Papers by Author: Theerasak Rojanarata

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Authors: Natthan Charernsriwilaiwat, Theerasak Rojanarata, Tanasait Ngawhirunpat, Praneet Opanasopit
Abstract: The aim of this study was to investigate the antioxidant activities of chitosan acetate (CS-acetate), chitosan hydroxybenzotriazole (CS-HOBt), chitosan thiamine pyrophosphate (CS-TPP) and chitosan ethylenediaminetetraacetic acid (CS-EDTA) nanofiber mats. Chitosan was dissolved with hydroxybenzotriazole (HOBt), thiamine pyrophosphate (TPP) and ethylenediaminetetraacetic acid (EDTA) in distilled water. These chitosan aqueous salts were blended with polyvinyl alcohol (PVA) at volume ratio 30/70 chitosan salts/PVA and prepared to nanofibers via electrospinning process. The morphology of electrospun chitosan aqueous salts based nanofiber mats were observed under scanning electron microscope (SEM). The antioxidant activities were determined employing various established in vitro system such as superoxide, hydroxyl radicals scavenging and metal ion chelating compared with pure PVA nanofiber mats. The results exhibited that the electrospun chitosan aqueous salts based nanofiber mats showed the different antioxidant activity depended on salt forms. Among the salt forms, CS-acetate nanofiber mats showed the highest superoxide radical scavenging effect while CS-HOBt nanofiber mats (IC50 = 7.53 mg/mL) showed the highest hydroxyl radical scavenging effect. For the metal ion chelating activity, CS-EDTA nanofiber mats showed the highest chelating activity (IC50 = 1.07 mg/mL). In summary, the antioxidant chitosan aqueous salt based nanofiber mats have potential for use in pharmaceutical applications.
Authors: Maleenart Petchsangsai, Nanthida Wonglertnirant, Theerasak Rojanarata, Praneet Opanasopit, Tanasait Ngawhirunpat
Abstract: The objective of the present study was to use hollow microneedles for enhancing the transdermal delivery of Bovine Serum Albumin (MW~66,000 Da)-Fluorescein Isothiocyanate (BSA-FITC) conjugate, a hydrophilic large molecular compound. BSA-FITC was successfully loaded into the lower epidermis as well as the superficial dermis of the skin of neonatal pig by a hollow microneedle. The higher the volume of BSA-FITC solution injected, the higher the amount and the faster the BSA-FITC release rate from skin. These release profiles of BSA-FITC solution were expressed by Fick’s law of diffusion. These results suggest the utilization of hollow microneedle to enhance transdermal delivery of protein and provide useful information for designing an effective hollow microneedle system.
Authors: J. Kowapradit, Theerasak Rojanarata, Tanasait Ngawhirunpat, A. Apirakaramwong, Warayuth Sajomsang, Praneet Opanasopit
Abstract: In the present study, methylated N-(4-N,N-dimethylaminocinnamyl) chitosan (TM65CM50CS) was synthesized and investigated for oral protein drug delivery by combining with liposomes entrapped bovine serum albumin (FITC-BSA), a model protein. FITC-BSA liposomes composed of egg yolk phosphatidylcholine and sodium oleate in molar ratio of 10:2 were prepared by thin film hydration method. The TM65CM50CS coated liposomal FITC-BSA was evaluated for transport of protein and its cytotoxicity in Caco-2 cells. Moreover, the in vitro stability of BSA in TM65CM50CS coated liposomes was also examined by the degradation of protein from pancreatin. The mean particle size and zeta-potential of liposomes were 101+0.02 nm and -27.44+2.02 mV, respectively. Initial FITC-BSA (2.5% w/w) to lipid showed the highest percentage entrapment efficiency (50.13%) and FITC-BSA content (8.08 mg/g of lipid). The results of FITC-BSA transport showed that TM65CM50CS coated FITC-BSA liposomes enhanced protein permeability across Caco-2 cell monolayers with low cytotoxicity. In addition, these liposomes could protect the degradation of protein from pancreatin. Our studies demonstrated that TM65CM50CS coated liposomes have the potential to be used as an oral protein drug delivery.
Authors: Tittaya Suksamran, Theerasak Rojanarata, Tanasait Ngawhirunpat, Suwannee Panomsuk, Praneet Opanasopit
Abstract: The aim of this study was to prepare Caalginate and chitosan (CS)Caalginate microparticles for peroral delivery of ovalbumin (OVA). Microparticles containing different loading of OVA (10, 20 and 40 % w/w) were prepared by cross-linking alginate with calcium chloride using an electrohydrodynamic spraying technique, and then coated with CS. The particle sizes of OVA-loaded microparticles were in the range of 1-5 µm. The negative charge was obtained for Caalginate microparticles (-14±1.9 mV) whereas CSCaalginate microparticles were positive charge (+6.06±3.4 mV). Caalginate microparticles with initial 20% w/w OVA showed the highest entrapment efficiency and amount of OVA content (24.91±0.4% and 33.22±0.1 mg/g, respectively) as similar to CSCaalginate microparticles with initial 20% w/w OVA that showed the highest entrapment efficiency and amount of OVA content (35.74±0.1% and 10.35±0.5 mg/g, respectively). It was found that the release rate of OVA from Caalginate microparticles was higher than CSCaalginate microparticles, and the lowest release rate, sustained release for 24 h, was found in the initial 40% w/w OVA. This study revealed that CSCaalginate microparticles have a considerable potential as controlled release antigen delivery systems.
Authors: Nanthida Wonglertnirant, S. Tipwichai, Praneet Opanasopit, Theerasak Rojanarata, Suwannee Panomsuk, Tanasait Ngawhirunpat
Abstract: Ketoprofen transdermal patches (KTPs) were fabricated using an acrylic pressure sensitive adhesive (PSA) polymer. The influence of different factors (amount of PSA, drug content, and pressure applying on the backing membrane during preparation) on the characteristics of ketoprofen patch (thickness, W/A ratio, and adhesiveness of matrix film) and in vitro drug release behavior were investigated. The results revealed the successful fabrication and a good physical appearance of KTPs using acrylic PSA. Microscopic observations, FTIR spectra, and DSC thermograms were permitted to demonstrate that the drug was dispersed molecularly in the polymer. As the amount of PSA in the adhesive matrix was increased, the release rate of ketoprofen was decreased. Contrarily, the drug release rate was increased corresponding to the increase of ketoprofen content in the adhesive matrix. There was no significant difference in the release rate when the pressure applying on the backing membrane was varied. The kinetic of ketoprofen release from acrylic matrix type transdermal patches followed the Higuchis diffusion model.
Authors: Theerasak Rojanarata, Kwanrutai Waewsa-Nga, Parin Buacheen, Praneet Opanasopit, Tanasait Ngawhirunpat
Abstract: An environmentally friendlier, safer and saver method is described for the assay of drugs as hydrochloride salts namely metformin hydrochloride and phenylpropanolamine hydrochloride via the determination of their chloride contents. In this method, an aqueous solution of drug was treated with measured excess of silver nitrate in the presence of nitric acid, followed by the determination of unreacted silver nitrate by Volhard’s method using ammonium thiocyanate titrant and iron(III) alum indicator. To minimize the reagents consumed and wastes generated, the reactions were scaled down to less than 2 mL carried out in microcentrifuge tubes and using micropipettes for the transfer of reagents. The equivalence point was determined by spectrophotometry to diminish visual errors by reading the absorbance of red iron(III) thiocyante complex at 450 nm on microplates, which quickened the measurements of multi-samples. After validation, the method showed satisfactory accuracy and precision and was successfully applied for the assay of both drugs in raw materials, giving the results comparable to the pharmacopeial methods. In addition, the proposed assay was free from the use of harsh, toxic and environmentally harmful chemicals i.e. glacial acetic acid, acetic anhydride, mercuric acetate which are employed in the USP non-aqueous titration methods. Thus, the method is considerably safer for analysts and is a cost-effective and green analytical method suitable for a sustainable environment.
Authors: Narumon Worachun, Praneet Opanasopit, Theerasak Rojanarata, Tanasait Ngawhirunpat
Abstract: The aim of this study was to prepare microemulsion for transdermal drug delivery of ketoprofen (KP). The physicochemical and chemical properties of microemulsion were evaluated. The microemulsion were composed of isopropyl myristate (IPM) as oil phase, water, PEG40-hydrogenated castor oil (Cremophor® RH40) as surfactant and PEG400 as co-surfactant, and the surfactant: co-surfactant ratio used was 1:1. The viscosity, droplet size, pH, conductivity of microemulsion and skin permeation of KP through shed snake skin were evaluated. The particle size, viscosity and conductivity of microemulsions were in the range of 172-468 nm, 234.82-1067.35 cP and 6.80-20.87µS/cm, respectively. The ratio of IPM and surfactant mixture played an important role on KP loading capacity of microemulsions formulation and skin permeation of KP. While amount of surfactant increased, the loading capacity of KP increased, but the skin permeation of KP decreased. The results suggested that the novel microemulsion system composed of IPM, water, Cremophor® RH40:PEG400 (ratio 1:1) can be applied for using as a transdermal drug delivery carrier.
Authors: P. Chareanputtakhun, Theerasak Rojanarata, Praneet Opanasopit, Tanasait Ngawhirunpat
Abstract: NLCs are second generation of lipid nanoparticles which have many advantages that make them interesting for topical drugs delivery systems. All-trans retinoic acids (ATRAs) are highly lipophilic and instable in the presence of air, light and heat. In this study, 0.3% ATRAs loaded NLCs were developed by de novo emulsifications, then were reduced to nanometer range by ultrasonicator. The characterizations of NLCs i.e. size and zeta potential were examined. NLCs with different solid:liquid lipids ratios (2:1, 1:1 and 1:2), were formulated in order to maximize the skin permeation. The results demonstrate the sizes of NLCs were in nanometer ranges with negative zeta potential. Moreover the results showed that the amount of solid lipids in the formulation affected the skin permeation. The highest ATRAs permeations though shed snake skin could be achieved from the NLCs which lipid matrixs were composed of 2:1 solid:liquid lipids ratios.
Authors: T. Nitanan, Prasert Akkaramongkolporn, Theerasak Rojanarata, Tanasait Ngawhirunpat, Praneet Opanasopit
Abstract: In this study, polystyrene nanofiber ion exchangers (PSNIE) were successfully prepared by a new method comprising of electrospinning and the subsequent crosslinking with formaldehyde and sulfonation in sulfuric acid to create the cation exchange functionality on the fibers surfaces. The PS solution at 15% w/v in dimethylacetamide (DMAc) produced the smallest PS nanofibers (399±38 nm) with good performance. The degree of crosslink and ion exchange capacity (IEC) of PSNIE depended upon the crosslinking time. The longer crosslinking time caused the greater crosslinked PS fibers. At the longest crosslinking time of 75 min, the remaining crosslinked PS fibers in dichloromethane were 94.12%; whereas, the starting fibers completely dissolved. This crosslinking agent (e.g. formaldehyde) might introduce methylene bridges in addition to sulfone bridges into the fibers. However, IEC decreased as crosslinking time increased, probably due to the difficulty of sulfonic functional groups to react with crosslinked PS fibers. The PSNIE crosslinked for 10 min showed the maximum IEC of 2.86 meq/g-dry-PSNIE, and the diameter of the PSNIE after sulfonation increased to 450-460 nm. Since cationic drug could be loaded onto this novel PSNIE, this nanofiber ion exchanger may be applied for controlled release delivery.
Authors: Sureewan Duangjit, Praneet Opanasopit, Theerasak Rojanarata, Tanasait Ngawhirunpat
Abstract: The aim of this study was to prepare and investigate the potential use of liposomes in the transdermal drug delivery of meloxicam (MX). The vesicles containing a constant amount of MX, phosphatidylcholine (PC), cholesterol (Chol) and cetylpyridinium chloride (CPC) (1:5:1:1 MX/PC/Chol/CPC molar ratio) to obtain liposomes. MX loaded liposomes were investigated for particle size, zeta potential, entrapment efficiency (%EE) and in vitro skin permeation. The results indicated that the liposomes were spherical in structure, 77 to 100 nm in size and charged. The %EE of MX in the vesicles ranged from 55 to 56%. The elastic liposomes consisting of MX/PC/Chol/CPC provided a significantly higher skin permeation of MX compared to the other formulations. Fourier Transform Infrared Spectroscopy (FT-IR) and Differential Scanning Calorimetry (DSC) analysis indicated that the application of liposomes may disrupt the stratum corneum lipid. Our research suggests that MX loaded elastic liposomes can be potentially used as a transdermal drug delivery system.
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