HLB Value Research Articles

Optimization for Production Tert-Butyl Oleyl Glycoside Nonioic Surfactant Using Response Surface Methodology

The development of surfactant production process strongly influenced by the potential use of raw materials and products that are environmentally friendly. For raw materials such as surfactants are carbohydrate-based material utilization example, glucose, which is reacted with tert-butanol, to form tert-butyl glycoside (TBG), then TBG can be esterified with oleic acid forming surfactant tert-butyl oleyl glycoside (TBOG). This study aims to obtain the optimum conditions TBOG production process of esterification reactions TBG and oleic acid catalyst the para toluene sulfonic acid using response surface method to reach optimum yield TBOG. The independent variable used is the mole ratio of TBG with oleic acid, percent of the catalyst and a temperature. Optimization results obtained optimum conditions of mole ratios of 1: 4.096; 2.33 percent of the catalyst and the temperature of 96.04 °C with a TBOG yield of 92.46%, with a TBOG content of 91.72 %. Based on the HLB value of the surfactant TBOG is 3.87, then these surfactants can be used as an emulsifier of water-in-oil.

Amphiphilic properties of alkoxyoligoethyleneglycol methacrylates and copolymers based on them

Based on the data on the distribution of alkoxyoligo(ethyleneglycol) methacrylates in the water-hexane system, the HLB values of the macromonomers are determined. A good correlation between the temperatures of phase transitions of copolymers of alkoxyoligo(ethyleneglycol) methacrylates in aqueous solutions and calculated HLB values of the original macromonomers was shown.

Fatty acid ester surfactants derived from raffinose: Synthesis, characterization and structure-property profiles

HypothesisThe development of functional and nutritional surfactants for the food industry remains a subject of great interest. Herein, therefore, we report on the design and synthesis of novel trisaccharide (raffinose) monoester-based surfactants in the expectation that they would display functional properties superior to certain disaccharide-based, commercially-deployed emulsifiers and thus have potential for industrial applications. ExperimentsThe title esters were prepared by enzymatic methods and their properties as surfactants evaluated through determination of their HLB values, water solubilities, CMCs, foamabilities and foaming stabilities as well as through investigation of their impacts on the stability of oil-in-water emulsions over a range of storage times and under certain other conditions. FindingsThe emulsifying properties of 6-O-acylraffinose esters are dictated, in large part, by the length of the associated alkyl chains. The results of storage and environmental stress experiments revealed that the increasing length of alkyl chains enhances the stability of the derived emulsions. All the raffinose ester-stabilized oil-in-water emulsions displayed stratification effects under strongly acidic conditions (pH ≤ 4) or at high ionic strength (≥300 mM) while possessing reasonable resistance to variations in temperature. As such, a number of the raffinose monoesters showed greater stability to environmental stress than their commercially-deployed and sucrose-based counterparts. The structure-property profiles established through the present study provide a definitive guide for the development of raffinose esters as novel emulsifiers, particularly in the food industry.

Development of Nanoemulsions Containing Coconut Oil with Mixed Emulsifiers: Effect of Mixing Speed on Physical Properties

Recently, coconut oil has become an attractive natural material consisting of monolaurin which exhibits antibacterial, antifungal, antiviral, and antiprotozoal effects. However, coconut oil is relatively immiscible with water, the main composition of human body. This study was thus focused on the development of nanoemulsions containing coconut oil employing the combination of several surfactants and variation of mixing speed for the purpose of overcoming the immiscible problem. Formulations of nanoemulsions were prepared within this study. The HLB values were then measured and used to determine the compatibility between coconut oil and surfactants. Moreover, the speed of homogenizer which might have a significant impact on the physical properties of nanoemulsions, was taken into account. Meanwhile, particle size, zeta potential, pH, long-term stability, and antibacterial activity were also examined. According to the results, the nanoemulsions prepared from 10% (w/w) of coconut oil and 10% (w/w) of surfactants comprising of Tween® 80 and Span® 80 in the ratio of 2 to 3 at the homogenization speed of 15000 rpm seemed to be suitable for topical administration with the characteristics as follows: the droplet size of 254.7±0.016 nm, the zeta potential of-4.41±1.46 mV, and the pH values of 6.13± 0.01. In addition, coconut oil formulated in the form of nanoemulsions demonstrated the efficient antimicrobial activities against Staphylococcus aureus, a gram-positive bacteria. In conclusion, this study represents the effect of mixing speed on the properties of nanoemulsions containing coconut oil which could be further developed as a substitute for topical antibiotics.

Thermosensitive polysaccharide particles for pulmonary drug delivery

In the present study, we have prepared drug carriers for pulmonary administration: temperature-responsive polysaccharide particles prepared through an emulsion formation and a subsequent sol-gel transition of polysaccharides. The particles are obtained by the cooling of w/o (water-in-oil) emulsions prepared from an aqueous polysaccharide solution and a surfactant-dissolving organic solvent. We found that highly stable s/o (solid-in-oil) suspensions were formed regardless of HLB value, structure, and composition of the surfactants when high-molecular-weight surfactants were used. There are two possible important factors affecting the formation of spherical κ-carrageenan particles: (1) the formation of physically crosslinked domains inside the particle by means of the increase of concentrations of polysaccharides and cations and (2) the formation of a stable solid-liquid interfaces by using high-molecular-weight surfactants. We obtained stable polysaccharide particles with dimpled surfaces. As a result of the in vitro aerosol dispersion performance of the κ-carrageenan particles with the cascade impactor, we identified the characteristic delivery behavior of κ-carrageenan particles: the κ-carrageenan particles delivered more to the alveoli than to the pharynx and bronchi, despite their high density. The present study shows that the “dimpled” κ-carrageenan particles can likely stay in the alveoli so that high therapeutic effects will likely occur in pulmonary administration.

Protonation, geometry, charge, and partitioning properties of several prepared heterocyclic derivatives

Several heterocyclic derivatives were evaluated experimentally to determine their physical properties and antimicrobial activity. Then these compounds were tested with Marvinsketch program to determine their protonation, geometry, charge, and partitioning. Partitioning characters (log P and log D at pI) were calculated by Consensus and Chemaxon methods while HLB was with Chemaxon and Davies methods. For example, the derivatives of EDTA based structure showed that isoelectric point (pI) did not affected by the presence of negative charge compared with its zero charge. As is expected, negative charge, presence of sulfur atoms, and type of heterocyclic moiety had a good influence on HLB values. The obtained results confirmed high harmonization between the experimental and computerized calculations especially when several of them where tested against Staphylococcus aureus, Bacillus subtilus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans.

Probing the effect of various lipids and polymer blends on clopidogrel encapsulated floating microcarriers.

Clopidogrel (CLOP) is an antiplatelet drug with poor solubility in intestinal fluid, which limits its bioavailability after oral administration. Current study focuses on developing site-specific floating microcarriers of CLOP using solvent diffusion evaporation method (SDEM) for retaining the drug in the stomach, thus improving the solubility of drug for better absorption. SDEM was employed to formulate floating microcarriers using lipidic excipients, namely Gelucires (GL) to impart floating properties, in combination with ethyl cellulose as release retarding polymer. Prepared particles were 169 ± 6μm to 375 ± 13μm in size, whilst encapsulation efficiency was ranged from 39.6 ± 0.60% to 96.50 ± 3.50%. Electron micrographs depicted discrete spherical microcarriers with porous structure, which amplified with increasing HLB value of GL and concentration of Eudragit E100. FTIR study confirmed absence of major drug polymer interactions while DSC and XRD studies revealed the presence of non-crystalline nature of drug in all formulations. Drug release at pH1.2 enhanced more than 2-folds with increasing HLB value with 32% cumulative drug release for GL 43/01 and 69% for GL 50/13. More interestingly, adding various proportions of Eudragit E100 to GL 43/01 based formulations resulted in increased drug release as high as 71%. In all formulations, the drug release followed diffusion dependent process. It is envisaged that this formulation strategy for CLOP is promising and could possibly be tested in future for its in vivo performance. Graphical abstract Lipid based floating microcarriers of clopidogrel.

Size-Tailored Design of Highly Monodisperse Lipid Nanocapsules for Drug Delivery.

The empirical development of nanocarriers has unfortunately led to high attrition rates in clinical trials. This underpins the importance of the rational design of nanomedicines to achieve efficient disease-driven therapies. Since particle size certainly influences in vivo behaviour, rational disease-driven colloid design can only be achieved by determining the parameters that accurately control their size distribution. To this end, we have thoroughly revisited the parameters that drive the phase-inversion temperature nanoemulsification method to obtain kinetically stable and monodisperse lipid nanocapsules. Notably, we have evidenced that the major parameter driving nanocapsule formation is the oily phase/surfactant ratio and consequently, we have established a linear univariate mathematical model that predicts the particle size distribution for various oily phase-surfactant combinations (R² > 0 99). Furthermore, we have observed that the difference between the HLB values of the surfactants and the triglycerides utilized as oily phase correlates with the steepness of the slope of the linear mathematical model. This model will bring the implementation of size-tailored lipid drug carriers determined by pathophysiological features a step closer. Importantly, this model pioneeringly fits all data available in the literature on size distribution of colloids prepared by low-energy methods and that were originally evaluated following other parameters. Moreover, the nanocapsules have been obtained following a single-step process, with the ensuing potential for a future scale-up in an energetically-efficient manner. These findings will eventually enable nanomedicines to be obtained "on-demand" to meet disease-driven criteria in terms of particle size and will also increase their chances of success.

Effects of emulsifying systems on preparation of lavender flavor liquid nanocapsules

Herein, the influences of commercial emulsifying systems properties on the performance of the lavender flavor liquid nanocapsules are studied by using chitosan as the wall material and the lavender flavor as the core material, and seven commercial emulsifiers: Tween-20, Tween-40, Tween-60, Tween-80, Tween-85, Span-80 and CO-40, are chosen to constitute the emulsifying systems. Firstly, lavender flavor nanocapsules are prepared with different emulsifiers and the corresponding pseudo-ternary phase diagrams are drawn to illustrate the effects of structures of emulsifier on performances of liquid nanocapsules. Meanwhile, nanocapsules are also prepared with emulsifying systems of different HLB values, the results show that, nanocapsules can be formed easily when the HLB value of emulsifying systems matching up with the RHLB value of lavender flavor. Finally the effect of structures of co-emulsifier and the values of K m on performance of nanocapsules are also investgated. The results show that, by using CO-40 and Span-80 as emulsifiers, 1,2-propylene glycol as a co-emulsifier, when K m equals to 3 and S/O value is greater than 7:3, the obtained lavender flavor liquid nanocapsules are transparency, which have a diameter of about 10 nm with low dispersion.

PENGEMBANGAN SEDIAAN EMULGEL MENGANDUNG MINYAK BIJI ANGGUR (Vitis vinifera L.) DAN UJI AKTVITAS ANTILUKA TERHADAP TIKUS WISTAR JANTAN (Rattus norvegicus)

Grape seed oil has wound healing activity since contains compounds such as flavonoids, polyphenols, saponins and linoleic acid. The purpose of this study is formulate emulgel containing grape seed oil with good physical characteristic and observed the wound healing activities of the oil and formulated emulgel. The research was begin with grape seed oil characterization and required HLB determination. The emulgel was made using combination Tween 80 and Span 80 as emulgator and carbomer as gelling agent with variation of oil concentration (10%, 20% and 30%). The formulation then subjected to physical evaluations including organoleptic, pH, spreadability, viscosity and rheology, sterility, and stability tests. Wound healing activity test of selected formula was done on seven groups of male Wistar rats. The emulgel containing grape seed oil with HLB value 8, has good physical, sterility, and stability characteristics. In vivo activity test showed that emulgel containing 20% and 30% grape seed oil have wound healing activity that statistically different compared with control (P 0.05).

ROLE OF HYDROPHILIC SURFACTANTS IN THE EMULSIFICATION MECHANISTICS OF TYPE III SELF-MICRO-EMULSIFYING DRUG DELIVERY SYSTEMS (SMEDDS)

Objective: Evaluation of the self-emulsifying behaviour of type III lipid systems comprising mixed medium chain glycerides (Miglyol 812-Imwitor 988) and wide range of hydrophilic surfactants in an attempt to identify self-emulsifying microemulsion formulations, prevaricate the crystallization tendency of Cremophor RH40 in the pre-microemulsion concentrate, to shed some light on the mechanistic behavior of these systems after aqueous dispersion.
 Methods: Non-ionic surfactants with HLB in the range 14 to 16.5 are investigated amongst these are; Cremophor RH40, Cremophor EL, Crillet 4 (polysorbate 80), Crillet 1 (polysorbate 20) and Tagat O2. Optimum oil blends of Miglyol 812-Imwitor 988 and various non-ionic surfactant systems were verified using self-emulsification performance studies, oil droplet diameter measurements and dynamic equilibrium phase studies.
 Results: Oil blends of Miglyol 812 as an oil and Imwitor 988 as a cosurfactant were optimized for microemulsion systems at ratios of 1:1 in the case of Cremophor RH40 or EL, and at 2:3 in the case of Crillet 4 or Tagat O2. In order to obtain small droplet size and fast dispersion rate for type III lipid systems, hydrophilic surfactants with HLB values between 13 and 15 were found to be the optimum.
 Conclusion: Spontaneous micro-emulsification in type III lipid system was attributed to the “diffusion and stranding” theory. Yet, the formation of liquid crystalline phases as intermediate phases during dilution of the oil formulation with water appears to be quintessential for the mechanistics of emulsification regardless type of lipid class system.

The hydrophilic-lipophilic balance of carboxylate and carbonate modified nonionic surfactants

The shift of the phase inversion temperature (PIT) of n-octane/water nonionic surfactant (C13EO5) emulsions was studied as a function of increasing amounts of an additional second surfactant in order to rank them according to their hydrophilic-lipophilic-balance. Two different groups of modified nonionic surfactants were investigated with the objective to quantify the contribution of the modified groups to the HLB value of the surfactants. One modification was obtained by copolymerization of ethylene oxide and CO2 for the synthesis of the hydrophilic head group. The second was the capping of the head group with a −CH2−COOH group. Well-defined polyethoxylated alkyl surfactants (CiEj) show a linear variation of the PIT with their mole fraction X2 and can be used as standards to calibrate a scale in terms of dPIT/dX2. With this method, it can be shown that the −CH2−COOH decreases the HLB value in comparison to an unmodified version of the same surfactant when measured at acidic pH values. The modification with CO2 increases the HLB value almost in the same way as the addition of the same number of EO units. This observation reveals the potential of a replacement of EO by CO2 to a certain extent, saving fossil resources, reducing the carbon footprint of the products and introduces a new tuning parameter for chemical and physical properties of the new group of surfactants.

Preparation, characterization and in vivo evaluation of novel hyaluronan containing niosomes tailored by Box-Behnken design to co-encapsulate curcumin and quercetin

Designing novel drug delivery systems to improve drug efficiencies have gained great interests in recent years. In this study, a new vesicular system has been prepared using thin film hydration method with slight modifications, hydrophobic drugs have been used in both lipophilic and hydrophilic phases and dry film was hydrated by hyaluronan polymeric solution, to overcome curcumin and quercetin formulation drawbacks. Briefly, different formulations were prepared according to Box-Behnken design to assess the effect of HLB value, cholesterol and hyaluronan contents on the properties of niosomes. Then, the best formulation was selected for further studies and compared with conventional niosomes. The results showed that both niosomes had spherical shapes according to Transmission Electron and Atomic Force Microscopic images. Results also showed that hyaluronan containing niosomes had smaller size and higher values of zeta potential and entrapment than conventional niosomes. The average size of hyaluronan containing niosomes was 260.37 ± 6.58 nm, the zeta potential was −34.97 ± 1.50 mv and the entrapment for curcumin and quercetin were 98.85 ± 0.55% and 93.13 ± 1.22%, respectively. The release kinetic of quercetin was best fitted to Peppas model for both conventional niosome and hyaluronan containing niosomes; while, the release kinetic of curcumin was best fitted with non-conventional order 2 and three second roots of mass for hyaluronan containing niosomes and conventional niosomes, respectively. Hyaluronan containing niosomes showed higher antioxidant and anti-inflammatory effects in comparison with conventional niosomes.

Adjusting and Resetting of the Pre-determined Storage Temperature for O/W Emulsions

Adjusting and resetting the predetermined storage temperature of O/W miconazole cream from 20-24° to be 30° to coincide with the storage temperature of the Egyptian climatic ICH/WHO zone IVA was the objective of this work. Eight sets of miconazole cream were prepared by using different proportions of the oil phase ingredients while their ratios were fixed at 30 %. The calculated HLB values of the oil phases were 9.067, 9.134, 9.2, 9.267, 9.36, 9.46, 9.566 and 9.6. These eight sets have same optimum surfactants blend proportions equal to 0.5:0.5 and same effective surfactant blend concentration equal to 7 %. Sets which have storage temperature equal to 30±2° were assessed according to the acceptance criteria of the accelerating stability testing protocol for O/W emulsions stabilized by nonionic surfactants (aqueous surfactant two-phase systems) as previously reported. Only two sets, numbered 2 and 4 with storage temperature of 30.5 and 32°, respectively met the acceptance criteria of aqueous surfactant two-phase system. The applicability and validity of the method was confirmed by measuring zeta potential and particle size distribution of original miconazole cream set, set numbers 2 and 4. Zeta potential and particle size distribution of the three sets were measured on a Zetasizer with zeta potential results equal to -20, -30.7, -41.7 mV and particle size distribution results equal to 560.8, 387.6, 386.5 nm, respectively. Particle size distribution was also measured using a transmission electron microscope with results equal to 84.875, 49.168 and 46.05 nm, respectively. These results indicated that zeta potential defined the emulsion stability accurately and precisely whereas particle size distribution measurement gave unreliable and indefinite results. Zeta potential results revealed that the increase in the storage temperature of emulsion to 30° is accompanied by an increase in its stability. Increasing temperature beyond 30 is possible and would result in subsequent increase in stability due to the presence of liquid crystalline phase below 35°, which contributes significantly to emulsion stability while the destructive effect of the temperature starts at 35°. Unreliable and indefinite results of particle size measurement proved that the droplet diameter and droplet size measurement reported in many reports is more convenient. This work described a theory to determine the storage temperature of materials, pharmaceuticals, foods and cosmetics obeying non-Newtonian plastic flow.

Emulsion Polymerization of P (MMA-AA-EA) and Its Demulsifying Performance in Water/Oil Emulsion

Stable water-in-oil emulsions are produced in oil exploitation and cause many environmental and operational issues. In this paper, a co-polymer demulsifier is reported in detail; an emulsion polymerization method is used to prepare nano-P (MMA-AA-EA) with MMA, AA and EA as the monomers, DVB as the cross-linker and APS as the initiator. The resulting products are characterized by FT-IR. Furthermore, the surface tension and particles size analysis is investigated. The results show that the surface tension reduction is 10.66 mN/m at 20°C when the concentration of co-polymer is 1000 ppm and the average size is 76.99 nm. Moreover, the HLB of polymer is discussed specifically by changing the amount of AA. With the increase of AA, the HLB value of the polymer is increased accordingly. Besides, the demulsification performance of the co-polymer is also evaluated at different synthesis and demulsification conditions. It is showed that the maximum demulsification efficiency is 96% at 70°C for 60 min. The optimum concentration of demulsifier is 400 ppm when the amounts of AA and DVB are 1.4 g and 0.1 g, respectively. At last, the process of demulsification is showed under a microscope; the coalescence process of water droplets is indicated under the action of the demulsifier.

Polymeric surfactants with tricyclic rigidity from natural rosin: Synthesis and dispersion of single-walled carbon nanotubes in aqueous solution

Polymeric surfactants from natural rosin containing a unique tricyclic rigid structure were prepared and their structures were characterized by IR, 1H NMR and GPC. Their surface activities including hydrophile—lipophile balance values (HLB), emulsification properties, foaming properties, critical micelle concentration (CMC) and the minimum surface tension (γCMC) were evaluated. With the increase in ratio of hydrophobic to hydrophilic in polymeric surfactant, the CMC values of the surfactants decreased, and the emulsification and foaming properties of these surfactants increased, and the HLB values of them decreased. This type of polymeric surfactants was used to disperse single-walled carbon nanotubes (SWCNTs) in water, and their dispersal capacities were comparatively determined by UV-visible absorption spectroscopy. Thermogravimetric analysis (TGA) was used to quantify the amount of surfactant attached onto the nanotubes. More intuitive image of their dispersion states were obtained by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The results showed that this type of polymeric surfactants had good dispersion capacity and dispersion stability to SWCNTs in water through strong hydrophobic attraction and weak van der Waals interactions.

Topical gel of Metformin solid lipid nanoparticles: A hopeful promise as a dermal delivery system.

The aim of the present study was to enhance the skin delivery of metformin by making solid lipid nanoparticles containing metformin using the ultra-sonication method. To achieve the optimum skin delivery for metformin, the effects of the ratio of two surfactants (Tween:Span) on nanoparticles properties and their performance were investigated. Photon correlation spectroscopy, scanning electron microscopy (SEM), Powder X-ray Diffractometer (PXRD), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were used to characterize the solid state of metformin in solid lipid nanoparticles. Generally, the particle size of nanoparticles decreased by the addition of co-emulsifier (Span®60). Results showed that all formulations made by binary mixtures of surfactants had low particle size, low Polydispersity index and high zeta potential. It was interesting to note that the smallest nanoparticles (203.8 ± 15.356) was obtained when the HLB of the binary surfactants (HLB of 11.67) was closer to the HLB of beeswax (HLB of 12) used in the preparation of SLN. It was also found that by decreasing the HLB of the system from 14.9 to 10.06 the zeta potential of SLNs increased from -0.651 ± 0.315 to -6.18 ± 0.438 mV. But, a further reduction in the HLB from 10.06 to 8.45 caused a reduction in the zeta potential from -6.18 to -3.596 ± 0.255. Results showed that the highest entrapment efficiency of 45.98 ± 9.20% was obtained for formulation with larger particle size and with the highest HLB value (HLB 14.9). DSC study showed that metformin in SLN is in an amorphous form. FT-IR spectra of Met-SLN showed that the prominent functional groups existed in the formulations which could be an indication of good entrapment of metformin in a lipid matrix. FT-IR results also ruled out any chemical interaction between the drug and the excipients. The amounts of metformin detected in the skin layers and the receptor chamber at all sampling times were higher for nanogel compared to metformin gel. This is an indication of a better performance of Metformin nanogel ex-vivo and could be developed further for clinical studies.

Alkyl rhamnosides, a series of amphiphilic materials exerting broad-spectrum anti-biofilm activity against pathogenic bacteria via multiple mechanisms

As novel amphiphilic materials, six uncharged alkyl rhamnosides incorporating various alkyl chain and one rhamnose amine quaternary ammonium salt were successfully synthesized in this study. Their amphiphilic properties (HLB and CMC), antimicrobial and anti-biofilm activity against S. aureus and P. aeruginosa were investigated. Differentially regulated proteins and pathways were identified by comparative proteomics research to first give a sight on how alkyl rhamnosides performed the anti-biofilm activity at protein and pathway levels. Among the uncharged alkyl rhamnosides, dodecyl rhamnoside and octyl rhamnoside showed the best antimicrobial and anti-biofilm ability against S. aureus and against P. aeruginosa, respectively. Interestingly, the relationships between amphiphilic properties or MIC with anti-biofilm activity were first established. Uncharged alkyl rhamnoside with an optimized HLB value of 5.0 had both the strongest antibacterial and anti-biofilm activity against S. aureus, and MIC was the maximum biofilm inhibitory concentration for all alkyl rhamnosides. Alkyl rhamnosides have a significant overall regulatory effect on the proteomics and pathways of bacterial biofilms, including energy production, substrates transportation, signal transduction, key molecules balance, and so on. These amphiphilic materials have a great potential to be used as additives in pharmaceutic, cosmetic, food industry, hospital and in other non-medical fields.

Partition Coefficient and Glutathione Penetration of Topical Antiaging:Preformulation Study

Glutathione (GSH) is a broad antioxidant of the thiol-tripeptide group, highly hydrophilic, which has limitation for topical preparations. A lipophilic surfactant is an alternative method to enhance the glutathione partition. The purpose of this study was to determine the apparent partition coefficient (APC log) of glutathione; glutathione with additional surfactant at different HLB value of HLB 4.3; 5.5; 7; 11 and selected HLB was studied for penetration. The study was conducted by dissolving glutathione in water plus various HLB surfactants. Determination method of partition coefficient was done by shake flash method. The penetration test was conducted using the parameter of decreasing Matrix Metalloproteinase-1 expression on the balb-c male skin. The results can be used as a reference for topical glutathione formulations as these results are preformulation study.

Sporicidal activities and mechanism of surfactant components against Clostridium sporogenes spores.

The sporicidal activities of seven kinds of antimicrobial agent were investigated in order to screen for novel inactivation agents to apply to Clostridium sporogenes spores. Antimicrobial agents based on surfactant components, as poly-l-lysine, thiamine dilaurylsulfate, and torilin, were more effective than other agents. The degree of spore reduction with 1-2% surfactant components was 1.5-2.5logCFU/mL. The HLB value (hydrophile-lipophile balance) related to denature protein of spores coat on surfactants with sporicidal activity was ranged from 6 to 16. Average HLB value and spore killing effect was inversely correlated. The proteins on spore structures seemed to be disorganized due to binding between polar groups of coats and hydrophilic and hydrophobic groups of surfactant components, resulting in killing of spores. The components that were effective to inactivate C. sporogenes spores had a chemical structure containing CH3, OH, COOH, sulfate groups, and a double bond. Furthermore, hydrophobic surfactants were more effective than hydrophilic surfactants in inactivating spores. This was likely due to the type of hydrophobic surfactant and to the involvement of hydrophobic interactions on coat of spores.