Papers by Keyword: HPMC

Abstract: The objective of this study was to investigate the effect of polymers and their content level on the taste-masking efficiency of spray-dried microparticles. Diclofenac sodium (DS) was used as a model drug, owing to its bitter taste. Hydroxypropyl methylcellulose F4M (HPMC F4M) and Eudragit^® E PO were involved in the study as a hydrophilic and a pH-responsive polymer, respectively. The taste-masked DS microparticles with the drug:polymer ratios of 1:1, 1:2 and 1:4 were prepared by the spray-drying technique. The collapsed hollow sphere HPMC F4M based-microparticles was observed meanwhile spray-dried Eudragit^® E PO based-microparticles were spherical. Loading capacity of both polymer based-microparticles decreased regarding to the increment of drug:polymer ratio. The Eudragit^® E PO based-microparticle in the ratio of 1:4 provided the highest loading efficiency as 91.97%. According to the simplified dissolution testing, the taste-masking ability of HPMC F4M and Eudragit^® E PO based-microparticles increased upon the increase of drug:polymer ratio. Drug release at the first 5 minutes from dissolution profiles, tested by type II dissolution apparatus, of the Eudragit^® E PO based-microparticles was delayed compared to HPMC F4M based-microparticles. Therefore, it could be assumed that Eudragit^® E PO was a promising taste-masking polymer for DS with a pleasant taste.

Abstract: The number of blindness is tend to be increased year by year. One of the blindness cause is cornea ulcer.The cause of cornea ulcer is bacteria, fungi, and herpes simplex virus. Cornea transplantation is the only treatment which could widely accepted for blindness. Transplant by donor network becomes the only treatment that is acceptable on a large for blindness. However, treatment donor transplants have many shortcomings in complications post surgery such as host response, donor limitations, incompatibility and the length of time healing. As technology develops, there are many corneal substitutes based on natural ingredients derived from collagen or their derivatives because they promise better properties in biocompatibility. The aim of research are to conduct the synthesis and characterization of collagen- chitosan- glycerol - HPMC as artificial cornea such functional cluster test, cytotoxycity test, morphological test and antibacterial test. Based on functional cluster test, there are functional groups of all components of composite materials. While from cytotoxicity test, all samples have a percentage of living cells above 85%. The morphology test is showed that the pore size of sample B with composition collagen-chitosan-glycerol-HPMC is in accordance with the standard pore size for keratoprothesis. Sample A (collagen-chitosan-glycerol) and sample B (collagen-chitosan-glycerol-HPMC) have strong antibacterial properties.Biocomposite of collagen-chitosan-glycerol could be considered as artificial cornea due to the proximity with the corneal characteristics.

Abstract: The present study focuses on characterization the physical properties of liposome formulation which was dispersed in HPMC matrix and lyophilized in the presence of disaccharides. The lyophilized formulations featured cationic dimethyldioctadecylammonium (DDA) to produce dry solid and overcome limitations in terms of detrimental phase separation in phospholipid membranes during production process. Disaccharides, such as sucrose and lactose, have been reported to protect phospholipid membranes during drying, while HPMC was used as dispersed matrix to inhibit recrystallization of disaccharide. Their physical properties were characterized including their morphology using scanning electron microscopy (SEM), crystallinity using x-ray diffractometry (XRD), and solid phase separation using differential scanning calorimetry (DSC). On the basis of these evaluations it was found that the presence of sucrose and HPMC in the formulation showed a miscible mixture and relatively less crystalline-forming properties compared to those using lactose, thus potentially construct a stable dried liposomal formulation. The present study reveals prospective advantages of using combination of sucrose and HPMC in development of dried–DDA liposomal formulation.

Abstract: The aim of this research work was to develop the controlled release of two model drugs i.e. water insoluble drug - resveratrol and water soluble drug - lignan by matrix tableting with an eccentric tablet machine. For this purpose different kinds of polymers i.e. Metolose 90 SH-4000^® (HMPC), Fetocel RT-N-100^® (EC) and Eudragit RLPO^® (polymethacrylate) were used. The matrix tablets containing 2 %wt of a model drug which were mixed with 5, 10, 20, 30 and 50 %wt of the polymers mentioned above. In addition, a glidant composed of 1 %wt talc and 1 %wt magnesium stearate as well as a filler Ludipress^® were processed. Different physical properties of the powder mixtures (e.g. flowability) and of the tablets (e.g. hardness, uniformity of mass or drug content, drug release, etc.) were determined. Most of the tablets met the physical requirements. If the polymer content got higher the release was slower, which can be confirmed by the lower values of k. The release kinetics were described by three typical mathematic models i.e. biphasic, Noyes-Whitney and KorsmeyerPeppas. The best fitting results were ordered as follows: biphasic > Noyes-Witney > KorsmeyerPeppas.

Abstract: In this paper, the influences of different binders (Hydroxypropyl Methyl Cellulose (HPMC), Carboxymethyl Cellulose Sodium (CMC), Polytetrafluoroethylene (PTFE) and Styrene- butadiene Rubber (SBR)) on high-rate discharge performances at low temperature for the negative electrode of Ni/MH battery have been studied by orthogonal experimental design. Electrochemical measurements have been conducted to investigate the capacity, charge-discharge performance, cyclic voltammetry and electrochemical impedance characteristics. The surface morphology and chemical compositions have been investigated by SEM and EDS. Based on the range analysis, the primary and secondary influence factors as well as the optimization results were obtained. From the CV characteristic curves, the oxidization peaks and reduction peaks are not clearly shown, which indicates that the redox reaction does not occur clearly after binders added. The EIS experiments show that the deterioration of the voltage characteristic of the battery is due to drying out of the separator that increases the ohmic resistance (Rs ), and the decay of the discharge capacity is due to the passivity surface that increases the charge-transfer resistance (Rt) of the battery.

Abstract: A series of aqueous solutions of blends based on polyethylene oxide (PEO) and hydroxypropyl methyl celloulose (HPMC) were prepared. The solution of the blends thus obtained was analyzed for miscibility. The effects of compositions of blends and temperature (30 and 500C) on miscibility have been reported. The Huggin plots deviate from linearity according to the degree of compatibility of PEO/HPMC blends at entire concentration range. Interaction parameters have been evaluated for all blends to probe the miscibility. The blends were also characterized by sophisticated techniques such as FTIR, DSC, TGA and SEM.

Abstract: An injectable bone substitute (IBS) made of a suspension of calcium phosphate ceramic was used to filled dental root canal after removing of canal pulp. Compared with current filling materials, which are toxic to periapical tissues, calcium phosphate materials, due to their biocompatibility and bioactive properties, may be viewed as possible alternatives. The aim of this study was first to determine if an injectable bone substitute could be used to obtain further healing of apical tissue by the neoformation of a mineralized barrier. In the next step, the paper will focus on rheological measurements as a tool for physical characterisation and on the improvement of the injection technique. Rheology concerns the flow and deformation of the suspension and, in particular, its behaviour in the transient area between solids and fluids. The results showed that injection is possible with a good level of BCP granules at the end of the root dental canal with extracted tooth. Other experiments with other animal models closer to a Human model have to be performed before human trials.