Ideal Critical Micelle Concentration Research Articles

Micelle formation and physico-chemical variables for the sodium dodecyl sulfate/cetylpyridinium chloride and their mixture in aqueous propranolol hydrochloride drug solvent: Conductivity and theoretical analysis

Herein, study of both single and mixed micelle development of an anionic surfactant sodium dodecyl sulfate (SDS) and a cationic surfactant cetylpyridinium chloride (CPC) in propranolol hydrochloride (PPH) drug medium has been performed using a conductometric technique at different temperatures and compositions. The critical micelle concentration (CMC) along with degree of ionization (g) were assessed from the specific conductivity (κ) versus [surfactant] plots. Within the concentration of surfactant studied, a single CMC was achieved in the situations of pure and mixed surfactant micellization. The CMC and g values have been noticed reliant on the employed drug concentrations, variations of mole fractions of the mixture of surfactants and experimental temperature. For the micellization of single SDS/ CPC surfactants in aq. PPH drug medium, PPH drug causes delayed micelle development which has been detected as the upsurge of CMC values of SDS/CPC in PPH drug media. For the association of SDS/ CPC surfactants in aq. PPH drug medium, the CMC values experienced a lessening with the growth of study temperature. At a fixed temperature, the experimental CMC values, of the SDS + CPC mixture, endure a decline through the upsurge of mole fractions of CPC (α1), attain a minimum value and the CMC values tend to enhance at and above α1= 16.2 × 10-5. The ideal critical micelle concentrations (CMCid) are detected always as higher values than experimental CMC up to the α1= 10.8 × 10-5. The -β values and |β| > |ln(CMC1/ CMC2)| for the present study reveal that the interaction among the amphiphiles under analysis is synergistic. The negative free energy (-ΔGmO) of micellization were obtained throughout the study. The enthalpy (ΔHmO) and entropy (ΔSmO) of micellization reveal the presence of hydrophobic interaction as the principal type of interaction among the studied constituents. The negative excess free energy (ΔGex) values inferred that stable mixed micelles are formed for the mixture of SDS + CPC in aq. PPH drug medium. The micellar mole fractions (both experimental and ideal values), activity coefficients of components in mixed micelles as well as enthalpy–entropy compensation parameters were also measured and illustrated. It is possible that the knowledge gained from the current analysis may be used to enhance pharmaceutical formulations, drug delivery carriers, along with drug act proficiency.

Unravelling the Interactions Prevailing in Mixed Micellar System of Surface-Active Ionic Liquid and Cationic Surfactant

The investigation of mixed micellar behavior of surface-active ionic liquid (SAIL) i.e. 1-butyl-3-methylimidazolium hexadecyl sulfate [C4mim][HS] with cationic surfactant cetyltrimethylammonium bromide (CTAB) has been done to explore the type of interactions prevailing in SAIL/Surfactant mixed system. Thus, the conductometric measurements are performed at (298.15, 308.15 and 318.15) K for various mole fractions of [C4mim][HS]. Different theoretical models like Clint, Rubingh, Motomura and Rodenas have been applied to understand mixed micellar behavior of SAIL/Surfactant mixed system. The value of critical micelle concentrations (cmc), micellar mole fraction based upon various models, ideal critical micelle concentrations (cmc*), interaction parameter (β) and thermodynamic parameters have been evaluated for the mixed systems. The variations of various parameters with respect to temperature and mole fractions give insight to sort of interactions present in studied system.

Transition from antagonistic to synergistic interaction in mixed micellar system by increase in alkyl chain length of alkyl trimethylammonium bromide

Herein, the electrical conductivity technique used to measure the critical micelle concentration (cmc) for pure cationic surfactants (Dodecyl/cetyltrimethylammonium bromides) and phenothiazine drug (Promethazine hydrochloride), as well as their different mole fractions in 10−3 ​mol/kg 1-methyl-3-octylimidazolium chloride (C8mim.Cl) at different temperatures. By using the cmc values the regular solution theory used to evaluate the micellar mole fraction for DTAB/CTAB-PMT mixed systems. The clint's model used to calculate the ideal critical micelle concentration (cmc∗) that helps to evaluate the ideal micellar mole fraction for studied mixed systems, both explain the deviation from ideality. In addition, interaction parameter βm helps to confirm the nature of interaction (either antagonistic or synergistic) for the studied systems. The calculated parameters confirm a transition in the binding nature from antagonistic to synergistic with the increase in alkyl chain length of cationic surfactant i.e., component of the binary mixed system. The ease of micellization for the studied systems discussed by the standard Gibb's energy of micellization (ΔGm0), as well as the standard enthalpy and standard entropy of micellization were (ΔHm0) and (ΔSm0), respectively to discuss the stability of the studied systems.

Study on the treatment of oily sludge in oil fields with lipopeptide/sophorolipid complex bio-surfactant

A systematic study had been carried out to get insight into the micellar behavior of anionic lipopeptide (LT) and nonionic sophorolipid (SL) in their different mass ratio mixed state using the technique of tensiometry. The models proposed by Clint, Rubingh and Gibbs et al. had been employed to interpret the formation of mixed micelles and found out synergism. The obtained experimental critical micelle concentrations (CMC) were lower than the ideal CMCs, indicating negative deviation from ideal behavior for all multi-component mixed micelles formation. A suited binary bio-surfactant mixing system was selected as the washing agents to treat the oily sludge produced from Huabei oilfield by the thermal bio-surfactant washing method. The results showed that in case of the mass ratios of 8:2 the CMC was dramatically decreased and synergism was the strongest in LT and SL bi mixed surfactant systems. The studied binary mixed bio-surfactant system showed higher washing efficiency for oily sludge than single surfactant system. In addition, the washing power of binary mixed bio-surfactants towards oily sludge was the best at below washing conditions: (a) the concentration of the mixed system (100 mg/L), (b) temperature (55 ℃), (c) ratio of sludge/liquid (1:3), (d) washing time (3 h), and (e) stirring speed (300 rpm). Certainly, the washing abilities of the selected surfactants not only depend on their mixing ratio and washing conditions but also associate with microstructure and mineral components of oily sludge.

Aggregation Behavior of Mixed Micellar System of Dodecyl Sulfate‐Based Surface‐Active Ionic Liquids and Anionic Surfactant in Aqueous Media

AbstractMixed micellization behavior of dodecyl sulfate‐based ionic liquids, i.e., 1‐propyl‐3‐methylimidazolium dodecyl sulfate [C3mim][DS] and 1‐hexyl‐3‐methylimidazolium dodecyl sulfate [C6mim][DS] with sodium dodecyl sulfate (SDS), is investigated at (298.15, 308.15, and 318.15) K in aqueous medium. For this, the conductometric measurements are carried out to evaluate the critical micelle concentrations (cmc), ideal critical micelle concentration (cmc*), degree of counterion dissociation (g), thermodynamic parameters, micellar mole fraction of ionic liquids, and interaction parameter (β) of the mixed system based on the different proposed models given in the literature. Further surface tension measurements have been carried out to confirm the value of cmc obtained via a conductivity study for all the studied systems at 298.15 K. Other surface parameters, such as surface tension at cmc (γcmc), surface pressure (ᴨcmc), surface excess (Γmax), and minimum area per molecule (Amin), have also been evaluated for both the systems.

Synergistic Solubilization of Phenanthrene by Mixed Micelles Composed of Biosurfactants and a Conventional Non-Ionic Surfactant

This study investigated the solubilization capabilities of rhamnolipids biosurfactant and synthetic surfactant mixtures for the application of a mixed surfactant in surfactant-enhanced remediation. The mass ratios between Triton X-100 and rhamnolipids were set at 1:0, 9:1, 3:1, 1:1, 1:3, and 0:1. The ideal critical micelle concentration values of the Triton X-100/rhamnolipids mixture system were higher than that of the theoretical predicted value suggesting the existence of interactions between the two surfactants. Solubilization capabilities were quantified in term of weight solubilization ratio and micellar-water partition coefficient. The highest value of the weight solubilization ratio was detected in the treatment where only Triton X-100 was used. This ratio decreased with the increase in the mass of rhamnolipids in the mixed surfactant systems. The parameters of the interaction between surfactants and the micellar mole fraction in the mixed system have been determined. The factors that influence phenanthrene solubilization, such as pH, ionic strength, and acetic acid concentration have been discussed in the paper. The aqueous solubility of phenanthrene increased linearly with the total surfactant concentration in all treatments. The mixed rhamnolipids and synthetic surfactants showed synergistic behavior and enhanced the solubilization capabilities of the mixture, which would extend the rhamnolipids application.

Properties of Binary Mixture of Cetyl Diphenyl Ether Disulfonate and Linear Alkylbenzene Sulfonate

Abstract The surface properties of the binary mixture of cetyl diphenyl ether disulfonate (C16-MADS) and linear alkylbenzene sulfonate (LAS) have been investigated by salinity and hardness tolerance, equilibrium surface tension, wettability, foam and emulsification measurements. The results show that with increasing mass ratio of LAS in the C16-MADS/LAS mixed system, the ability to reduce the surface tension of the solution is improved. The wetting performance is also improved. The critical micelle concentration (CMC) values are increased first, then decreased, and are higher than the ideal CMC values, which indicates that there is an antagonistic effect that is not conducive to the formation of mixed micelles between C16-MADS and LAS. In addition, the C16-MADS/LAS system improves the hard water resistance of LAS and reduces the foam properties of LAS.

Influence of Electrolyte and Temperature on the Aggregation Behaviour of Mixed System Consisting Drug and Anionic Surfactant

At present work, the interaction of amphiphilic drug promazine hydrochloride (PMZ) with anionic surfactant sodium dodecyl sulfate (SDS) and imipramine hydrochloride (IMH) with anionic surfactant dioctyl sulfosuccinate sodium salt (AOT) in the absence and presence of 50 mmol.kg−1 inorganic salt is investigated in aqueous medium at different temperatures. For this, conductometric measurements were carried out to evaluate the critical micelle concentrations (CMC) of drug and surfactant. Ideal critical micelle concentration (CMC id) and interaction parameter (β) has also been evaluated. The deviations obtained in values of CMC and CMC id indicate the interaction between drug and surfactant. Other micellar mole fraction parameters such as X1 Rub (Rubingh), X1 Mot (Motomura), X1 Rd (Rodenas) and X1 ideal (ideal mole fraction) are also evaluated based on different proposed models. Other thermodynamic parameters of micellization such as, standard free energy of micellization , standard enthalpy of micellization , and standard entropy of micellization are also evaluated based upon the equations already present in literature to understand the interactions prevailing in the studied systems.

Effects of alkyl chain length on synergetic interaction and micelle formation between a homologous series of n-alkyltrimethylammonium bromides and amphiphilic drug propranolol hydrochloride

The aggregation behavior of a homologous series of n-alkyltrimethylammonium bromides (CnH2n+1TAB; n = 12, 14, and 16) in the presence of amphiphilic drug propranolol hydrochloride (PPL) in aqueous solutions were studied using conductometric technique. The critical micelle concentrations (CMCs) were determined for pure PPL and surfactant as well as mixed micelles [surfactant(1)/PPL(2)] using the Carpena method. Various physicochemical parameters such as ideal CMC (CMCid), degree of counter-ion binding (α), micellar mole fractions of surfactant (X1m and X1id), interaction parameter (βm), the activity coefficients of components (f1m and f2m), standard Gibbs free energy of micellization (ΔGmic0) and the excess free energy of micellization (GmicE) values have been calculated and compared in detail using Clint's and Rubingh's theories. The activity coefficients of surfactant and PPL are less than 1 (f1m < 1 and f2m < 1) and the values of βm are negative in all mixtures, which indicates the synergistic interaction between surfactant and PPL. Also, the results show that the synergistic effects of mixed micelles strongly depend on the chain length of cationic surfactant, and the values of interaction parameter increase with increasing the alkyl chain length of surfactant. Of the several interactive interactions, it seems hydrophobic interaction is the most dominant interaction between the molecules of the mixed systems among all observed interactive interactions in this study.

Ecotoxicity and micellization behavior of anionic surfactant sodium dodecylbenzene sulfonate (SDBS) and its mixtures with nonionic surfactant fatty alcohol-polyoxyethylene ether (AEO)

Surfactant mixtures have extensive industrial applications due to their ideal properties and low ecotoxicity. However, the ecotoxicity of surfactant mixtures with different proportions and their correlation with surface properties have remained poorly investigated. In this study, the ecotoxicity and surface activity of the composites of anionic surfactant sodium dodecylbenzene sulfonate (SDBS) and nonionic surfactant fatty alcohol-polyoxyethylene ether (AEO) in various mass ratios were assessed, and the correlation between ideal application properties and safe ecological perspective of the composites was explored. The ecotoxicity of individual SDBS, AEO, and SDBS/AEO mixtures was determined using the bioluminescence inhibition assay with Photobacterium phosphoreum, and the critical micelle concentrations (CMC) were measured by surface tension method and steady-state fluorescence spectroscopy. Sodium dodecylbenzene sulfonate (SDBS) showed a considerably higher toxicity than individual AEO and SDBS/AEO mixtures. Scanning electron microscope images illustrated the rupture of bacteria membrane induced by SDBS, and the addition of AEO alleviated the damage. According to the dose–response relationship on luminous bacteria, SDBS/AEO mixtures were divided into three groups (group I with a high proportion of SDBS, SDBS:AEO = 4:1 and 3:2; group II, SDBS:AEO = 1:1; group III with a high proportion of AEO, SDBS:AEO = 2:3 and 1:4). The sequence of toxicity of the SDBS/AEO mixtures was group II > group III > group I, demonstrating that the toxicity of the composites was related to the mixture proportion instead of the amount of AEO added. The CMC order of SDBS/AEO mixtures was group II > group I > group III, and it was proportion dependent. Furthermore, ΔCM was defined as the difference of the experimental (CM) and ideal CMC (CMideal) of the mixed system, indicating the interaction between the two kinds of surfactants. The order of the ΔCM was group II > group III > group I, which was consistent with the sequence of the toxicity. Therefore, ΔCM can be a potential indicator for the hazardous assessment of surfactant mixtures involving high ionic strength.

Aggregation behavior of cetyltrimethylammonium bromide and tetradecyltrimethylammonium bromide in aqueous/urea solution at different temperatures: Experimental and theoretical investigation

The solution properties of mixed amphiphiles system play a promising role in the surface chemical applications. Aggregation behavior of two cationic surfactants as tetradecyltrimethylammonium bromide (TTAB) and cetyltrimethylammonium bromide (CTAB) has been taken into account in detail using conductivity measurements and theoretical calculations in water medium and urea (NH2-CO-NH2) solution over temperature range of 298.15 K to 318.15 K. The critical micelle concentration (cmc) for pure CTAB, TTAB and CTAB + TTAB mixtures as well as the ideal critical micelle concentration (cmcid) for CTAB + TTAB mixed system were evaluated in attendance/absence of urea (300 mmolkg−1 and 800 mmolkg−1). The cmc values of CTAB + TTAB mixtures are observed to be less than cmcid values imply that attractive interaction occurs between these two surfactants. The activity coefficients (f1 and f2) and the micellar mole fraction of CTAB (X1) were assessed by applying different models such as Rubingh, Motomura and Rodenas; the results suggest the existence of more contribution of CTAB in mixed micelles and their values increases by enhance of the mole fractions of CTAB. The β values were estimated to get insights of the interactions between the surfactants (TTAB & CTAB) by proposed Rubingh model. The ∆H0m and ∆S0m values reveal that the possible binding forces between TTAB and CTAB are hydrophobic as well as electrostatic interactions. The excess free energy (∆Gex), the compensation temperature (Tc) as well as the intrinsic enthalpy gain (∆H0,⁎m) were determined and discussed in detail.

Interaction of tetradecyltrimethylammonium bromide with sodium dodecyl sulfate in aqueous/urea medium at several temperatures and compositions

The simple and reliable conductivity measurement method has been inaugurated to disclose the mixed micellization behavior of two ionic surfactants (tetradecyltrimethylammonium bromide (TTAB) plus sodium dodecyl sulfate (SDS)) in H2O/NH2-CO-NH2 (urea) medium at several temperatures and compositions. The experimentally evaluated critical micelle concentration (cmc) are different those from their corresponding ideal critical micelle concentration (cmcid) which signifies the mutual interaction (attractive/repulsive) amongst the current constituents. The higher cmc values of distinct surfactant and mixed system in occurrence of NH2-CO-NH2 compare to water medium which also further increase through raising the amount of urea. In urea medium, the extent of degree of dissociation (g) is lower at superior composition of TTAB which implying better packing of surfactants aggregates. The magnificence of micellar mole fractions of TTAB depending of various proposed models & their ideal X1id values were executed and the executed outcomes suggesting the strong contributions of TTAB in the SDS-TTAB mixed micellization. Activity coefficients of TTAB & SDS, f1 &f2 < 1 indicate the attractive interaction amid SDS and TTAB. The negative values of ΔG0m & ΔH0m suggest the spontaneity of micellization & exothermic micellization process respectively. The executed ΔS0m values were positive in all cases studied herein.

Conductometric and molecular dynamics studies of the aggregation behavior of sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) in aqueous and electrolytes solution

Herein, we have studied the mixed micellization of Cetyltrimethylammonium bromide (CTAB) and Sodium dodecyl sulfate (SDS), in aqueous/various salts medium at several temperatures (298.15–318.15 K) by conductivity measurement method. The extent of interaction between CTAB and SDS was assessed from the values of ideal critical micelle concentration (cmcid) as well as experimental cmc. In attendance of salts, cmc values are obviously decreased from the corresponding values in aqueous medium. The magnitudes of micellar mole fraction of CTAB (X1) and activity coefficients of CTAB & SDS (f1 &f2) were estimated based on different theoretical model and outcome disclose the effective involvement of CTAB in the mixed micellization. The executed values of both interaction parameters (β) and excess free energy of micellization were negative signifying the attractive interaction and stability of mixed micelles respectively. The executed negative values of Gibbs free energy change of micellization, ∆Gom illustrate the spontaneous micellization of individual/mixed surfactant system. The other thermodynamic parameters ΔHom (enthalpy change), and ∆Som (entropy change) were also calculated from the conventional standard equations. Molecular level interactions are disclosed by molecular dynamics (MD) simulation which showed that salts promote more interactions between the surfactants.

Solubilization of polycyclic aromatic hydrocarbons by novel ester-bonded Gemini prolinol-based surfactant and its binary mixtures with conventional surfactants

Aqueous interactions of a novel ester-bonded Gemini prolinol-based surfactant, 2,2′-((adipoylbis(oxy))bis(methylene))bis(1-dodecyl-1-methylpyrrolidin-1-ium) bromide C12-6-C12PB, with dodecyl sodium sulfate (SDS), dodecyl trimethyl ammonium bromide (DTAB), tetradecyl trimethyl ammonium bromide (TTAB), or cetyltrimethyl ammonium bromide (CTAB) were studied using conductomeric measurement. The experimental critical micelle concentration (CMC) was lower than the ideal CMC, and the negative interaction parameters indicate that there is a synergistic interaction between the surfactants in the binary solution. The solubilization capacities of single and binary surfactant systems towards polycyclic aromatic hydrocarbons (PAHs) (i.e., naphthalene, anthracene, and pyrene) were evaluated and are discussed in terms of the molar solubilization ratio (MSR), micelle-water partition coefficient (Km), and free energy of solubilization (). C12-6-C12PB and SDS respectively had the minimum and maximum MSR when presented individually in the solution. The MSR values in the binary system are greater than those in the single surfactant system, and this indicates that synergism in a mixed system enhances PAH solubility. With a molar ratio of 0.7:0.3, C12-6-C12PB/SDS had a relatively greater solubilization capacity for PAHs because of large aggregates. The negative value of indicates the spontaneity of the solubilization process.

Experimental and theoretical investigation of micellization behavior of sodium dodecyl sulfate with cetyltrimethylammonium bromide in aqueous/urea solution at various temperatures

Mixed micelle formation behavior of cationic surfactant-cetyltrimethylammonium bromide (CTAB) and anionic surfactant sodium dodecyl sulfate (SDS) in aqueous as well as in urea medium from 303.15 K to 323.15 K at 5 K interval was carried out by conductometric method. The differences between the experimental values of critical micelle concentrations (cmc) and ideal critical micelle concentrations (cmcid) illustrate the interaction between the amphiphiles studied. The values of micellar mole fraction ( $$\text{X}_1^{Rub}$$ (Rubingh), $$\text{X}_1^{M}$$ (Motomura), $$\text{X}_1^{Rod}$$ (Rodenas) and $$\text{X}_1^{id}$$ (ideal) of surfactant CTAB determined by different proposed models and outcome indicate high involvement of CTAB in SDS-CTAB mixed micellization, which enhance by means of the augment of mole fraction of CTAB. The negative value of interaction parameter (β) showed an attractive interaction involving CTAB and SDS. Activity coefficients were less than unity in all case, which also reveals the presence of interaction between CTAB & SDS. The negative $$\Delta{\text{G}}_m^0$$ values imply the spontaneous mixed micellization phenomenon. The attained values of $$\Delta{\text{H}}_m^0$$ were positive at inferior temperature, while negative at superior temperature. The negative $$\Delta{\text{H}}_m^0$$ values in urea (NH2CONH2) medium illustrate exothermic micellization process. The magnitudes of $$\Delta{\text{S}}_m^0$$ were positive in almost all cases. The excess free energy of mixed micelle formation (ΔGex) was found to be negative, which indicates the stability of mixed micelle as compared to the individual’s components micelles.

Association behavior of a mixed system of the antidepressant drug imipramine hydrochloride and dioctyl sulfosuccinate sodium salt: Effect of temperature and salt

Herein, we have checked the interaction between the imipramine hydrochloride (IMH, an antidepressant drug) and anionic surfactant dioctyl sulfosuccinate sodium salt (AOT) mixed system through a conductometric method in aqueous medium along with electrolyte solutions at different temperatures (288.15 to 303.15 K). Considerable changes were obtained in the different physicochemical parameters estimated in the current system. The AOT has an exceptional surface activity together with a very low critical micelle concentration (cmc) value as compared with other anionic surfactants, therefore, having much less toxicity. The deviations between observed cmc and ideal critical micelle concentration (cmcid) values point to an interaction between IMH and AOT. The value of cmc of the mixed system reduces through the increase of the mole fraction of AOT. With a rise in the temperature, the cmc value of pure IMH along with IMH–AOT mixtures increases first and then decreases with a further rise in the temperature. In the presence of 50 mmol·kg−1 NaCl, the observed cmc of the individual constituents along with IMH–AOT mixtures was clearly lower than that in an aqueous system. The micellar mole fraction values according to different proposed models X1Rub (Rubingh), X1Mot (Motomura), X1Rd (Rodenas) and X1ideal (ideal mole fraction) were estimated and the results obtained reveal the high contribution of AOT in the mixed micellization and the values increase through the rise in the mole fraction of AOT. At all studied temperatures the magnitudes of free energy of micellization (∆Gm0), interaction parameter (β) along with excess free energy (∆Gex) evaluated for the current studied system were obtained to be negative. The value of the activity coefficients (f1 and f2) were also computed by employing the method specified in the literatures. The negative values of enthalpy (ΔHm0) of the systems at lower temperature indicate the micellization is exothermic while at higher temperature negative values of ΔHm0 becomes positive, which means the micellization process becomes endothermic. The values of entropy (ΔSm0) were found to be positive in all cases. All of the estimated results imply a strong interaction among the studied constituents.

Formation of Mixed Micelles of the Environmentally Acceptable Oxy-Diester-Linked Gemini Surfactants with Brij 58

Abstract Three oxy-diester-linked cationic gemini surfactants (2,2′-[(oxybis(ethane-1,2-diyl))bis(oxy)]bis(N-alkyl-N,N-dimethyl-2-oxoethanaminium) dichloride, Cm-DEG-Cm (m = 12, 14, 16), were synthesized. The physicochemical properties of the gemini surfactants and their mixtures with Brij 58 were studied by surface tension measurements at various mole fractions and 30°C. The critical micelle concentration (CMC) of the gemini surfactants are smaller than that of their corresponding single-chain counterparts having the same number of carbon atoms in the hydrophobic tail versus polar head. At all investigated compositions, the experimentally obtained CMC values of the surfactant mixtures are smaller than the CMCideal (ideal CMC – CMC of the solution at ideal state); the lower CMC of the mixed systems compared to those the individual surfactants and the negative β values (for both the mixed micelles and monolayers) indicate a synergistic interaction among both the surfactant components. The interaction parameters (βm and βσ) of the mixed surfactant systems were evaluated by using theoretical models. Negative values of β imply an overall attractive force in the mixed state. Also, the free excess energy of mixing was found to be negative for all the systems.

Ionic Liquid Influenced Synergistic Interaction between Amitriptyline Hydrochloride and Cetyltrimethylammonium Bromide

The mixed micellization behavior of amitriptyline hydrochloride (AMT) with cetyltrimethylammonium bromide (CTAB) has been studied at different mole fractions in the presence of imidazolium based ionic liquid 1-butyl-3-methyl imidazolium hydrochloride (Bmim·Cl), by using electrical conductivity at different temperatures from 298 to 318 K. A shift in the Tmax value (i.e., the temperature at which the cmc value is maximized) has been observed with the rise in CTAB mole fraction. Synergistic interaction is explained by the deviations in critical micelle concentration (cmc) from an ideal critical micelle concentration (cmc*) and micellar mole fraction (Xm) from ideal micellar mole fraction (Xideal) values. The calculated thermodynamic parameters (viz., the standard Gibbs energy change, ΔGm°, the standard enthalpy change, ΔHm°, and the standard entropy change, ΔSm°) suggest the dehydration of hydrophobic part of the drug at higher temperatures in the case of AMT as well as in CTAB-AMT binary systems in the pres...

Mixed Micellization Between an Antidepressant Drug Imipramine Hydrochloride and Surfactants (Conventional/Gemini) at Different Temperatures and Compositions

The micellization behavior of an amphiphilic antidepressant drug imipramine hydrochloride (IMP) in the presence of a conventional (CTAB) and three gemini (16-s-16, s = 4–6) cationic surfactants has been studied at different temperatures and compositions by conductometry. The experimental and ideal critical micelle concentrations, cmc and cmc id, values indicate mixed micelle formation between the components. The micellar mole fractions of surfactants ( $$ X_{1}^{\text{Rub}} $$ , $$ X_{1}^{\text{M}} $$ , $$ X_{1}^{\text{Rod}} $$ and $$ X_{1}^{\text{id}} $$ ), calculated using different theoretical models, show greater contribution from the surfactants. The interaction parameter (β) is negative at all temperatures and at all compositions indicating attractive interactions. Activity coefficients (f 1 and f 2) are always less than unity reflecting nonideality in the systems. Thermodynamic parameters which were also evaluated suggest dehydration of the hydrophobic part of the drug at higher temperatures.

Effect of Sodium Taurocholate on Aggregation Behavior of Amphiphilic Drug Solution

AbstractThe aggregation behavior of promazine hydrochloride (PMZ) and bile salt (sodium taurocholate (NaTC)) mixtures at various compositions and temperature in pure and mixed states were studied using conductometry technique in aqueous solutions. The values of experimental and ideal critical micelle concentration (cmc and cmcid) propose attractive interactions in PMZ-NaTC mixtures. By applying the regular solution theory (RST) various physicochemical parameter such as micellar mole fraction in the mixed (X1) and ideal (X1id) state, interaction parameters (β), thermodynamic parameters of micellization as well as other related parameters have been evaluated and discussed in detail. The results show that the synergistic effect between drug and bile salt plays a crucial role in the redtdprefuction of the overall cmc value in aqueous solution at various composition of NaTC. The thermodynamic parameters recommend the discharge of water from the hydrophobic part of the PMZ at higher temperatures.