Chutima Limmatvapirat

Modulation of drug release kinetics of shellac-based matrix tablets by in-situ polymerization through annealing process

A new oral-controlled release matrix tablet based on shellac polymer was designed and developed, using metronidazole (MZ) as a model drug. The shellac-based matrix tablets were prepared by wet granulation using different amounts of shellac and lactose. The effect of annealing temperature and pH of medium on drug release from matrix tablets was investigated. The increased amount of shellac and increased annealing temperature significantly affected the physical properties (i.e., tablet hardness and tablet disintegration) and MZ release from the matrix tablets. The in-situ polymerization played a major role on the changes in shellac properties during annealing process. Though the shellac did not dissolve in acid medium, the MZ release in 0.1N HCl was faster than in pH 7.3 buffer, resulting from a higher solubility of MZ in acid medium. The modulation of MZ release kinetics from shellac-based matrix tablets could be accomplished by varying the amount of shellac or annealing temperature. The release kinetics was shifted from relaxation-controlled release to diffusion-controlled release when the amount of shellac or the annealing temperature was increased.

Comparison of eleven heavy metals in moringa oleifera lam. products

Eleven heavy metals in various products of Moringa oleifera were analyzed to determine eleven heavy metals (Al, As, Cd, Cr, Cu, Fe, Pb, Mn, Hg, Ni, and Zn) using Inductively Coupled Plasma-Mass Spectrometry. The products of M. oleifera were purchased in Nakhon Pathom, Thailand. All products were digested with nitric acid solution before determining the concentrations of heavy metals. The recoveries of all heavy metals were found to be in the range of 99.89-103.05%. Several criteria such as linearity, limits of detection, limits of quantification, specificity, precision under repeatability conditions and intermediate precision reproducibility were evaluated. Results indicate that this method could be used in the laboratory for determination of eleven heavy metals in M. oleifera products with acceptable analytical performance. The results of analysis showed that the highest concentrations of As, Cr, Hg, and Mn were found in tea leaves while the highest concentrations of Al, Cd, Cu, Fe, Ni, Pb, and Zn were found in leaf capsules. Continuous monitoring of heavy metals in M. oleifera products is crucial for consumer health.

Antioxidant and anticholinesterase activities in various parts of sonneratia caseolaris (L.)

Cork tree, (Sonneratia caseolaris L.), family Sonneratiaceae, is a typical plant in mangroves. It is widespread in tropical and subtropical tideland throughout the World. It is reported to possess many medicinal properties. For searching new pharmacological activities of Cork tree, the total phenolic contents, antioxidant activities and the electric eel acetylcholinesterase inhibitions and the kinetics of extracts of various plant parts were determined. The graphs of trolox equivalent antioxidant capacity and ferric reducing antioxidant power of all extracts showed good linearity with P-value of slopes less than 0.05. The methanol extract of calyxs by maceration method and methanol extract of stamen by soxhlet method presented moderate trolox equivalent antioxidant capacity values. For ferric reducing antioxidant power assay, all extracts gave fair to low antioxidant activities. The tacrine, stamen extract and seed extract by maceration using methanol showed noncompetitive inhibition on acetylcholinesterase activity. While, luteolin, luteolin glycoside and calyx extract and seed extract by boiling using water presented partial noncompetitive inhibition on acetylcholinesterase activity.

Preparation and Characterization of Shellac Fiber as a Novel Material for Controlled Drug Release

The aim of this study was to investigate the effect of electrospinning process on the physical properties of fibers made from shellac. Electrospun shellac fiber was prepared by dissolving shellac in ethanol and then transferred to the electrospinning system. The influences of process parameters; including electric field voltage, tip to collector gap, feeding rate and concentration of shellac solutions; on the spinnability and properties of obtained shellac fibers were elucidated. The result demonstrated that micro-nano fibers of shellac were easily formed after spinning. The concentration of shellac solution was a crucial parameter that determined the spinnability. The electro-sprayed particles of shellac were achieved at the concentration of 35% w/w and lower while the electrospun fibers was formed in the concentration range of 40-45 % w/w. SEM pictures demonstrated that the beaded fiber structure obtained at 40-43% w/w was changed to the continuous fiber structure at 45% w/w. The diameter of fiber showed a tendency to increase while the size distribution of diameter was narrower as increasing voltage. The other optimized electrospinning parameters including feeding rate, tip to collector gap were 0.5-2 ml/h and 15-20 cm, respectively. In conclusion, the study demonstrated the critical parameters that determined the properties of required fibers. The knowledge gained should support the development of the drug incorporated electrospun shellac fiber in near future.

Formulation and evaluation of gels containing coconut kernel extract for topical application

The biological activity of coconut (Cocos nucifera L.) extracts from its kernels and various parts was reported by many previous studies, it is therefore believable that the extracts of its kernels might show some activities in topical formulations. Among several kernel extracts, the TC06 extract prepared by soaking the steamed coconut kernels in hot water showed the highest total phenolic content (6.98 ± 0.30 mg GAE/g extract) and the strongest antioxidant activity as determined using FRAP and DPPH methods with a reducing power value of 4.12 ± 0.16 mg AAE/g of extract and an SC50 value of 2.38 ± 0.14 mg/ml, respectively. In addition, this extract did not display any cytotoxic effects in the concentration range of 50–3200 µg/ml. Meanwhile, it revealed cytoprotective effects against t-BHP-induced cytotoxicity in HaCaT cells at concentrations higher than 400 µg/ml. The results of phytochemical investigations including a chemical color test, TLC, 1H NMR and FTIR suggested that the TC06 extract was mainly composed of flavonoids and terpenoids. Furthermore, the concentrations of heavy metals including As, Cd, Hg, and Pb in the TC06 extract were below permissible limits. According to the solubility, the TC06 extract was incorporated into gels using Carbopol Ultrez 21 as a gelling agent. The formulated gel containing 3% (w/w) TC06 extract was stable at 4 °C and 25 °C with 75% RH throughout the storage period. It was found that the Carbopol Ultrez 21-based hydroalcoholic gel containing an aqueous extract of coconut kernels exhibited antioxidant activities in the two assays and showed a sufficient consistency, a pleasing color, and a non-oily perception during the period of observation.

The effect of surfactant on the physical properties of coconut oil nanoemulsions

The aim of this study was to develop the water compatible form of coconut oil through nano-emulsification. The effect of different types and amounts of surfactants on the physical characteristics of nanoemulsions containing coconut oil was investigated. Coconut oil nanoemulsions containing varied amounts of surfactants including polyethylene glycol octyl phenyl ether (PGO), polyoxyethylene sorbitan monostearate (POS), polyethylene glycol hydrogenated castor oil (PHC), sodium lauryl sulfate (SLS) and poloxamer 407 (PLX) were formulated and comparatively evaluated for their physical properties. The results showed that the coconut oil nanoemulsions using PGO, POS and PHC as surfactants exhibited low percent creaming index indicating excellent stability, while those containing SLS and PLX demonstrated the higher percent creaming index suggesting lesser physical stability. The droplet sizes of nanoemulsions consisting of 5% (w/w) PGO, POS and PHC were 22.843, 4.458 and 0.162 µm, respectively. Thus, coconut oil nanoemulsions with the smallest size could be obtained when PHC was applied. Furthermore, the droplet size of nanoemulsions decreased from 33 µm to less than 200 nm with an increase in the amount of PHC from 1% to 10% (w/w). Additionally, the properties of coconut oil based nanoemulsions containing PHC were not changed through temperature cycling test. From these results, it was suggested that the fabrication of stable coconut oil nanoemulsions with small particle size could be easily achieved by using 5% (w/w) PHC as a surfactant. The knowledge gained from the study might provide the basic guideline for the fabrication of stable nanoemulsions for food, cosmetic and pharmaceutical fields in the future.

Fabrication and characterization of spearmint oil loaded nanoemulsions as cytotoxic agents against oral cancer cell

Spearmint oil (SMO), a commonly used essential oil for oral care products, possesses various interesting functions, especially for anticancer property. However, the application of SMO for cancer treatment is limited due to water insoluble. In the present study, nanoemulsions, which have been widely accepted as dosage forms for poorly water-soluble drugs, were selected as candidate carriers for SMO to inhibit oral cancer cell. The nanoemulsions were fabricated using phase inversion temperature method. The factors affecting formation and properties of nanoemulsions including type and amount of surfactants, oil loading and ratio of SMO to virgin coconut oil (VCO) were investigated. Among the surfactants used, the nanoemulsions containing polyoxyethylene castor oil derivatives (Kolliphor®EL; PCO35, Cremophor®RH40; PCO40, Eumulgin®CO60; PCO60) and polyoxyethylene sorbitan fatty acid esters (PSF80) showed 100% creaming after temperature cycling test indicating excellent physical stability while those containing PCO40 demonstrated more transparency and better physical stability. With an increasing amount of PCO40, the droplet size tended to decrease and was in the nano-size range (<1000 nm) after increasing to more than 5% (w/w). SMO-VCO loading also influenced on the droplet size. At 5% (w/w) PCO40, the maximum SMO-VCO loading of 25% (w/w) to attain nanoemulsions was observed. Moreover, the composition of oils had an impact on size of emulsions. The transparent nanoemulsions were only prepared in the range of SMO-VCO from 40:60 to 80:20, suggesting the optimum ratio of SMO to surfactant and the composition of oils were the critical factors for formation of nanoemulsions. NMR study disclosed that the interaction between PCO40 with both VCO and SMO should be a possible stabilization mechanism. Furthermore, the SMO-VCO nanoemulsions exhibited significant cytotoxic effect against oral carcinoma (KON) cell line using MTT assay. The finding, therefore, revealed the good feasibility of SMO-VCO nanoemulsions as novel carriers for treating of oral cancer.

Design and characterization of monolaurin loaded electrospun shellac nanofibers with antimicrobial activity

Graphical Abstract The shellac nanofibers loaded with monolaurin were prepared by electrospinning technique based on a full factorial design. The obtained nanofibers exhibited antimicrobial activities against Staphylococcus aureus and Candida albicans over a period of time. Image, graphical abstract

Factors Affecting Formation of Emulsions Containing Soybean Oil

The aim of study was to prepare a water compatible form of soybean oil through nanoemulsification. Factors affecting properties of nanoemulsions containing soybean oil such as types and amounts of surfactants (Tween 60, Cremophor RH-40, sodium lauryl sulfate (SLS) and Lutrol F-127) were investigated. The results demonstrated that types and amount of surfactants affected the formation and physical stability of nanoemulsions. The emulsions containing Cremophor RH-40 and Lutrol F-127 showed 100% creaming while those containing Tween 60 and SLS indicated the lower percentage of creaming suggesting the less physical stability. However, the formation of nanoemulsions was not observed in the formula containing Lutrol F-127. The average droplet size of emulsions was 1766 nm and 193 nm for emulsions containing 5% w/w Lutrol F-127 and Cremophor RH-40, respectively. The droplet size was also affected by the amount of Cremophor RH-40. The droplet size was decreased from 795 to 114 nm as increasing amount of Cremophor RH-40 from 2.5 to 10 %w/w. Additionally, the properties of nanoemulsions containing Cremophor RH-40, including physical appearance, droplet size and zeta potential, were not change even after temperature cycling. In conclusion, the more water compatible form of soybean oil was accomplished through incorporation into the nanoemulsions with specific type and amount of surfactant.

Simplified Qualitative Analysis of Glycerides Derived from Coconut Oil Using Thin Layer Chromatography

Coconut (Cocos nucifera L.) oil is composed predominately of medium-chain triglycerides which have been reported to be beneficial to human health. It also contains free fatty acids (FFAs) which can combine with glycerol to form monoglycerides, diglycerides, and triglycerides. The analysis of FFAs and their glycerides has been proposed to assess the quality of coconut oil used as raw materials in various industrial fields. The aim of this study was to develop the qualitative method for investigation of FFA and their glycerides in coconut oil using thin layer chromatography (TLC). Coconut oil and standards of FFA and their glycerides were chromatographed separately on Silica gel 60 F254 TLC plates using hexane: ether: acetic acid (60:40:1) and hexane: ethyl acetate: acetic acid (60:40:0.5) as solvent systems A and B, respectively. The spots on developing TLC plates were detected and compared using 254-nm UV light and iodine vapor. The results showed that the resolution of solvent system A was better than that of solvent system B. However, both solvent systems were used to confirm the results. The retention factor (Rf) values of the components were in good agreement with their polarity. This method should provide a guideline for qualitative analysis of coconut oil.