The First Enantioselective Total Synthesis of (-)-trans-Dihydronarciclasine.

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.

Oral bioavailability enhancement of flubendazole by developing nanofibrous solid dosage forms.

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.

The role of the insula in the parieto-frontomedial epileptic network. Clues from successful surgical treatment.

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.

Investigation and Mathematical Description of the Real Driving Force of Passive Transport of Drug Molecules from Supersaturated Solutions.

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.

[THE PROPAGATION AND SEMIOLOGY OF FOCAL EPILEPTIC SEIZURES. CASES CONNECTED TO THE INSULA. THEORETICAL CONSIDERATIONS]. / A FOKÁLIS EPILEPSZIÁS ROHAMOK TERJEDÉSE ÉS SZEMIOLOGIÁJA. INSULÁHOZ KAPCSOLÓDÓ BETEGTANULMÁNYOK. ELMÉLETI MEGGONDOLÁSOK.

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.

Role of modified open-door laminoplasty in the treatment of multilevel cervical spinal stenosis: a retrospective analysis of 43 cases.

BACKGROUND AND PURPOSE: Symptomatic degenerative multilevel cervical spinal stenosis--beside other methods--is often treated using the open-door laminoplasty. This procedure aims to decompress the spinal cord and preserve the stability of the cervical spine. The efficiency and safety of the method was proved by numerous Japanese and American studies, also the technique related complications are well known. We treated 43 patients with symptomatic multilevel cervical spine stenosis using the open-door laminoplasty as a surgical procedure of choice in the National Institute of Clinical Neurosciences between 2009 and 2012. In this article we analyse our results and the related literature is discussed. METHODS: Symptomatic patients with a minimum of three-segment cervical spine stenosis and radiologically proved myelopathy or with electrophisiologically verified subclinical myelopathy were selected for laminoplasty. Patients in whom cervical kyphosis was present were operated on using laminectomy and posterior fusion. Postoperative control CT, MRI and/or X-ray images were made after the surgery and at six weeks, three, six and 12 months after the operation and in the same time neurological evaluation was performed. The modified Japanase Orthopaedic Association (mJOA) scale value was assigned to patients preoperatively, six weeks, three, six and 12 months after the operation. The statistical difference between the groups of data was tested by chi square test. RESULTS: The average follow-up time was 27 months (minimum seven, maximum 42). According to the mJOA scale, 26 patient's condition (61%) improved, in 13 cases (30%) remained unchanged, and in one case (2%) we detected neurological deterioration. We lost three patients during the follow up period. The median of mJOA preoperatively was 12 (minimum eight, maximum 18), while six week postoperative mJOA was 14 (minimum 10, maximum 17). Three, six and 12 months mean value of mJOA was 14 which shows that the improvement in patients' condition remained stable at one year after surgery. The difference was statistically significant (p < 0.05). The canal's average anteroposterior diameter on CT was 8.29 ± 0.92 mm at the level of C III, while after the operation we measured 15.16 ± 1.02 mm; 7.54 ± 0.62 mm at the level of C IV before, and 15.29 ± 0.2 mm after; 9.05 ± 0.48 mm at the level of C V before and 17.23 ± 0.4 mm after the surgery. The differences proved to be significant (p = 0.0001). CONCLUSION: According to our experiences the modified open-door laminoplasty is an efficient and safe method for the treatment of symptomatic multilevel cervical spinal stenosis.

[Treatment of osteoporotic vertebral compression fractures with PMMA-augmented pedicle screw fixation]. / Osteoporoticus kompressziós csigolyatörések kezelése PMMA-augmentált csavaros transpedicularis rögzítéssel.

BACKGROUND: Over the last few decades many innovative operation technique were developed due to the increase of porotic vertebral fractures. These new techniques aim to reach the required stability of the vertebral column. In case of significant instability, spinal canal stenosis or neural compression, decompressive intervention may be necessary, which results in further weakening of the column of the spine, the minimal invasive percutan vertebroplasty is not an adequate method to reach the required stability, that is why insertion of complementary pedicular screws is needed. Considering the limited screw-fixing ability of the porotic bone structure, with this new technique we are able to reach the appropriate stability of cement-augmented pedicle screws by dosing cement carefully through the screws into the vertebral body. We used this technique in our Institute in case of 12 patients and followed up the required stability and the severity of complications. METHODS: Fifteen vertebral compression fractures of 12 patients were treated in our Institute. Using the classification proposed by Genant et al. we found that the severity of the vertebral compression was grade 3 in case of 13, while grade 2 in case of two fractures. The average follow up time of the patients was 22 months (12-39), during this period X-ray, CT and clinical control examinations were taken. During the surgery the involved segments were localised by using X-ray and after the exploration the canulated screws were put through the pedicles of the spine and the vertebral body was filled through the transpedicular screws with bone cement. Depending on the grade of the spinal canal stenosis, we made the decompression, vertebroplasty or corpectomy of the fractured vertebral body, and the replacement of the body. Finally the concerned segments were fixed by titanium rods. RESULTS: In all cases the stenosis of spinal canal was resolved and the bone cement injected into the corpus resulted in adequated stability of the spine. In case of six patients we observed cement extravasation without any clinical signs, and by one patient--as a serious complication--pulmonary embolism. Neurological progression or screw loosening were not detected during the follow up period. Part of the patients had residual disability after the surgery due to their older ages and the problem of their rehabilitation process. CONCLUSION: After the right consideration of indications, age, general health condition and the chance of successful rehabilitation, the technique appears to be safe for the patients. With the use of this surgical method, the stability of the spine can be improved compared to the preoperative condition, the spinal canal stenosis can be solved and the neural structures can be decompressed. The severity of complications can be reduced by a precise surgical technique and the careful use of the injected cement. The indication of the surgical method needs to be considered in the light of the expected outcome and the rehabilitation.

Multicapillary SDS-gel electrophoresis for the analysis of fluorescently labeled mAb preparations: a high throughput quality control process for the production of QuantiPlasma and PlasmaScan mAb libraries.

Molecular heterogeneity of mAb preparations is the result of various co- and post-translational modifications and to contaminants related to the production process. Changes in molecular composition results in alterations of functional performance, therefore quality control and validation of therapeutic or diagnostic protein products is essential. A special case is the consistent production of mAb libraries (QuantiPlasma™ and PlasmaScan™) for proteome profiling, quality control of which represents a challenge because of high number of mAbs (>1000). Here, we devise a generally applicable multicapillary SDS-gel electrophoresis process for the analysis of fluorescently labeled mAb preparations for the high throughput quality control of mAbs of the QuantiPlasma™ and PlasmaScan™ libraries.

[The interactive neuroanatomical simulation and practical application of frontotemporal transsylvian exposure in neurosurgery]. / A frontotemporalis transsylvian feltárás szimulációja és alkalmazásának ismertetése.

BACKGROUND AND PURPOSE: There is an increased need for new digital education tools in neurosurgical training. Illustrated textbooks offer anatomic and technical reference but do not substitute hands-on experience provided by surgery or cadaver dissection. Due to limited availability of cadaver dissections the need for development of simulation tools has been augmented. We explored simulation technology for producing virtual reality-like reconstructions of simulated surgical approaches on cadaver. Practical application of the simulation tool has been presented through frontotemporal transsylvian exposure. METHODS: The dissections were performed on two cadaveric heads. Arteries and veins were prepared and injected with colorful silicon rubber. The heads were rigidly fixed in Mayfield headholder. A robotic microscope with two digital cameras in inverted cone method of image acquisition was used to capture images around a pivot point in several phases of dissections. Multilayered, high-resolution images have been built into interactive 4D environment by custom developed software. RESULTS: We have developed the simulation module of the frontotemporal transsylvian approach. The virtual specimens can be rotated or tilted to any selected angles and examined from different surgical perspectives at any stage of dissections. Important surgical issues such as appropriate head positioning or surgical maneuvers to expose deep situated neuroanatomic structures can be simulated and studied by using the module. CONCLUSION: The simulation module of the frontotemporal transsylvian exposure helps to examine effect of head positioning on the visibility of deep situated neuroanatomic structures and study surgical maneuvers required to achieve optimal exposure of deep situated anatomic structures. The simulation program is a powerful tool to study issues of preoperative planning and well suited for neurosurgical training.

Insider trading.

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.

Fractionation of the human plasma proteome for monoclonal antibody proteomics-based biomarker discovery.

mAb proteomics, a reversed biomarker discovery approach, is a novel methodology to recognize the proteins of biomarker potential, but requires subsequent antigen identification steps. While in case of high-abundant proteins, it generally does not represent a problem, for medium or lower abundant proteins, the identification step requires a large amount of sample to assure the proper amount of antigen for the ID process. In this article, we report on the use of combined chromatographic and precipitation techniques to generate a large set of fractions representing the human plasma proteome, referred to as the Analyte Library, with the goal to use the relevant library fractions for antigen identification in conjunction with mAb proteomics. Starting from 500 mL normal pooled human plasma, this process resulted in 783 fractions with the average protein concentration of 1 mg/mL. First, the serum albumin and immunoglobulins were depleted followed by prefractionation by ammonium sulfate precipitation steps. Each precipitate was then separated by size exclusion chromatography, followed by cation and anion exchange chromatography. The 20 most concentrated ion exchange chromatography fractions were further separated by hydrophobic interaction chromatography. All chromatography and precipitation steps were carefully designed aiming to maintain the native forms of the intact proteins throughout the fractionation process. The separation route of vitamin D-binding protein (an antibody proteomics lead) was followed in all major fractionation levels by dot blot assay in order to identify the library fraction it accumulated in and the identity of the antigen was verified by Western blot.

Whole genome transcriptional profiling identifies novel differentiation regulated genes in keratinocytes.

Keratinocyte differentiation plays a pivotal role in the epidermal barrier. Single keratinocyte differentiation genes have already been studied, but many important constituents of this process may have been missed so far. Gene expression profiling by microarray was carried out in cultured normal human epidermal keratinocytes undergoing confluence-induced differentiation to find novel differentiation genes. Candidate gene lists were established and genes of potential dermatological interest were validated by quantitative reverse transcription polymerase chain reaction and immunohistochemical analysis. Some of these points lead to the identification of counter-regulation of heme oxygenase and biliverdin reductase as well as glutaredoxin and glutathione reductase indicative of potential novel redox signaling in differentiating human keratinocytes. Others indicate a strong concert down-regulation of interleukin-1 signaling at previously unidentified levels during keratinocyte differentiation. We believe that identified genes contribute to a more comprehensive understanding of the complicated epidermal differentiation process and lead to better understanding of dermatological diseases.

[Multicenter observational study of the effect of oxcarbazepine on the general well-being of adults with partial epilepsy]. / Többcentrumos, megfigyeléses vizsgálat az oxcarbazepin hatásáról a parciális epilepsziás felnott betegek általános közérzetére.

AIMS: An open label, national, multicenter, observational study had been conducted to evaluate of psychological general well-being in adults with therapy resistant partial epilepsy taking oxcarbazepine in Hungary. The possibility was examined to differentiate the improvement of the psychic well-being caused by the better status of the seizure disorder or caused by the psychopharmacological effect of the oxcarbazepine (in the next: OXC). METHODS: 528 patients were asked to fill the Hungarian validated version of Psychological General Well-Being Schedule (PGWB), English version created by Harold J. Dupuy in 1984, at the baseline visit and after 12- week long duration OXC therapy regim. Finally the data of 332 patients could be evaluated per protocol, biostatistical analysis was carried out. RESULTS: Based on data of 332 patients (per protocol population) the OXC treatment significantly (p < 0.0001) improved all items of PGWB in clinically well-controlled (responder) epileptic patients and improved affective markers of patients with uncontrolled epilepsy also. In case of patients suffering from uncontrolled epilepsy the increase of psychical wellbeing items score influenced by biological effects were higher than those influenced by external effects. CONCLUSIONS: It can be stated that the adopted PGWB test battery is reliable quantitative method to examine the psychological well-being of patients suffering from partial epilepsy. It was observed that OXC has significant psychopharmalogical effect besides the well-known anticonvulsive property among large Hungarian population of partial epileptic patiens. In case of OXC therapy the positive psychic effect of the successful anticonvulsive treatment and the stabilization property on the affectivity of epileptic patients significantly separates. The OXC has no indication for the treatment of psychiatric conditions.

Frequency and waveform dependence of alternating current electrospinning and their uses for drug dissolution enhancement.

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.

End-to-end continuous manufacturing of conventional compressed tablets: From flow synthesis to tableting through integrated crystallization and filtration.

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.

Neuronavigation and fluoroscopy-assisted subdural strip electrode positioning: a simple method to increase intraoperative accuracy of strip localization in epilepsy surgery.

For localization of the epileptogenic zone in cases of focal epilepsy, detailed clinical investigations, imaging studies, and electrophysiological methods are used. If the noninvasive presurgical evaluation provides insufficient data, intracranial electrodes are necessary. Computed tomography and MR imaging techniques are the gold standard for localization of the postoperative position of the implanted intracranial electrode contacts. If the electrode strips are inserted through a bur hole, however, the exact localization of the electrode contacts on the patient's brain remains uncertain for the surgeon during insertion. Therefore, the authors developed a simple method to visualize the electrodes during the procedure. In this method they combine neuronavigation and intraoperative fluoroscopy for parallel visualization of the cortex, electrodes, and the navigation probe. The target region is searched with neuronavigation, a bur hole is made over the optimal entry point, and using real-time fluoroscopy the strip electrode is slid to the tip of the navigation probe, which was kept over the area of interest. At the authors' institution 26 strips in 8 patients have been inserted with this technique, and none of the strips had to be repositioned. There were no complications with this procedure and the prolongation of surgery time is acceptable. Compared to previously published electrode placement methods, this one enhances the accuracy of electrode placement at occipital, parietal, frontal, or interhemispheric regions as well. Intraoperative visualization of the electrodes with fluoroscopy combined with neuronavigation during positioning through a bur hole gives the neurosurgeon the ability to control the real position of the electrode over the gyri during the procedure.

Interhemispheric propagation of seizures in mesial temporal lobe epilepsy.

OBJECTIVES: To investigate interhemispheric propagation of mesial temporal lobe epilepsy seizures in patients undergoing long-term video-EEG monitoring with combined scalp and foramen ovale electrodes. AIM OF THE STUDY: To reveal possible interhemispheric propagation patterns in mesial temporal lobe epilepsy, to improve presurgical evaluation of temporal epileptic patients. METHODS: Sixty-five seizures from 20 patients were analyzed. We defined two contralateral seizure propagation patterns: Type I for those seizures that spread to the contralateral foramen ovale electrodes earlier than to the contralateral scalp electrodes, and type II for the opposite. PARTICIPANTS: Twenty drug resistant epileptic patients were investigated in frame of their presurgical evaluation. RESULTS: The majority of seizures (80%) were classified as type I. Inter-foramen ovale electrode propagation time was significantly shorter for type I compared to type II seizures. Ninety percent of patients had either type I or type II seizures only. Patients with type I seizures significantly more often had mesiotemporal structural alterations evident on magnetic resonance imaging scans, and became more often seizure-free after surgery compared to patients with type II seizures whose surgical outcome was less favorable or surgery could not be indicated because of independent bilateral ictal seizure-onset. CONCLUSIONS: The two types of contralateral propagation patterns we are describing seem to represent two subtypes of mesial temporal lobe epilepsy with different morphological and prognostic features. The predominance of type I over type II seizures together with shorter propagation times for type I seizures indicate a role of a more direct and dominant interhemispheric pathway in mesial temporal lobe epilepsy.

Corona alternating current electrospinning: A combined approach for increasing the productivity of electrospinning.

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.

Continuous manufacturing of orally dissolving webs containing a poorly soluble drug via electrospinning.

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.

The applicability of pharmaceutical polymeric blends for the fused deposition modelling (FDM) 3D technique: Material considerations-printability-process modulation, with consecutive effects on in vitro release, stability and degradation.

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.