Key Engineering Materials Vol. 859

Abstract: Kaempferia parviflora rhizomes exposed to gamma irradiation at doses of 0, 5, and 7.5 kGy were evaluated every 3 months for their microbial loads, contents of 5,7-dimethoxyflavone (DMF), total phenolic contents, and antioxidant activities (DPPH and FRAP assays) during 12 months of storage at 25 °C. After gamma irradiation, microbial loads were reduced below acceptable limits. Phytochemical contents in irradiated samples were significantly increased as compared to those of the control (0 kGy) while DPPH radical scavenging activities were significantly decreased. However, gamma irradiation had no effect on FRAP values. During storage of irradiated samples, phytochemical contents and antioxidant activities were gradually decreased whereas microbial loads were progressively increased. Even so, microbial quality of irradiated samples was less than acceptable limits through 12 months' storage. Gamma irradiation at doses of 5 and 7.5 kGy was sufficient to control microbial growth and T. castaneum infestation of K. parviflora rhizomes within acceptable limits for at least 12 months at 25 °C. Additionally, 5 and 7.5 kGy were effective doses to retain DMF and phenolics in K. parviflora rhizomes.

Abstract: The objective of this study was to investigate the effects of thermal crosslinking on the properties of 3D-printed poly-vinyl alcohol (PVA) tablets loaded with fluorescein sodium (NaFl). The PVA filaments were selected for the fabrication of 3D-printed tablets. Different infill densities (80% and 100%) of the tablets were applied. The tablets were crosslinked at different temperatures and times. The physiochemical properties of the tablets and the release profiles of fluorescein from the 3D-tablets were investigated. The 3D-printed PVA tablets were successfully produced with favorable physical and mechanical properties. A smooth surface with a mesh pattern was obtained with a yellow color of NaFl. The 100% infilled tablets provided slightly greater loading efficiency and loading capacity in comparison with the 80% infilled tablets. The release of NaFl increased with an increase in crosslinking time and temperature. However, crosslinking at 140 °C for 4 h (80% CFT4 and 100%CFT4) showed similar release characteristic compared to the non-crosslink one. The release kinetics of 3D-printed tablets were observed to be Quasi-Fickian diffusion mechanism.

Abstract: Lactobacillus rhamnosus GG is commonly used as probiotic dietary supplements that show poor survival rate in dairy products during processing, storage and gastrointestinal tract, however, using encapsulated probiotics could be an interesting option. Spray drying is the most widely used encapsulation technique in the food industry. It offers the attractive advantage of microencapsulation in low operating costs, high quality and stability, rapid solubility and continuous operation. The encapsulating agent of microcapsules affects probiotic survival. The aim of this study was to optimize the microencapsulation of Lactobacillus rhamnosus GG (LGG) by spray drying using whey protein and glutinous rice starch as encapsulating agents. The composition ratio between glutinous rice starch and whey protein and spray drying parameter of inlet temperature was evaluated using response surface methodology (RSM). These results showed that 80 % of glutinous rice starch replacement in whey protein wall and inlet temperature of 143°C provided the desired LGG microcapsules with high percentage of process yield (over 74.44 ± 3.95%) and survival rate (over 97.83 ± 2.01%).

Abstract: Microencapsulation by spray drying is offered to prevent volatilization or degradation of lemongrass essential oil as food additives and ingredients in traditional medicines. In this process, oil is contained in microcapsules by enclosing with wall material. Although gum arabic is commonly used according to its encapsulation efficiency and stability, its cost is more expensive. This experiment used cassava starch for wall material because it was cheaper than gum and could get optimized condition for microencapsulation of lemongrass essential oil. The 3 factors of microcapsulation consisting of the mass ratio of CS:GA, mass ratio of wall: core materials, and inlet temperatures were optimized for maximum response, the process yield (PY) and encapsulation efficiency (EE) using response surface methodology. The results concluded that the highest weight replacement of cassava starch and gum arabic at 2.4:1, wall:core ratio 3.4-4.0:1 with inlet air temperature about 180 °C for spray drying was the optimal condition for was higher than 70 % PY and 85 % EE.

Abstract: UV-Vis spectrophotometric method was validated for the stability assessment of 5% extemporaneous vancomycin eye drops in different vehicles. The eye drops were extemporaneously prepared by dissolving vancomycin in various vehicles, including sterile water for injection (SWI), 0.45% normal saline (0.45%NSS) and artificial tear. The solutions were stored at room temperature and in refrigerator for 30 days. The content of vancomycin was measured by UV-Vis spectrophotometer at 280 nm. UV-Vis Spectrophotometric method was validated according to ICH guideline. The results indicated that the method was precise and accurate. The calibration curve was linear with r² = 0.9997 in the range of 40-160 μg/mL. LOD and LOQ were 3.39 and 10.26 μg/mL, respectively. The results showed that the percentage of vancomycin residual concentation in SWI and 0.45%NSS was decreased to less than 90% after storage at room temperature for 8 days, whereas the residual concentration of vancomycin in artificial tear was less than 90 % after 10 days in room temperature. Meanwhile the percentage of vancomycin residual concentation in all formulations was remarkably decreased to less than 90% after storage in refrigerator for 17 days. The physical appearance of eye drops in artificial tear remained unchanged. However the observed color of other formulations was gradually changed to yellow in day 7 at room temperature and day 17 in refrigerator. The pH values of all preparations were within the general U.S. pharmacopeia national formulation range of 2.5-4.5. In conclusion, the eye preparations of 5%w/v vancomycin in all selected vehicle were stable for 17 days in refrigerator (2-8°C).

Abstract: The purpose of this study was to examine the effect of processing parameters on drug release profiles of microparticles. Double emulsion solvent evaporation technique was utilized to encapsulate donepezil hydrochloride which is a hydrophilic drug. The processing parameters examined were polymer amount, stirring time and volume of external aqueous phase. The morphology of microparticles was observed under light microscope and scanning electron microscope. After that, in vitro drug release testing was conducted in simulated salivary fluid (pH6.75) and simulated gastric fluid (pH1.2). The results showed that these three parameters were the significant parameter affecting drug release profiles of the microparticles.

Abstract: Gastro-retentive drug delivery systems (GRDDS) have been developed with the aim of prolonging drug release. In this study, floating device systems (FDS) were developed and incorporated with a domperidone tablet (Motilium-M®). The FDSs were made of polyvinyl alcohol (PVA) using a fused deposition modelling (FDM) 3D-printer and crosslinked by thermal crosslinking process. The morphology, water insolubilization, water uptake, thermal analysis, FT-IR, floating time and drug release were investigated. The results showed that thermal crosslinking caused the structural change of PVA. Increasing the crosslinking time increased the crystallinity of the polymer resulted in the decreased water solubility, water uptake, and swelling property. An optimal crosslinking condition for the FDS was heating at 120 °C for 6 h. Floating time of the FDS decreased after the crosslinking process. However, the sustained drug release of domperidone from the FDSs were observed after the thermal crosslinking process.

Abstract: The world’s population is aging; therefore, conventional pharmaceutical dosage forms designed for adult are not suitable. Orally disintegrating tablets (ODTs) are innovative dosage forms designed to overcome the problem of difficulty in swallowing or dysphagia, which is a common problem among all age groups, especially the elderly. This study aimed to develop and assess ODTs loaded with astaxanthin and manufactured by direct compression method using different coprocessed pharmaceutical excipients, including F-Melt^® Type C, F-Melt^® Type M, and Pearlitol Flash^®. The results found that the ODTs prepared from F-Melt^® Type C and F-Melt^® Type M offered better mechanical properties. An astaxanthin concentration of 20–40 mg in the tablets did not retard the disintegration mechanism. From the taste modified formulation, the tablets disintegrated within 82 seconds. The tablet hardness was higher than 35.33 N and its friability was less than 0.5%. Lastly, active ingredient dissolved more than 80% in 2 minutes.

Abstract: Garlic exerts its pharmacological activities; antihyperglycemic, antihyperlipidemia, antihypercholesterolemic, and antihypertensive activity. Therefore, the aim of this study was to determine and optimize the influence of the individual and interactive effect of process conditions variables on the yield of garlic extract powders by three factors and three level-Box-Behnken design under response surface methodology. Spray drying processes the transformation of a garlic juice extract into a dried powder, where usually maltodextrin (MD) as a drying agent is used. According to experimental design, the mixing of garlic juice extract (85 – 95 %w/w) and MD (5 – 15 %w/w) were dried at an air inlet temperature 110°C - 150°C and liquid feed flow rate 5 – 35 rpm. The optimum spray-drying process conditions which maximized the yield of garlic extract powder (31%w/w) were found as follows: air inlet temperature of 150°C, the liquid feed flow rate of 16 rpm, and 5 %w/w MD. The experimental values slightly closed to the corresponding predicted values. Hence, the developed model was adequate and possible to use.

Abstract: Compatibility investigation was performed between stearate lubricants (sodium stearate and magnesium stearate) and acidic pharmaceutical compounds (ibuprofen, indomethacin and valproic acid) and citric acid as acidic pharmaceutical excipient using differential scanning calorimetry (DSC). Alteration in DSC thermogram was found in all mixtures. There was a presence of melting endothermic peak of stearic acid in all mixtures (except that of stearate lubricants and indomethacin) indicating breakage of salt form of stearate lubricants depended on the physicochemical properties of drug compounds and pharmaceutical excipient. Therefore, the avoidance for using stearate lubricants with acidic pharmaceutical compounds and excipient should be concerned in development of pharmaceutical formulations.