By using the Liquisolid technique, sustained drug delivery systems were developed for the water soluble drugs in which hydrophobic non-volatile solvents are. Abstract. Liquisolid technique is also known as powder solution technology. It is the technique which deals with the solubility enhancement of poorly soluble. Acta Pharm. Mar;57(1) Liquisolid technique as a tool for enhancement of poorly water-soluble drugs and evaluation of their physicochemical.
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Journal of Drug Delivery and Therapeutics3 4 Powdered liquid drug Powdered drug solutions. Effect of powder substrate on the dissolution properties of methyclothiazide liquisolid compacts. Dissolution profile enhancement occurs in the presence of low levels of hydrophilic carrier, where coating material is not significant. In the study, he suggested flowability of a powder is of major importance in the production of pharmaceutical dosage forms in order to attain a uniform feed and reproducible filling of tablet dies.
The loose bulk density and tapped density were determined by using bulk density apparatus apparent bulk density was determined by pouring the blend into a graduated cylinder. Such lack of crystallinity in the liquisolid system was understood to be as a result of drug solubilisation in the liquid vehicle i.
Concept of liquisolid technique: Liquisolid technique is a novel approach toward the development of dry, nonadherent, free-flowing, and compressible powder from the drug in liquid state.
The Liquisolid technique: an overview
Biopharmaceutics and Pharmacokinetics A treatise. Significant differences in the area under the plasma concentration time curve, the peak plasma concentration and the absolute bioavailability of the liquisolid and the commercial tablets were observed.
Hence due to above reasons liquisolid technique is most efficient and novel approach for solubility enhancement. This angle is known as angle of slide. Mainly liquisolid technique is used for drug candidates comes under class II and class IV drugs. Several methods are studied for increasing dissolution performance and bioavailability including micronization, Nanonisation, complexation with cyclodextrins, solid dispersion, self emulsifying system, liquisolid systems etc. In general amorphous are more soluble than metastable polymorphs, anhydrates are more soluble than hydrates and solvates are more soluble than non-solvates.
The powder was allowed to flow through the funnel freely into the surface.
The beta and gamma cyclodextrins and their several derivatives have unique ability to form molecular inclusion complexes with hydrophobic drugs having poor aqueous solubility. In order technkque ensure the suitability of the selected excipients, Fourier Transform Infra Red Spectroscopy, Differential scanning Calorimetry, X-ray Diffraction and Scanning Electron Microscope studies are to be performed. This liquisolid technology is a promising tool for the enhancement of drug release of poorly soluble drugs.
Effect of Ceolus KG on the dissolution rate of fenofibrate liquisolid tablets: Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution-NonCommercial 3.
The first two groups may exist or be produced by changing drug solutions and drug suspensions while the third is produced from the formulation of liquid drugs into liquisolid systems.
The concept behind this approach is adsorption and absorption both.
Pharmaceutical applications of liquisolid technique
This procedure involves the fixed height of each liquisolid powder substrate with prepared and fixed weight. Several studies have been carried out to increase the dissolution rate of drugs by decreasing the particle size, by creating nanoparticles and microparticles.
Thus, a constant plasma level will be reached, which is maintained throughout the dosing interval. Effect of some commercial grades of microcrystalline cellulose on flowability, compressibility and dissolution profile of piroxicam liquisolid compacts. Demerits of liquisolid techniques: Liquisolid tablet contact angle is less than that of direct compressed tablets.
The poor dissolution characteristics of water insoluble drugs are a major challenge for pharmaceutical science. On other hand, in some cases, the drug diffusion through the primary particles may be rapid and might lead to overwhelming solubility- wise of the stagnant dissolution layers with drug.
Polymorphic changes of the drug are important factors that may affect the dissolution rate and bio availability.
Liquisolid systems and methods of preparing same. By using the Liquisolid technique, sustained liquidolid delivery systems were developed for the water soluble drugs in which hydrophobic non-volatile solvents are used as vehicles.
Pharmaceutical applications of liquisolid technique
The following parameters describe a measure of the flow teechnique of liquisolid systems that will be selected and compressed into tablets. In-vivo evaluation of hydrochlorothiazide liquisolid tablet in beagles dogs. Non-volatile solvent present in the liquisolid system facilitates wetting of drug particles by decreasing interfacial tension between dissolution medium and tablet surface. Water- insoluble or poorly water soluble drugs may be expected to have increased dissolution rate properties as well as improved bioavailability.
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The enhanced rate of indomethacin dissolution from liquisolid tablets was probably due to an increase in wetting properties and surface area of drug particles available for dissolution. By measuring the height and diameter of the techniquw drop on the Spireas et al. D is the diffusion coefficient of the drug molecules transported through it, S is the surface area of the drug available for dissolution, C is the drug concentration in the bulk of the dissolving medium, Cs is the saturation solution of the drug in the dissolution medium.
Salts have improved solubility and dissolution as compared to the original drug. Once drug particles solubilised in SCFs, they may be greatly recrystallised at greatly reduced particle sizes.
Ammar Said Suliman, Rosaleen J. Tiong N et al. According to this equation, stagnant diffusion layer thickness is h, and formed by the dissolving liquid around the drug particles.
From this equation, dissolution rate is directly proportional not only to the concentration gradient of the drug in the stagnant diffusion layer Cs- Techniqudbut also to its surface area S available for dissolution. This saturated solution is prepared by adding excess amount of drug in non solvent. Absence of constructive specific peaks of the drug in the liquisolid compacts in X-ray diffractogram specify that drug has almost entirely converted from crystalline to amorphous or solubilised form.
Production hechnique liquisolid system is similar to that of conventional tablets. This free flowing powder is than subjected to Preformulation studies like Fourier transformed infrared spectroscopy, differential scanning Calorimetry for compatibility studiesangle of slide, flow properties, solubility studies, calculation of liquid load tevhnique potential, liquid load factor etc.
Various methods used for enhancing solubility and thus bioavailability of drug are: