Development, validation and application of LC-MS/MS method for quantification of amino acids, kynurenine and serotonin in human plasma.

Altered serotonergic neurotransmission is a key factor in several neurologic and psychiatric disorders such as migraine. Human and animal studies suggest that chronically low interictal serotonin levels of plasma and brain may facilitate increased activity of the trigeminovascular pathway, and may contribute to development of repeated migraine attacks. However, brain serotonin synthesis is affected by the concentration of tryptophan, its metabolites and a number of amino acids. In this work a simple and robust LC-MS/MS method for the quantitative determination of valine, leucine, isoleucine, phenylalanine, tyrosine, tryptophan, serotonin and kynurenine in human plasma has been developed and validated. Sample preparation was achieved by protein precipitation, using trifluoroacetic acid. Chromatographic separation was carried out on a Supelco Ascentis® Express C18 column (3.0 mm i.d. × 150 mm, 2.7 µm) equipped with an Agilent Zorbax Eclipse XDB C8 guard-column under isocratic conditions at a flow rate of 0.4 mL/min, over a 6.5 min run time. Mobile phase was 0.2% trifluoroacetic acid - acetonitrile (85:15, v/v). The eight analytes and two internal standards were ionized by positive electrospray ionization and detected in multiple reaction monitoring mode. A "fit-for-purpose" validation approach was adopted using surrogate matrix for the preparation of calibration samples. The calibration curves of all analytes showed excellent linearities with a correlation coefficient (r2) of 0.998 or better. Spiked surrogate matrix samples and pooled human plasma were used as quality control samples. Intra-day and inter-day precisions were less than 11.8% and 14.3%, and accuracies were within the ranges of 87.4-114.3% and 87.7-113.3%, respectively. Stability of the components in standard solutions, surrogate matrix, pooled plasma and processed samples were found to be acceptable under all relevant conditions. No significant carryover effect was observed. The surrogate matrix behaved parallel to human plasma when assessed by standard addition method and diluting the authentic matrix with surrogate matrix. The method was successfully applied for analysis of 800 human plasma samples to support a clinical study.

Kinetics of dopamine release from poly(aspartamide)-based prodrugs.

Preparation of novel biocompatible and biodegradable polymer-based prodrugs that can be applied in complex drug delivery systems is one of the most researched fields in pharmaceutics. The kinetics of the drug release strongly depends on the physicochemical parameters of prodrugs as well as environmental properties, therefore precise kinetical description is crucial to design the appropriate polymer prodrug formula. The aim of the present study was to investigate the dopamine release from different poly(aspartamide) based dopamine drug conjugates in different environments and to work out a kinetic description which can be extended to describe drug release in similar systems. Poly(aspartamide) was conjugated with different amounts of dopamine. In order to alter the solubility of the conjugates, 2-aminoethanol was also grafted to the main chain. Chemical structure as well as physical properties such as solubility, lipophilicity measurements and thermogravimetric analysis has been carried out. Kinetics of dopamine release from the macromolecular prodrugs which has good water solubility has been studied and compared in different environments (phosphate buffer, Bromelain and α-Chymotrypsin). It was found that the kinetics of release in those solutions can be satisfactorily described by first order reaction rate. For poorly-soluble conjugates, the release of dopamine was considered as a result of coupling of diffusion and chemical reaction. Besides the time dependence of dopamine cleavage, a practical quantity, the half-life of the release of loading capacity has been introduced and evaluated. It was found, that dopamine containing macromolecular prodrugs exhibit prolonged release kinetics and the quantitative description of the kinetics, including the most important physical parameters provides a solid base for future pharmaceutical and medical studies. STATEMENT OF SIGNIFICANCE: Poly(aspartamide) based polymer-drug conjugates are promising for controlled and prolonged drug delivery due to their biocompatibility and biodegradability. In this study different poly(aspartamide) based dopamine conjugates were synthesized which can protect dopamine from deactivation in the human body. Since there is no satisfying kinetics description for drug release from covalent polymer-drug conjugates in the literature, dopamine release was investigated in different environments and a complete kinetical description was worked out. This study demonstrates that poly(aspartamide) is able to protect conjugated dopamine from deactivation and provide prolonged release in alkaline pH as well as in the presence of different enzymes. Furthermore, detailed kinetical descriptions were demonstrated which can be used in case of other covalent polymer-drug conjugates.

Baicalin is a substrate of OATP2B1 and OATP1B3.

The use and significance of baicalin, the main bioactive component found in Radix Scutellaria, have been on the rise due to its interesting pharmacological properties. Baicalin, a low passive permeability compound, is directly absorbed from the upper intestine and its hepatic elimination is dominant. However, interaction but no transport studies have implicated organic anion­transporting polypeptides in its cellular uptake. By using mammalian cells stably expressing the uptake transporters of interest, we are showing that baicalin is a potent substrate of Organic anion­transporting polypeptide 2B1 (OATP2B1) and less potent substrate of OATP1B3. OATP2B1 and OATP1B3 transport baicalin and may play a role in the hepatic uptake of baicalin formed in the intestine.

Study on the Pulmonary Delivery System of Apigenin-Loaded Albumin Nanocarriers with Antioxidant Activity.

BACKGROUND: Respiratory diseases are mainly derived from acute and chronic inflammation of the alveoli and bronchi. The pathophysiological mechanisms of pulmonary inflammation mainly arise from oxidative damage that could ultimately lead to acute lung injury. Apigenin (Api) is a natural polyphenol with prominent antioxidant and anti-inflammatory properties in the lung. Inhalable formulations that consist of nanoparticles (NPs) have several advantages over other administration routes, and therefore, this study investigated the application of apigenin-loaded bovine serum albumin nanoparticles (BSA-Api-NPs) for pulmonary delivery. METHODS: Dry powder formulations of BSA-Api-NPs were prepared by spray drying and characterized by laser diffraction particle sizing, scanning electron microscopy, differential scanning calorimetry, and powder X-ray diffraction. The influence of dispersibility enhancers (lactose monohydrate and l-leucine) on the in vitro aerosol deposition using a next-generation impactor was investigated in comparison to excipient-free formulation. The dissolution of Api was determined in simulated lung fluid by using the Franz cell apparatus. The antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH⋅) free radical scavenging assay. RESULTS: The encapsulation efficiency and the drug loading were measured to be 82.61% ± 4.56% and 7.51% ± 0.415%. The optimized spray drying conditions were suitable to produce particles with low residual moisture content. The spray-dried BSA-Api-NPs possessed good aerodynamic properties due to small and wrinkled particles with low mass median aerodynamic diameter, high emitted dose, and fine particle fraction. The aerodynamic properties were enhanced by leucine and decreased by lactose, however, the dissolution was reversely affected. The DPPH⋅ assay confirmed that the antioxidant activity of encapsulated Api was preserved. CONCLUSION: This study provides evidence to support that albumin nanoparticles are suitable carriers of Api and the use of traditional or novel excipients should be taken into consideration. The developed BSA-Api-NPs are a novel delivery system against lung injury with potential antioxidant activity.

Physicochemical analysis in the evaluation of reconstituted dry emulsion tablets.

The aim of this study was to characterize the formation of emulsions by droplet size analysis and turbidimetry during reconstitution from a solid dosage form, namely from dry emulsion systems, which carry an oil phase for poorly soluble active ingredients. For the dry emulsion systems tablets were prepared either from oil-in-water systems using a freeze-drying process or through direct compression containing the same oil and excipients. The ratios of oil to emulgents and oil to xanthan gum were equal in both methods. In the preparation methods applied, mannitol, erythritol and lactose were used as excipients and mannitol was found to be the most effective excipient based on droplet size reconstitution, turbidimetry and physical properties. Quality control involved testing the physical properties of tablets and characterizing the reconstituted emulsions.

Development and characterization of the voriconazole loaded lipid-based nanoparticles.

The number of topical fungal infections is growing, mostly owing to immunosuppressive therapy. Several topical fungal infections, such as eye mycoses, can be treated by local administration of antimycotic drugs. One major group of the antifungal agents is triazole, such as voriconazole (VCZ), which is used as the first line treatment of aspergillosis. A disadvantage of VCZ is its low water solubility making the drug difficult to administer in a liquid preparation. The lipid-based nanoparticles (LNP) have attracted increasing attention due to their advantageous properties. Contrarily to the conventional carrier systems, LNP can improve the poor solubility of topically used drugs, such as VCZ. Therefore, LNP represents promising alternatives to traditional carrier systems. The aim of the study was to formulate VCZ loaded lipid-based nanoparticles (VCZ-LNP) by high pressure homogenization (HPH). The developed LNPs were characterized by particle size analysis, IR spectroscopy, differential scanning calorimetry, dialysis test and antifungal efficacy studies. The particle size of the optimized nanoparticles from the selected lipid base, Witepsol® W35, was 182±4.1nm after five cycles of homogenization at 600bar. The antifungal study confirmed that the optimized VCZ-LNP inhibited the fungus reproduction.

Controlled Release Oral Delivery of Apigenin Containing Pellets with Antioxidant Activity.

BACKGROUND: Drug delivery of phytochemicals has gained interest recently due to their remarkable health effects. Apigenin, a plant flavonoid, has antioxidant, anti-inflammatory and anticancer activities but its delivery is challenging. It could be absorbed through the whole intestine, however, it has poor bioavailability due to its low aqueous solubility. In Europe, the daily intake was estimated to be as low as 3 ± 1 mg. Pellets offer several advantages such as improved bioavailability and various resultant drug release profiles can be obtained by simply mixing pellets with different coatings. OBJECTIVE: The objective of our study was to develop a carrier system containing 20 mg apigenin thus enhancing intake and to offer reduction of oxidative stress which can cause inflammation in the intestine. METHOD: The apigenin powder was dispersed in aqueous solution of binding material and layered onto the inert cores in a fluidized bed apparatus. The layered cores were further coated with enteric polymers and the process parameters were optimized. RESULTS: The prepared pellets met with the requirements and have good physical characteristic. 10% (w/w) Eudragit® L was suitable for enteric coating with a complete release at pH 6.8 within 1 hour. 15% (w/w) Eudragit® FS coating ensured acid resistance ability and colonic delivery. The therapeutic efficiency was confirmed with antioxidant activity measurement by using DPPH* assay. CONCLUSION: Enteric coated spheres allow targeted delivery into the intestine and colon thus reaching the main absorption site. Pellets were proved to be an optimal delivery system for apigenin thus providing enhanced apigenin intake.

Development of oral site-specific pellets containing flavonoid extract with antioxidant activity.

Herbal medicines are recognized as an effective treatment of common diseases, mainly associated with oxidative stress. Therefore developing drug delivery systems of these biological active ingredients are gaining interest. Parsley (Petroselinum crispum L.) is a well-known culinary herb and its leaf contains high amount of apigenin, therefore it is suitable as a natural source of this flavonoid. Apigenin possess many health effects such as antioxidant, anti-inflammatory and anticancer activities. Unfortunately, these benefits are limited due to the low water solubility and bioavailability, it was recently classified as BCS II group compound. Therefore the aim of this study was to develop a carrier system for Petroselinum crispum extract, containing high amount of apigenin. Microcrystalline cellulose inert pellet cores were chosen and enteric coatings were applied. The produced multiparticulates had spherical shape, narrow size distribution and low moisture content. 10% (w/w) Eudragit® L 30 D-55 and 15% (w/w) Eudragit® FS 30 D coating was adequate for the modified release in vitro. The layered pellets demonstrated antioxidant activity. It was concluded that development of oral site-specific pellets containing flavonoid extract successful and the therapeutic effectiveness could be hypothesized.

Development and characterization of voriconazole loaded nanoparticles for parenteral delivery.

Human serum albumin (HSA) has attracted the most attention in the last decades as a new nanocarrier system of active pharmaceutical ingredients (API) due to its biocompatibility and high binding capacity to hydrophobic drugs. Voriconazole (VCZ), an antifungal agent with low water solubility, was selected to produce albumin based nanoparticles using nanoparticle albumin-bound technology (nab™-technology). Aim of our study was to study the development process of VCZ-loaded nanoparticles for parenteral drug delivery, such as homogenizing pressure, homogenizing cycle number and drug loading capacity. The main characters of nanoparticles such as particle size distribution and polydispersity index (PDI) were determined by dynamic light scattering. Six homogenization cycles at 1800bar were ensured the acceptable PDI value (lower than 0.3) of the VCZ content nanoparticles. Optimized formulation process produced 81.2±1nm average particle size which meets the requirements of intravenous administration. Furthermore, the encapsulated concentration of VCZ was 69.7±4.2% and the water solubility was over 2 times greater than the API itself which were determined by the developed HPLC method. The in vivo release behavior can be predicted from our applied in vitro dissolution study. Almost 50% of VCZ was liberated from the nanoparticles in the first 60min.

Multiple ABC Transporters Efflux Baicalin.

Baicalein, the aglycone formed by hydrolysis of baicalin in the intestine, is well absorbed by passive diffusion but subjected to extensive intestinal glucuronidation. Efflux of baicalin, the low passive permeability glucuronide of baicalein from enterocytes, likely depends on a carrier-mediated transport. The present study was designed to explore potential drug-herb interaction by investigating the inhibitory effect of baicalin on the transport of reporter substrates by transporters and to identify the transporters responsible for the efflux of baicalin from enterocytes and hepatocytes. The interaction of baicalin with specific ABC transporters was studied using membranes from cells overexpressing human BCRP, MDR1, MRP2, MRP3 and MRP4. Baicalin was tested for its potential to inhibit vesicular transport by these transporters. The transport of baicalin by the selected transporters was also investigated. Transport by BCRP, MRP3 and MRP4 was inhibited by baicalin with an IC50 of 3.41 ± 1.83 µM, 14.01 ± 2.51 µM and 14.39 ± 5.69 µM respectively. Inhibition of MDR1 (IC50 = 94.84 ± 31.10 µM) and MRP2 (IC50 = 210.13 ± 110.49 µM) was less potent. MRP2 and BCRP are the apical transporters of baicalin that may mediate luminal efflux in enterocytes and biliary efflux in hepatocytes. The basolateral efflux of baicalin is likely mediated by MRP3 and MRP4 both in enterocytes and hepatocytes. Via inhibition of transport by ABC transporters, baicalin could interfere with the absorption and disposition of drugs.

Unexpected retention behavior of baicalin: Hydrophilic interaction like properties of a reversed-phase column.

The original aim of this study was to develop a method for the determination of baicalin from membrane vesicles. The unconventional chromatographic separation ("inverse gradient elution" on a reversed phase column) was due to a lucky chance, which is detailed and discussed in this study. The validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method is proved to be sensitive, rapid and selective. Chromatographic separation was performed on a Zorbax SB-C8 column (250 mm × 4.6 mm, i.d.; 5 µm) with 0.1% formic acid in water and methanol by linear gradient elution. Quantification of baicalin was determined by multiple reaction monitoring (MRM) mode using electrospray ionization (ESI). The calibration curve was linear (r = 0.9987) over the concentration range from 1 to 1000 nM. The coefficient of variation and relative error of baicalin for intra- and inter-assay at three quality control (QC) levels were 2.0-10.2% and -6.1 to 6.7%, respectively. The lower limit of quantification (LLOQ) for baicalin was 1 nM (0.446 ng/ml), without preconcentration of the sample. This method was subsequently applied to vesicular transport assays of baicalin in membrane vesicles successfully. The developed method can open up new area of research in the chromatographic separation of flavonoids and their glucuronides.

The similarity question for biologicals and non-biological complex drugs.

For small - low molecular weight - molecule medicines a robust regulatory system has evolved over the years. This system guarantees high and constant quality of our (generic) medicines. Pharmaceutical equivalence and bioequivalence assessment are the pillars under that system. But there are complex medicines where the question of equivalence is more challenging to answer. For biologicals the paradigm of similarity rather than equality (the emergence of 'biosimilars') was developed in the past decade. This has been a program where an evolutionary, science based approach has been chosen by the frontrunner regulatory body, the EMA, with a 'learn and confirm' character. In addition, there is another group of complex drugs, the non-biological complex drugs, NBCDs, where the generic paradigm can be challenged as well. The NBCDs are defined as: 1. consisting of a complex multitude of closely related structures; 2. the entire multitude is the active pharmaceutical ingredient; 3. the properties cannot be fully characterized by physicochemical analysis and 4. the consistent, tightly controlled manufacturing process is fundamental to reproduce the product. NBCDs encompass product families such as the glatiramoids, liposomes, iron-carbohydrate colloids and many candidates of the group of the upcoming nanoparticulate systems. Following the main principles of regulatory pathways for biologicals (with appropriate product-by-product adjustments), instead of that for small molecules, would be the more logical strategy for these NBCDs. The status and outstanding regulatory issues for biosimilars and NBCD-similars/follow on versions were discussed at a conference in Budapest, Hungary (October 2014) and this commentary touches upon the issues brought up in the presentations, deliberations and conclusions.

Supramolecular elucidation of the quality attributes of microcrystalline cellulose and isomalt composite pellet cores.

The major objective of this study was to disclose the relationships between the physical quality attributes and supramolecular structure of novel composite pellet cores containing microcrystalline cellulose (MCC) and isomalt in different ratios. The novel composite pellet cores were manufactured by an extrusion/spheronisation process. The micro or supramolecular structure of pellets was tracked by positron annihilation lifetime spectroscopy (PALS) based on the o-Ps lifetime values. The results indicate a correlation between the examined macro and microstructural properties of the inert cores. The higher free volume holes indicated by the higher o-Ps lifetime values resulted in a more mobile micro- and supramolecular structure of MCC cores thus increasing the plastic deformation and the tensile strength of the cores. A physical interaction was found between the microcrystalline cellulose and isomalt which supports the osmotic effect of the water soluble sugar alcohol in the composite pellet cores regarding drug release.

Liposomes for topical use: a physico-chemical comparison of vesicles prepared from egg or soy lecithin.

Developments in nanotechnology and in the formulation of liposomal systems provide the opportunity for cosmetic dermatology to design novel delivery systems. Determination of their physico-chemical parameters has importance when developing a nano-delivery system. The present study highlights some technological aspects/characteristics of liposomes formulated from egg or soy lecithins for topical use. Alterations in the pH, viscosity, surface tension, and microscopic/macroscopic appearance of these vesicular systems were investigated. The chemical composition of the two types of lecithin was checked by mass spectrometry. Caffeine, as a model molecule, was encapsulated into multilamellar vesicles prepared from the two types of lecithin: then zeta potential, membrane fluidity, and encapsulation efficiency were compared. According to our observations, samples prepared from the two lecithins altered the pH in opposite directions: egg lecithin increased it while soy lecithin decreased it with increased lipid concentration. Our EPR spectroscopic results showed that the binding of caffeine did not change the membrane fluidity in the temperature range of possible topical use (measured between 2 and 50 °C). Combining our results on encapsulation efficiency for caffeine (about 30% for both lecithins) with those on membrane fluidity data, we concluded that the interaction of caffeine with the liposomal membrane does not change the rotational motion of the lipid molecules close to the head group region. In conclusion, topical use of egg lecithin for liposomal formulations can be preferred if there are no differences in the physico-chemical properties due to the encapsulated drugs, because the physiological effects of egg lecithin vesicles on skin are significantly better than that of soy lecithin liposomes.

[Importance of drug interactions with smoking in modern drug research]. / Dohányzás-gyógyszer interakciók jelentosége a korszeru gyógyszerkutatásban.

Drug interaction is a process during which a drug's fate in the body or its pharmacological properties are altered by an influencing factor. The extent of the drug interaction's effect can vary. The interaction could result from the modulation by another drug, food, alcohol, caffeine, narcotics, a drug influencing absorption or smoking. Moreover, transporter interactions with smoking could also have a major impact on many drug's efficacy. Clinically relevant drug interactions with smoking were classified in terms of their effect: pharmacokinetic, pharmacodynamic and transporter interactions. Policyclic aromatic carbohydrates, found in cigarette smoke, have enzyme inducing properties. The interaction affects mainly the hepatic isoenzyme CYP1A2. Interactions caused by smoking have an effect on all drugs being substrates of and therefore metabolised by CYP1A2. Pharmacokinetic alteration can also occur during the absorption, distribution and elimination process. The pharmacodynamic interactions are mainly caused by the effects of nicotine, a cigarette smoke component. Through interactions, smoking could also modify the activity of transporter proteins, altering this way the ADME properties of many drugs. Since smoking is one of the deadliest artefact in the history of human civilisation, identifying drug interactions with smoking is the physician's and pharmacist's major responsibility and task. Moreover, it is necessary to identify the patient's smoking habits during a medical treatment. This review aims to investigate the main types of drug interactions (PK/PD), identify factors influencing the activity of CYP enzymes and transporters, and also summarize the mechanisms of the most important drug interactions with smoking and their clinically relevant consequences (Table II-VI.). Drugs, with effects somehow altered by smoking-interactions, have been studied.

Natural oils and waxes: studies on stick bases.

The objective of the present article was to examine the role of origin and quantity of selected natural oils and waxes in the determination of the thermal properties and hardness of stick bases. The natural oils and waxes selected for the study were sunflower, castor, jojoba, and coconut oils. The selected waxes were yellow beeswax, candelilla wax, and carnauba wax. The hardness of the formulations is a critical parameter from the aspect of their application. Hardness was characterized by the measurement of compression strength along with the softening point, the drop point, and differential scanning calorimetry (DSC). It can be concluded that coconut oil, jojoba oil, and carnauba wax have the greatest influence on the thermal parameters of stick bases.

[Pharmaceutical and formulation aspects of Petroselinum crispum extract]. / Petroselinum crispum kivonatának gyógyszerészeti vonatkozásai és formulálási lehetoségei.

Parsley (Petroselinum crispum L.) is a very popular spice and vegetable in Europe, it is widely spread and easy to grow. It's herb and fruits are known to be diuretic, smooth muscle relaxant and hepatoprotective. The most important identified active ingredients are flavonoids, cumarins and vitamin C. Apigenin and its glycosides are the main flavonoids in parsley, it can be found relatively large amounts in the leaves. The bioactive flavonoid apigenin has antiinflammatory, antioxidant and anticancer activities. The objectives of this study were the preparation and detemination of the apigenin content of the parsley extract and the formulation using inert pellets by layering the apigenin in fluid-bed process.

Dissolution profile of novel composite pellet cores based on different ratios of microcrystalline cellulose and isomalt.

There is a growing interest towards the application of inert cores as starting materials for pharmaceutical pellet manufacturing. They serve as alternatives to develop and adapt a relatively simple manufacturing technology compared with an extrusion/spheronisation process. The major objective of this study was to investigate the effect of the compositions of core materials on the drug release profile. Pure microcrystalline cellulose (MCC), isomalt and different types of novel composite MCC-isomalt cores were layered with model drug (sodium diclofenac) and were coated with acrylic polymer. The effect of the osmolality in the gastrointestinal tract was simulated using glucose as osmotically active agent during in vitro dissolution tests. The results demonstrated the dependence of drug dissolution profile on the ratio of MCC and isomalt in the core and the influence of osmotic properties of the dissolution medium. Isomalt used in the composite core was able to decrease the vulnerability of the dissolution kinetics to the changes in the osmotic environment.

Improved therapeutic entities derived from known generics as an unexplored source of innovative drug products.

With a New Drug Application (NDA) innovative drug therapies are reaching the market in a specific dosage form for one or more clinically proven indications of which after expiration of the patent or the data exclusivity copies are launched using Abbreviated New Drug Applications (ANDA). Advanced therapies that emerged from launched molecules during their product life-cycle have gained considerable attention as clinical practice provides evidence for additional therapeutic values, patient centric delivery systems show improved therapeutic outcomes or emerging technologies offer efficiency gains in manufacturing or access to emerging markets. The USA and European regulatory framework has set reasonable regulations in place for these "Supergenerics" or "hybrid" applications. While these regulations are relatively recent the pharmaceutical industry is just starting to use this route for their product development and life-cycle management. From a clinical perspective the potential for advanced product development have been demonstrated. Yet, there is still a lag of common understanding between the different stakeholders regarding the development, application process and commercial incentive in developing enhanced therapeutic entities based on existing drug products for the market.

Composition optimization and stability testing of a parenteral antifungal solution based on a ternary solvent system.

An intravenous solution is a dosage forms intended for administration into the bloodstream. This route is the most rapid and the most bioavailable method of getting drugs into systemic circulation, and therefore it is also the most liable to cause adverse effects. In order to reduce the possibility of side effects and to ensure adequate clinical dosage of the formulation, the primarily formulated composition should be optimized. It is also important that the composition should retain its therapeutic effectiveness and safety throughout the shelf-life of the product. This paper focuses on the optimization and stability testing of a parenteral solution containing miconazole and ketoconazole solubilized with a ternary solvent system as model drugs. Optimization of the solvent system was performed based on assessing the risk/benefit ratio of the composition and its properties upon dilution. Stability tests were conducted based on the EMEA (European Medicines Agency) "guideline on stability testing: stability testing of existing active substances and related finished products". Experiments show that both the amount of co-solvent and surface active agent of the solvent system could substantially be reduced, while still maintaining adequate solubilizing power. It is also shown that the choice of various containers affects the stability of the compositions. It was concluded that by assessing the risk/benefit ratio of solubilizing power versus toxicity, the concentration of excipients could be considerably decreased while still showing a powerful solubilizing effect. It was also shown that a pharmaceutically acceptable shelf-life could be assigned to the composition, indicating good long-term stability.