Comparison Drug Release from Simple and Layered Matrix Systems Containing Hydroxypropyl Methylcellulose

Objective: The aim of this investigation was to compare the release behavior of propranolol HCl from simple matrix and layeredtablets containing HPMC and phytowax as matrix component using direct compression technique.Method: The test of drug release was performed in distilled water during 26 hrs using a dissolution apparatus and thereafter thedissolution profile fitting to different mathematical equations was carried out using least square fitting with a nonlinear computerprogram, Scientist for Windows, version 2.1.Results: Covering both planar surfaces of drug-loaded middle layer was able to attain a more sustainable drug release than asimple matrix which composed the same amount of matrix component. Additionally, the near-zero order release could beobtained for the first system whereas the drug release from simple matrix tablet was diffusion-controlled. As the number oramount of coating layer, and amount of matrix component in middle layer were increased, the drug release was noticeablyprolonged. Drug release from layered tablets was influenced by hydrodynamic force and incorporated diluents.Conclusion: Effective near-zero order controlled release of hydrophilic drug was obtained from three-layered matrix tabletscomprising HPMC as main matrix component. Modulation of drug release could be conducted by addition or increasing amountof water soluble substances into the matrix component of three-layered tablets.Key words: drug release, comparison, simple layered-matrix, layered-matrix, hydroxypropyl methylcelluloseThai Pharm Health Sci J 2008;3(2):219-228

Effect of Particle Size of Chitosan on Drug Release from Layered Matrix System Comprising Chitosan and Xanthan Gum

Biopolymers such as chitosan and xanthan gum were applied as matrix component for fabrication into tablet using a direct compression technique to control the release of propranolol HCl. Covering both planar surfaces of middle tablet with polymeric mixture containing chitosan-xanthan gum-lactose could modulate the release of propranolol HCl. Increased amount of lactose enhanced the drug release and diminished the pH sensitive drug release of tablet containing chitosan and xanthan gum. However, the drug release from the three layer tablets comprising this system was pH dependent. Particle size of chitosan did not significantly affect the drug release from the three layer tablets comprising this system. The drug release behaviour from the developed tablets was characterized with the curve fitting with different mathematical equations and the water & erosion studies.Key words: chitosan, drug release layered matrix, particle size, xanthan gu

Drug Release through PEG-Xanthan Gum-Lactose Matrix Comprising Different Amount of Drug

Objective: The purpose of this study is to investigate the effect of xanthan gum and lactose on the physical and releaseproperties of 25-mg and 75-mg indomethacin tablets containing polyethylene glycol (PEG) prepared by mold technique. Method:The physical and drug release characteristics of developed matrix tablet were studied. Least square fitting the experimentaldissolution data to the mathematical expressions (power law, first order, Higuchi’s and zero order) was carried out. Results:Because of the more completion dissolution of drug in PEG matrix, the drug release from the lower-drug loading tablet wasfaster than the higher-drug loading tablet. An addition of xanthan gum could sustain the drug release whereas an addition oflactose diminished the drug dissolution. From curve fitting, most drug release profiles were primarily as Fickian diffusion.Conclusion: Amount of indomethacin played an important role on the drug released from PEG matrix consisting xanthan gumand lactose prepared with fusion and mold technique. Xanthan gum and lactose also affected the physical and releasecharacteristics of these investigated indomethacin tablets.Keywords: Characterization, drug, release, mold tablet, hydroxypropyl methylcellulose, polyethylene glycolThai Pharm Health Sci J 2009;4(2):153-163

Thermal Properties and Rheological Behaviors of the Anesthetic Gel Containing Lidocaine and Prilocaine

Objectives: To develop a gel containing lidocaine and prilocaine and to characterize its thermal and rheological properties. Methods: The thermal property by differential scanning calorimeter (DSC), solubility of the drugs in co-solvent system, suitable gelling agent and rheological behavior were evaluated. Results: DSC study revealed that lidocaine:prilocaine at the ratio of 1:1 could form a eutectic mixture. The co-solvent system, 35% w/w ethanol was used to dissolve these drugs. The 1% w/w carbopol 940 was an appropriate gelling agent. The developed gel and EMLA® cream showed a comparable pseudoplastic flow (shear thinning system). In addition, the changing of temperature did not affect the gels’ rheological behavior. Conclusion: This study of the lidocaine-prilocaine gel formulation can be useful for the further development. Keyword: lidocaine, prilocaine, gel, eutectic mixture, thermal properties, rheological behavior

Total Phenolic Content and Antioxidant Activity of Fresh and Preserved Fruits of Ellaeocarpus hygrophilus Kurz.

Objective: To determine the total phenolic content and antioxidant activities of fresh Spanish plum fruits (Ellaeocarpus hygrophilus Kurz., family Elaeocarpaceae.) in various ages and to examine the influence of preserved methods which were chilling and pickling on the total phenolic content and antioxidant activities of the fruit. Method: The meat of Spanish plum fruit was preserved by storage at -70, -4, 0 and 4 °C for 1, 4 and 6 months. Results: The duration and temperature of storage resulted in no significant effect on pH of the fruit juice. The various durations of chilling showed no significantly different effect on % brix of the fruits, but lower chilling temperature was associated with increased % brix. The younger fruit contained higher amount of total phenols in its crude extracts and juice than the older ones. The duration of chilling showed no effect on total phenols of the fruits. The duration and temperature of chilling of the fruits before juice squeezing gave significant decreasing effect on the amount of total phenols in the juices. The antioxidant activities of the fruits with all ages were low. The duration and temperature of chilling and prickle duration of the fruits had no significant effect on antioxidant activities. Conclusion: The preserved condition could save pH, % brix, amount of total phenol and antioxidant activities of the Spanish plum fruit.Keywords: Spanish plum, Ellaeocarpus hygrophilus Kurz, antioxidant activity, phenolic compounds, preserved frui

HPMC Matrix Granule Formation: Selection of Suitable Granulating Fluid

Objective: The purpose of this study was to investigate and select the suitable granulating fluid for the matrix granules consisting of hydroxypropyl methylcellulose (HPMC).Method: Viscosity of the granulating fluids containing HPMC in different solvents was determined. The matrix granules obtained from mixing the granulating fluid with propranolol HCl, HPMC and lactose were assessed for bulk density, particle size distribution, flowability and friability. SEM, DSC, powder x-ray diffraction and drug dissolution studies were conducted to characterize the physical properties of the granules.Results: Type of granulating liquid affected the granule properties. The utilization of isopropyl alcohol as a granulating liquid and subsequently adding with water was a suitable system for agglomeration of powders. Good physical properties were obtained for the granule prepared by using this granulating fluid.Conclusion: Type of solvent and amount of water played an important role for physical properties of HPMC in the formation of the matrix granule due to the hydrophilicity and gel formation of this polymer. The use of isopropyl alcohol as granulating liquid and subsequently adding with water was a suitable process in producing the matrix granules consisting of HPMC.Keywords: hydroxypropyl methylcellulose, matrix granule, granulating flui

เทคโนโลยีหุ่นยนต์ขนาดไมโครเมตรหรือนาโนเมตรเพื่อใช้ทางการแพทย์และเภสัชกรรม Micro or Nano-robotic Technology for Medical and Pharmaceutical Applications

Abstract Nowadays the development of robots in medicine or pharmaceutical applications is important for disease diagnosis and drug delivery system. The goal of this study is to increase the efficiency of diagnosis or treatment to facilitate drug delivery and reduce the side effects of traditional treatment. Most designed robotic technology delivers the machine into an area where the disease or disorder occur which the tiny robots as micro and nano-scale are required using complex designs with different technologies including mechanical and chemical procedures. Keywords: robotic technology, micrometer, nanometer, medical, pharmaceutica

Eutectic System in Pharmaceutical Applications

Eutectics are mixtures of at least two compounds with a uniqueproperty that such system has a lower melting temperature than thatof either constituent alone. This decrease in melting point can bescrutinized profoundly from thermodynamics theory which suggeststhat there is an increase in total entropy of the system. Furthermore,such thermodynamic equation could be utilized to determine theeutectic critical parameters such as eutectic point or eutecticcomposition employing the data form differential scanningcalorimetric and hot stage microscope. With the increasing totalentropy, the solubility and permeability ability of eutectics areenhanced apparently. Some liquid eutectics can be utilized assolvent/co-solvent system, and biotransformation medium. Somedrawbacks of eutectics include formulary incompatibilities which mayaffect stability or properties of the formula.Keywords:eutectic, thermodynamic, theory, pharmaceutica

Utilization Feasibility of Emulsifying Polymers in Cream Base

ABSTRACTObjective: Emulsifying polymer has been employed for low energy emulsification. This study investigated effect of some crucial factorson the physical properties of cream prepared from these polymers. Method: Systems containing various emulsifying polymers, distilledwater and isopropyl isostearate were prepared. Formula and process variables including type and amount of emulsifying polymer, typeand amount of solvents, and order of mixing on physical properties of cream base, were evaluated. Results: Viscosity of emulsions wasincreased as amount of emulsifying polymer was increased. Additionally, viscosity of systems depended on the type of emulsifyingpolymer and the type of solvent. Viscosity of formulation was different as order of mixing was changed. Conclusion: Type and amount ofemulsifying polymers or solvent and order of mixing notably affected viscosity of cream base. However, these polymeric emulsifiers havepotential use for emulsion both in pharmaceutical and cosmetic products.Keywords: cream base, emulsifying polymers, utilizationThai Pharm Health Sci J 2009;4(4):456-462

Temporary Chemical Depilation

Some mankind groups desire the smooth skin without the covering hair forgood touch or clean feeling therefore the unwanted hair removal wasstudied. Temporary chemical depilation employs some chemicals such asthioglycolates that can hydrolyze and break the disulfide bond in cysteineunit of hair keratin. This allows for hair weakness and its easy removal. Theother components of a depilatory formula are surface active agent, binder,alkaline pH adjustor and hair penetrator which are added to promote thedepilatory efficiency. The skin irritation and dark point from remaining hairshould be aware at depilation site. In addition, the hydrogen disulfide gasformation will be occurred. Papain and eflornithine have been reported tobe used for hair removal. The interest of searching is the natural-basedsubstances for hair removal and decrease the hair growth; however there isthe limitation from the instability of most compounds in alkaline environmentduring chemical depilation.Keywords: hair, removal, chemical, temporar