Microemulsions drugs

Djordjevic, L., Primorac, M., Stupar, M. and Krajisnik, D. (2004) Characterization of capry-locaproyl macrogolglycerides based microemulsion drug delivery vehicles for an Amphiphilic drug. Int. J. Pharm., 271, 11-19. 

Subramanian, N., Ghosal, S.K. and Moulik, S.P. (2005) Enhanced in vitro percutaneous absorption and in vivo anti-inflammatory effect of a selective cyclooxygenase inhibitor using microemulsion. Drug Dev. Ind. Pharm., 31, 405-416. 

Ghosh, P.K., Majithiya, R.J., Umrethia, M.L. andMurthy, R.S.R. (2006) Design and development of microemulsion drug delivery system of acyclovir for improvement of oral bioavailability. AAPS Pharmscitech, 7, 77. 

Shevachman M, Garti N, Shani A, and Sintov AC. (2008). Enhanced percutaneous permeability of diclofenac using a new U-type dilutable microemulsion. Drug Development and Industrial Pharmacy, 34, 403-412. 

Djordjevic L, Primorac M, Stupar M, Krajisnik D. Characterization of caprylocaproyl macrogolglyc-erides based microemulsion drug delivery vehicles for an amphiphilic drug. International Journal of Pharmaceutics. 2004 271(1) 11-19. 

Nanosize particles of polyacrylic acid were synthesized in w/o microemulsions using azobisisobutyronitrile as lipophilic radical initiator, which were considered suitable for encapsulation of peptides and other hydrophilic drugs [195],... 

Percolated microemulsions composed of biocompatible substances, such as some lecithin-based organogels, have been considered interesting vehicles for the delivery of drugs [288],... 

Agatonovic-Kustrin S, Glass BD, Wisch MH, Alany RG. Prediction of a stable microemulsion formulation for the oral delivery of a combination of antitubercu-lar drugs using ANN technology. Pharm Res 2003 20 1760-5. 

Tenjarla, S., Microemulsions an overview and pharmaceutical applications, Crit. Rev. Then Drug, 16, 461, 1999. 

A., Tripodi, V. P., Sdoscia, S. L, Carducd, C. N. Relation between retention fadors of immunosuppressive drugs in microemulsion electrokinetic chromatography with biosurfactants and octanol-water partition coeffidents. 

Ornskov, E.,. Gottfries, M. Erickson, S. Folestad. Experimental modelling of drug membrane permeability by capillary electrophoresis using liposomes, micelles and microemulsions./. Pharm. Pharmacol. 2005, 57, 435 2. 

The majority of RDC studies have concentrated on the measurement of solute transfer resistances, in particular, focusing on their relevance as model systems for drug transfer across skin [14,39-41]. In these studies, isopropyl myristate is commonly used as a solvent, since it is considered to serve as a model compound for skin lipids. However, it has since been reported that the true interfacial kinetics cannot be resolved with the RDC due to the severe mass transport limitations inherent in the technique [15]. The RDC has also been used to study more complicated interfacial processes such as kinetics in a microemulsion system [42], where one of the compartments contains an emulsion. 

HN Bhargava, A Narurkar, LM Lieb. Using microemulsions for drug delivery. Pharm Tech 11 46-54,1987. 

Given such difficulties, it is not unsurprising that bioavailabilities below 1 per cent are often recorded in the context of oral biopharmaceutical drug delivery. Strategies pursued to improve bioavailability include physically protecting the drug via encapsulation and formulation as microemulsions/microparticulates, as well as inclusion of protease inhibitors and permeability... 

Araya H, Tomita M, Hayashi M (2006) The novel formulation design of self-emulsifying drug delivery systems (SEDDS) type O/W microemulsion III The permeation mechanism of a poorly water soluble drug entrapped O/W microemulsion in rat isolated intestinal membrane by the Ussing chamber method. Drug Metab Pharmacokinet 21 45-53. 

The procedure chosen for the preparation of lipid complexes of AmB was nanoprecipitation. This procedure has been developed in our laboratory for a number of years and can be applied to the formulation of a number of different colloidal systems liposomes, microemulsions, polymeric nanoparticles (nanospheres and nanocapsules), complexes, and pure drug particles (14-16). Briefly, the substances of interest are dissolved in a solvent A and this solution is poured into a nonsolvent B of the substance that is miscible with the solvent A. As the solvent diffuses, the dissolved material is stranded as small particles, typically 100 to 400 nm in diameter. The solvent is usually an alcohol, acetone, or tetrahydrofuran and the nonsolvent A is usually water or aqueous buffer, with or without a hydrophilic surfactant to improve colloid stability after formation. Solvent A can be removed by evaporation under vacuum, which can also be used to concentrate the suspension. The concentration of the substance of interest in the organic solvent and the proportions of the two solvents are the main parameters influencing the final size of the particles. For liposomes, this method is similar to the ethanol injection technique proposed by Batzii and Korn in 1973 (17), which is however limited to 40 mM of lipids in ethanol and 10% of ethanol in final aqueous suspension. 

Depending on the drug substance properties and the medical indication, the appropriate formulation is chosen. Drug substances which have a good solubility may be formulated in a simple tablet formulation, while drug substance candidates with low solubilities require special delivery systems like microemulsion formulations. 

After a short introduction into the relevance of Impurity profiling for regulatory authorities, public health, and the pharmaceutical industry, an overview is presented based on the various modes of capillary electrophoresis that have been used in drug impurity analysis. The applications of capillary zone electrophoresis, non-aqueous capillary electrophoresis, micellar electrokinetic capillary chromatography, microemulsion electrokinetic capillary chromatography, capillary gel electrophoresis, and capillary electrochromatography are presented consecutively. 

In recent years, much of the research work in the pharmaceutical sciences was focused on the development of effective vehicle systems, such as micelles, microemulsions, and liposomes, for drugs that are critical with respect to bioavailability. Knowledge of this subject is a prerequisite to developing vehicle systems for special administration routes, such as dermal, transdermal, intravenous, and nasal. 

In pharmaceutics, therefore, simple and effective methods and procedures are needed to characterize the interactions of drugs with pharmaceutical excipients (polysaccharides, cyclodextrins, etc.) and vehicle systems (micelles, microemulsions, and liposomes) in order to optimize the load of vehicle systems with the drugs. 

Part II starts with the possibilities of ACE for characterizing the relevant physicochemical properties of drugs such as lipophilicity/hydrophilicity as well as thermodynamic parameters such as enthalpy of solubilization. This part also characterizes interactions between pharmaceutical excipients such as amphiphilic substances (below CMC) and cyclodextrins, which are of interest for influencing the bioavailability of drugs from pharmaceutical formulations. The same holds for interactions of drugs with pharmaceutical vehicle systems such as micelles, microemulsions, and liposomes. 

Affinity of Drugs to Pharmaceutical Vehicle Systems Microemulsions... 

The interactions between drugs and proteins such as albumin, acidic glycoprotein, and other possible target proteins are discussed in specific chapters. Some important applications of ACE concerning drug carrier systems (simple and mixed micelles, microemulsions, liposomes) are covered in subsequent chapters of this book. 

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