chemistry , beta-Cyclodextrins/chemistry
17.
J Immunol Methods ; 438: 26-34, 2016 11.
Article in English | MEDLINE | ID: mdl-27568282

ABSTRACT

Monoclonal antibody and recombinant protein production benefits greatly from bovine serum as an additive. The caveat is that bovine serum IgG, co-purifies with mAbs and IgG Fc-containing fusion proteins and it presents a contaminant in the end products. In order to analytically validate the products, species specific reagents are needed that react with bovine IgG exclusively. Our attempts to find such commercially available reagents failed. Here, we report the production of species specific mAbs which recognize bovine IgG even in the presence of excess amount of mouse IgG. We present five mAbs: Bsi4028, Bsi4032, Bsi4033, Bsi4034 and Bsi4035 suitable to determine the presence of bovine IgG contamination via ELISA or immunoblotting in bioreactor derived mouse mAb preparations. To quantitate bovine IgG content we developed sensitive sandwich ELISAs capable to detect bovine IgG contaminant in the ng/ml (~10-11M/l) range. Finally, we show that bovine IgG is efficiently removed from bioreactor produced mouse mAb preparation via affinity depletion columns prepared with Bsi4028, Bsi4032, Bsi4033, Bsi4034, Bsi4035 mAbs.


Subject(s)
Antibodies, Monoclonal, Murine-Derived/analysis , Enzyme-Linked Immunosorbent Assay/methods , Hybridomas/immunology , Immunoglobulin G/analysis , Recombinant Proteins/analysis , Animals , Bioreactors , Cattle , Cross Reactions , Epitopes/immunology , Female , Immunoblotting , Mice , Mice, Inbred BALB C , Species Specificity
18.
J Pharm Biomed Anal ; 128: 236-246, 2016 Sep 05.
Article in English | MEDLINE | ID: mdl-27281579

ABSTRACT

This work demonstrates how nonlinearity in Raman spectrometry of pharmaceuticals can be handled and accurate quantification can be achieved by applying certain chemometric methods including variable selection. Such approach proved to be successful even if the component spectra are very similar or spectral intensities of the constituents are strongly different. The relevant examples are: blends of two crystalline forms of carvedilol ("CRYST-PM" blend) and a three-component pharmaceutical model system ("PHARM-TM" blend). The widely used classical least squares regression (CLS) and partial least squares regression (PLS) quantification methods provided relatively poor root mean squared error of prediction (RMSEP) values: approximately 2-4% and 4-10% for CRYST-PM and PHARM-TM respectively. The residual plots of these models indicated the nonlinearity of the preprocessed data sets. More accurate quantitative results could be achieved with properly applied variable selection methods. It was observed that variable selection methods discarded the most intensive bands while less intensive ones were retained as the most informative spectral ranges. As a result not only the accuracy of concentration determination was enhanced, but the linearity of models was improved as well. This indicated that nonlinearity occurred especially at the intensive spectral bands. Other methods developed for handling nonlinearity were also capable of adapting to the spectral nature of both data sets. The RMSEP could be decreased this way to 1% in CRYST-PM and 3-6% in PHARM-TM. Raman maps with accurate real concentrations could be prepared this way. All quantitative models were compared by the non-parametric sum of ranking differences (SRD) method, which also proved that models based on variable selection or nonlinear methods provide better quantification.


Subject(s)
Pharmaceutical Preparations/analysis , Spectrum Analysis, Raman/methods , Calibration , Carbazoles/chemistry , Carvedilol , Drug Combinations , Least-Squares Analysis , Nonlinear Dynamics , Propanolamines/chemistry , Reference Standards , Tablets
19.
J Pharm Sci ; 105(9): 2982-2988, 2016 09.
Article in English | MEDLINE | ID: mdl-27290626

ABSTRACT

Investigation of downstream processing of nanofibrous amorphous solid dispersions to generate tablet formulation is in a quite early phase. Development of high speed electrospinning opened up the possibility to study tableting of electrospun solid dispersions (containing polyvinylpyrrolidone-vinyl acetate and itraconazole [ITR] in this case). This work was conducted to investigate the influence of excipients on dissolution properties and the feasibility of scaled-up rotary press tableting. The dissolution rates from tablets proved to be mainly composition dependent. Magnesium stearate acted as a nucleation promoting agent (providing an active hydrophobic environment for crystallization of ITR) hindering the total dissolution of ITR. This crystallization process proved to be temperature dependent as well. However, the extent of dissolution of more than 95% was realizable when a less hydrophobic lubricant, sodium stearyl fumarate (soluble in the medium), was applied. Magnesium stearate induced crystallization even if it was put in the dissolution medium next to proper tablets. After optimization of the composition, scaled-up tableting on a rotary press was carried out. Appropriate dissolution of ITR from tablets was maintained for 3 months at 25°C/60% relative humidity. HPLC measurements confirmed that ITR was chemically stable both in the course of downstream processing and storage.


Subject(s)
Antifungal Agents/chemistry , Itraconazole/chemistry , Lubricants/chemistry , Antifungal Agents/administration & dosage , Chemistry, Pharmaceutical , Crystallization , Drug Compounding , Excipients , Itraconazole/administration & dosage , Solubility , Spectrum Analysis, Raman , Stearic Acids/chemistry , Tablets
20.
Ideggyogy Sz ; 69(1-2): 55-65, 2016 Jan 30.
Article in Hungarian | MEDLINE | ID: mdl-26987241

ABSTRACT

STUDY OBJECTIVES: The developing of diagnostical examinations in epileptology provides new challenges in seizure semiology. On the analysis of seizures it is important to examine the mechanisms of their propagation. The brain connectivity (based on the neuroimaging), the shadowing of the movement of excessive neuronal activity (based on computerized EEG and MEG methods), the cognition of the physiological and pathological brain networks are the footstone of the epileptic seizure propagation. The investigators prove, by means of case demonstrations of the role of the network nodes and the role of the epileptic hubs in the seizure symptomatology. METHODS: The preoperative, intra and postoperative data are analised of three insular and one parietal epileptic patients in point of view of their seizure symptomes. Complex neuroimaging, noninvasive and invasive electrophysiology, intensive long-term video-EEG monitoring, computerized EEG analysis, fuctional mapping, intraoperative corticography were used. The etiology were confirmed with hystology. RESULTS: It is observed that on seizure semiology our patients plays the insula a double role. In some cases, it is the focus of insular seizures with their symptoms difficult to identify. However, in the majority of cases and as a consequence of its rich neural connections, the insula has a peculiar property in the evolution of the symptomatogenic features of seizures. This observations are developing new relationships between the mechanism of seizure propagation and its semiological consequences. CONCLUSIONS: On epileptological point of view there are brain structures which has peculiar role in the "designe" of propagation of the epileptic excitement. The numerous new methods in neuroimaging and neurophysiology allowed the connectomical examination of the epileptic networks. The role of the epileptic diathesis is approachable with the metholdology of the brain connectivity. Theoretically the node of the epileptic network consist of the potential pathes where the localised excessive excitement can propagete. The route where the actual seizure can go adhead is determined by the actual edpileptic propensity of the above mentioned potential pathes.


Subject(s)
Cerebral Cortex/pathology , Cerebral Cortex/physiopathology , Epilepsies, Partial/diagnosis , Epilepsy/pathology , Epilepsy/physiopathology , Neuroimaging , Adult , Electroencephalography , Epilepsies, Partial/pathology , Epilepsies, Partial/physiopathology , Epilepsy/diagnostic imaging , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neuroimaging/methods , Tomography, Emission-Computed, Single-Photon , Video Recording
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