Performance of equity mutual funds in Thailand

This dissertation examines the performance of 242 open-ended equity mutual funds in Thailand from January 2009 to December 2017 by employing the Jensen’s measure, the Fama-French’s Three-factor model, and the Carhart’s Four-factor model. The overall results show that market risk premium, firm size, and momentum factors can largely explain the time-series variation in equity fund returns, and the Carhart’s Four-factor model is the most effective among all models. Using the net returns of these funds, the results of a value-weighted portfolio under the Carhart’s Four-factor model suggest that, on average, they outperform the market benchmark by 1.92% p.a. with a slightly lower systematic risk. Besides, evidence from individual fund analysis shows that 72 of out of these 242 funds can successfully beat the market. In addition, this study documents the small market timing skill of fund managers under the Treynor and Mazuy model. This indicates that the funds may have superior returns mainly because they follow the momentum trading strategy of buying past winner stocks and selling past loser stocks. Another reason may be due to the capability of fund managers to frequently outguess the market correctly. Apart from the performance analysis, this study investigates whether or not Thai equity funds exhibit persistence in performance. The results suggest that performance persistence does not exist because of last year’s bottom-performing funds, which possess a significantly positive timing ability and thus, overcome the past winners in the following year. Moreover, fund managers of last year’s top- performing funds may not rebalance their portfolio much so merely by chance they still hold good stocks in the following year. However, persistence does not last long since this return anomaly is eliminated once the market realises it. As a result, they are no longer at the top position in a year later

DEVELOPMENT, CHARACTERIZATION AND SKIN IRRITATION OF MANGOSTEEN PEEL EXTRACT SOLID DISPERSION CONTAINING CLAY FACIAL MASK

Objective: To develop a clay facial mask containing mangosteen peel extract solid dispersion (MPESD) for enhancing α-mangostin bioavailability and to determine suitable clay-based facial mask.Methods: The MPESD were prepared by a melting-solvent method employing PVP K30 and poloxamer 188 as a carrier. The water solubility was determined by HPLC method. The in vitro skin permeability was examined using porcine ear epidermis. The effects of clay types on the physical stability of MPESD and α-mangostin adsorption capacity were evaluated. The skin irritation was determined by 4 h human patch test.Results: After dissolved optimal formulation of MPESD in water, the spherical micelle was observed with a mean size of ~150 nm and showed significantly α-mangostin water solubility enhancement of ~7 mg/ml, 700 times greater than MPE. Upon mixing the MPESD with clays, a dry powder was obtained. In vitro permeation studies of the MPESD mixed with titanium dioxide showed lowest α-mangostin permeation, while MPESD mixed with mica or talcum showed similar permeation profile as free MPESD solutions. No sign of skin irritation was observed in volunteers after application of the MPESD-based clay facial mask patch on the inner forearm skin for 4 h.Conclusion: MPESD demonstrates a promising technique for improving water solubility and permeation of α-mangostin which reducing the staining effect. In addition, it is safe for topical application and cosmetically acceptable

A laminated polymer film formulation for enteric delivery of live vaccine and probiotic bacteria

Live bacterial cells (LBC) are administered orally as attenuated vaccines, to deliver biopharmaceutical agents, and as probiotics to improve gastrointestinal health. However, LBC present unique formulation challenges and must survive gastrointestinal antimicrobial defenses including gastric acid after administration. We present a simple new formulation concept, termed Polymer Film Laminate (PFL). LBC are ambient dried onto cast acid-resistant enteric polymer films that are then laminated together to produce a solid oral dosage form. LBC of a model live bacterial vaccine and a probiotic were dried directly onto a cast film of enteric polymer. The effectiveness at protecting dried cells in a simulated gastric fluid (pH 2.0) depended on the composition of enteric polymer film used, with a blend of ethylcellulose plus Eudragit L100 55 providing greater protection from acid than Eudragit alone. However, although PFL made from blended polymers films completely released low molecular weight dye into intestinal conditions (pH 7.0), they failed to release LBC. In contrast, PFL made from Eudragit alone successfully protected dried probiotic or vaccine LBC from simulated gastric fluid for 2h, and subsequently released all viable cells within 60min of transfer into simulated intestinal fluid. Release kinetics could be controlled by modifying the lamination method

Performance of equity mutual funds in Thailand

This dissertation examines the performance of 242 open-ended equity mutual funds in Thailand from January 2009 to December 2017 by employing the Jensen’s measure, the Fama-French’s Three-factor model, and the Carhart’s Four-factor model. The overall results show that market risk premium, firm size, and momentum factors can largely explain the time-series variation in equity fund returns, and the Carhart’s Four-factor model is the most effective among all models. Using the net returns of these funds, the results of a value-weighted portfolio under the Carhart’s Four-factor model suggest that, on average, they outperform the market benchmark by 1.92% p.a. with a slightly lower systematic risk. Besides, evidence from individual fund analysis shows that 72 of out of these 242 funds can successfully beat the market. In addition, this study documents the small market timing skill of fund managers under the Treynor and Mazuy model. This indicates that the funds may have superior returns mainly because they follow the momentum trading strategy of buying past winner stocks and selling past loser stocks. Another reason may be due to the capability of fund managers to frequently outguess the market correctly. Apart from the performance analysis, this study investigates whether or not Thai equity funds exhibit persistence in performance. The results suggest that performance persistence does not exist because of last year’s bottom-performing funds, which possess a significantly positive timing ability and thus, overcome the past winners in the following year. Moreover, fund managers of last year’s top- performing funds may not rebalance their portfolio much so merely by chance they still hold good stocks in the following year. However, persistence does not last long since this return anomaly is eliminated once the market realises it. As a result, they are no longer at the top position in a year later

Neue Formulierungs- und Verarbeitungsaspekte für Manteltabletten und für die Kompression von Polymer-überzogenen Multiparticulates

To achieve compression of polymer-coated pellets into tablets, good flexibility of the polymeric coating is crucial in order not to rupture and to loose the modified release properties. Enteric polymers are quite brittle in the dry state and thus not suitable as pellet coatings for compression into tablets. The objective of this study was to investigate the role of humidity treatment prior to compression and thus the role of moisture as potent plasticizer for the successful compression of enterically coated pellets. Eudragit L30D-55 coated pellets were stored at different humidities for different time periods and then compressed and evaluated for changes in acetaminophen release. The damage to the Eudragit L-coated pellets decreased with increasing storage humidity and storage time, as indicated by a lower increase in release upon compression. A higher storage humidity resulted in an increased water content and plasticization effect of the films as indicated by a decrease in the glass transition temperature of films. Second, pH-erosion controlled compression-coated tablets for potential colonic drug delivery with improved gastric resistance and pulsatile release based on compression- coatings of powder blends of the enteric polymer Eudragit L 100-55 and ethylcellulose (EC) were studied. Tablet cores containing model drugs (acetaminophen, carbamazepine, propranolol HCl and chlorpheniramine maleate) were compression-coated with different ratios of Eudragit L100-55: EC at different compression forces and tablet core:coat ratios. Pulsatile drug release in higher pH-media after a lag time, which was controlled by the erosion of the Eudragit L: EC compression-coating. The addition of EC avoided premature drug release in lower pH-media and significantly increased the lag time in higher pH-media because of a reduction in wettability, media uptake and erosion of the compression-coatings. Third, flexible extended drug release profiles with hydroxypropyl methylcellulose (HPMC) compression-coated tablets could be obtained. The HPMC-compression-coating resulted in release profiles with a distinct lag time followed by different release phases primarily determined by the drug solubility. Carbamazepine, a water-insoluble drug, was released in a pulsatile fashion after erosion of the HPMC compression-coat, while the more soluble drugs were released in a sigmoidal fashion by diffusion through the gel prior to erosion. With carbamazepine, increasing the molecular weight of HPMC significantly increased the lag time because of the erosion- based release mechanism, while, in contrast, molecular weight did not affect the release of the more soluble drugs. The lag-time and the release rate could also be well controlled by varying the HPMC amount in and the thickness of the compression-coating. A pulsatile release could be achieved for water-soluble drugs by introducing an enteric polymer coating between the drug core and the HPMC compression-coating to eliminate drug diffusion through the gelled HPMC layer prior to its erosion. The lag time increased with increasing Eudragit L coating because of a slower dissolution of the thicker coating. Pulsatile release was obtained with the lower molecular weight HPMC E50 and 400, but extended release with longer lag time with from HPMC K4M. Incorporating drug in the compression-coating and tablet core in varying ratios resulted in release profiles with increasing, decreasing or constant release rates.Zur Tablettierung von filmüberzogenen Pellets eine gute Flexibilität des Polymerüberzüge entscheidend um Risse im Film zu vermeiden und dementsprechend die Freisetzungseigenschaften nicht zu verändern. Magensaftresistente Polymere sind sehr spröde in trockenem Zustand und sind daher als Filmüberzüge für Pellets zur Verpressung in Tabletten nicht geeignet. Das Ziel dieser Studie war es Feuchtigkeit als potenten Weichmacher zu untersuchen um magensaftresistent überzogene Pellets erfolgreich zu verpressen. Eudragit L30D-55 überzogene Pellets mit dem Wirkstoff Acetaminophen wurden bei verschiedenen Luftfeuchten für unterschiedliche Zeiträume gelagert und zu Tabletten verpresst. Anschließend wurden mögliche Veränderungen des Freisetzungsverhaltens bestimmt. Die Beschädigung der Eudragit® L haltigen Filme verringerte sich mit ansteigender Lagerungsfeuchtigkeit und ansteigender Lagerungszeit was durch eine langsamere Freisetzung angezeigt wurde. Die Lagerung bei höherer Luftfeuchtigkeit führte zu einem erhöhten Wassergehalt in den Filmen welcher zu einer verbesserten Plastifizierung führte. Das zweite Ziel dieser Studie war es, Manteltabletten mit verbesserter Magensaftresistenz zur potentiellen Arzneistoffapplikation im Dickdarm zu entwickeln, basierend auf Polymerpulver-Mischungen aus magensaftresistentem Eudragit L 100-55 und retardierender, wasserunlöslicher Ethylcellulose. Die pulsatile Freisetzung dieser Tabletten sollte durch pH-Wert und Erosion kontrolliert werden. Die Tablettenkerne mit Modell-Arzneistoffen unterschiedlicher Löslichkeiten (Paracetamol, Carbamazepin und Chlorpheniraminmaleat) wurden mit Mischungen der beiden Polymere ummantelt; dabei wurden das Polymer-Verhältnis von Eudragit L100-55 zu Ethylcellulose 10cp FP, von Tablettenkern zum Mantel sowie die Pressdrücke variiert. Der Zusatz von Ethylcellulose verhinderte eine vorzeitige Wirkstofffreisetzung bei niedrigeren pH-Werten und erhöhte bei höheren pH-Werten signifikant die lag-Zeit aufgrund verringerter Benetzbarkeit, Flüssigkeitsaufnahme und Erosion des Mantels. Das dritte Ziel dieser Studie war es, flexibel steuerbare Freisetzungsprofile für Wirkstoffe (z.Bsp. sigmoidal, pulsatil, hohe / niedrige Freisetzungsraten) mit Hydroxypropylmethylcellulose (HPMC) Manteltabletten zu erhalten. Der HPMC- Mantel führte zu Freisetzungen mit einer deutlichen lag-Zeit gefolgt von verschiedenen Freisetzungsphasen, welche in erster Linie durch die Arzneistofflöslichkeit bestimmt wurden. Carbamazepin, ein schwer löslicher Arzneistoff, wurde erst nach vollständiger Erosion des HPMC-Mantels pulsatil freigesetzt, während die besser löslichen Arzneistoffe schon vorher durch Diffusion durch das Gel und somit eher sigmoidal freigesetzt wurden. Aufgrund des erosions-basierten Freisetzungsmechanismus konnte für Carbamazepin auch festgestellt werden, dass eine Erhöhung des Molekülgewichts der HPMC die lag- Zeit signifikant verlängerte, während im Gegensatz dazu das Molekülgewicht keine Auswirkungen auf die Freisetzung der besser löslichen Substanzen zeigte. Die Lag-Zeit und die Freisetzungsrate konnten durch den HPMC-Anteil und die Schichtdicke des Mantels gut gesteuert werden. Eine pulsatile Freisetzung konnte auch für wasserlösliche Arzneistoffe erreicht werden durch die Einführung einer magensaftresistenten Polymerschicht zwischen dem Tablettenkern und dem HPMC-Mantel. Mit zunehmender Schichtdicke von Eudragit L verlängerte sich die lag-Zeit aufgrund der langsameren Auflösung der Eudragit- Schicht. Mit den niedrigeren Molekulargewichten HPMC E50 und 400 wurde pulsatile Freisetzung erhalten, während HPMC K4M zu retardierter Freisetzung und längeren lag-Zeiten führte. Eine zusätzliche Einbettung von Arzneistoffen in den Mantel in unterschiedlichen Anteilen führte zu Profilen mit zunehmenden, abnehmenden oder konstante Freisetzungsraten

Accuracy of methods for diagnosing heart diseases in cats

Aim: This study aimed to determine the accuracy of the current methods for diagnosing heart diseases in cats. Materials and Methods: The data of 58 cats were retrospectively retrieved. Cats were classified into two groups: Thirty-eight cats with heart diseases and 20 healthy cats. Echocardiography was the gold standard method for diagnosing heart disease. The results of seven methods were retrieved: (1) Vertebral heart score (VHS) with a cutoff value >8, (2) VHS with a cutoff value >8.5, (3) multiplication of cardiac length (L) and width (W), (4) multiplication of cardiac L and W divided by the L of the fourth sternal thoracic bone, (5) N-terminal Pro-B-type natriuretic peptide (NT-proBNP) point-of-care test, (6) subjective ultrasonographic assessment of the left atrial size, and (7) subjective radiographic assessment of the left atrial size. Cross-tabulation was used to calculate the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for each test. This study found that using the NT-proBNP point-of-care test was optimal in the diagnosis of cats with heart disease. Results: The subjective ultrasonographic assessment of the left atrial size was good for diagnosing hypertrophic cardiomyopathy and congestive heart failure. Conclusion: This study showed that the more tests used, the higher the reliability of the diagnosis