Discharge of the Nanopore Confinement Effect on the Glass Transition Dynamics via Viscous Flow

Using dielectric spectroscopy, we demonstrate that confinement-induced changes in the glass transition dynamics, as observed for polymethylphenylsiloxane in alumina nanopores, reveal a pronounced nonequilibrium nature. Our results indicate that glass formers confined to nanopores are able to recover their bulklike mobility. We found that the characteristic time constant of such an equilibration process correlates with an extremely slow viscous flow rate in cylindrical channels of nanometer size. Thus, all the way to equilibrium, confinement effects seen in faster segmental dynamics are released through the viscous flow which eventually helps to eliminate surplus volume gained by nanoconstrained polymers upon cooling.

Evidence of a one-dimensional thermodynamic phase diagram for simple glass-formers

Glass formers show motional processes over an extremely broad range of timescales, covering more than ten orders of magnitude, meaning that a full understanding of the glass transition needs to comprise this tremendous range in timescales. Here we report simultaneous dielectric and neutron spectroscopy investigations of three glass-forming liquids, probing in a single experiment the full range of dynamics. For two van der Waals liquids, we locate in the pressure-temperature phase diagram lines of identical dynamics of the molecules on both second and picosecond timescales. This confirms predictions of the isomorph theory and effectively reduces the phase diagram from two to one dimension. The implication is that dynamics on widely different timescales are governed by the same underlying mechanisms.

Comparison of high pressure and nanoscale confinement effects on crystallization of the molecular glass-forming liquid, dimethyl phthalate

High pressure and nanoscopic confinement are two different strategies commonly employed to modify the physicochemical properties of various materials. Both strategies act mostly by changing the molecular packing. In this work, we performed a comparative study on the effect of compression and confined geometry on crystallization of a molecular liquid. Dielectric spectroscopy was employed to investigate the crystallization of the van der Waals liquid, dimethyl phthalate, in nanoporous alumina of different pore sizes as well as on increased pressure (up to 200 MPa). The analysis of the crystallization kinetics under varying thermodynamic conditions revealed that both strategies affect the crystallization behavior of the sample in very distinct ways. Compression shifts the maximum crystallization rate towards a higher temperature and broadens it. As a result, it is more challenging to avoid crystallization upon cooling the liquid at high pressure. In contrast, when the same material is incorporated into nanopores, crystallization significantly slows down and the maximum rate shifts towards a lower temperature with decreasing pore size. Finally, we show that crystallization in nanoporous alumina is accompanied by pre-crystallization effects upon which a shift of the α-relaxation peak is observed. An equilibration process prior to the initiation of crystallization was detected for the confined material both above and below the glass transition temperature of the interfacial layer, while not in the bulk.

Formation of new polymorphs and control of crystallization in molecular glass-formers by electric field

We show that an electric field is able to modify the crystallization tendency of a low-molecular weight glass-forming liquid.

The effect of hydrogen bonding propensity and enantiomeric composition on the dynamics of supercooled ketoprofen - dielectric, rheological and NMR studies

The aim of this work is to analyze in detail the effect of small hydrogen bonding (HB) structures and enantiomeric composition on the dynamics of glass-forming liquid ketoprofen. For that purpose dielectric relaxation, rheological and NMR studies were performed. Investigated samples are racemic ketoprofen, a single enantiomer of ketoprofen and a racemic ketoprofen methyl ester with no tendency to form HB dimers. The combination of complementary experimental techniques enables us to show that macroscopic viscosity η and α-relaxation time τα have nearly the same temperature dependencies, whereas the relation between the viscosity (or molecular reorientation) and the translational self-diffusion coefficient violates Stokes-Einstein law already at high temperature. Additionally, based on dielectric relaxation studies performed on increased pressure we were able to identify similarities and key differences in the supercooled liquid dynamics of investigated materials affected by their tendency to form intermolecular hydrogen bonds. This includes the effect of pressure on the glass transition temperature Tg, changes in the fragility parameter m and activation volume ΔV, the role of thermal energy and density fluctuations in governing the viscous liquid dynamics (Ev/Ep ratio). Finally, we have also demonstrated that the dynamic behaviour of a single enantiomer and the racemic mixture of the same compound are very much alike. Nevertheless, some slight differences were observed, particularly in the τα(T) dependencies measured in the vicinity of glass transition both at ambient and elevated pressure.

Isochronal superposition and density scaling of the intermolecular dynamics in glass-forming liquids with varying hydrogen bonding propensity

We have tested the idea of thermodynamic scaling T⁻¹ρ^γ and isochronal superposition in glass-forming liquids with varying propensity to form hydrogen bonds.

Negative Pressure Vitrification of the Isochorically Confined Liquid in Nanopores

Dielectric relaxation studies for model glass-forming liquids confined to nanoporous alumina matrices were examined together with high-pressure results. For confined liquids which show the deviation from bulk dynamics upon approaching the glass transition (the change from the Vogel-Fulcher-Tammann to the Arrhenius law), we have observed a striking agreement between the temperature dependence of the α-relaxation time in the Arrhenius-like region and the isochoric relaxation times extrapolated from the positive range of pressure to the negative pressure domain. Our finding provides strong evidence that glass-forming liquid confined to native nanopores enters the isochoric conditions once the mobility of the interfacial layer becomes frozen in. This results in the negative pressure effects on cooling. We also demonstrate that differences in the sensitivity of various glass-forming liquids to the "confinement effects" can be rationalized by considering the relative importance of thermal energy and density contributions in controlling the α-relaxation dynamics (the E(v)/E(p) ratio).

Thermodynamic scaling of molecular dynamics in supercooled liquid state of pharmaceuticals: Itraconazole and ketoconazole

Pressure-Volume-Temperature (PVT) measurements and broadband dielectric spectroscopy were carried out to investigate molecular dynamics and to test the validity of thermodynamic scaling of two homologous compounds of pharmaceutical activity: itraconazole and ketoconazole in the wide range of thermodynamic conditions. The pressure coefficients of the glass transition temperature (dT(g)/dp) for itraconazole and ketoconazole were determined to be equal to 183 and 228 K/GPa, respectively. However, for itraconazole, the additional transition to the nematic phase was observed and characterized by the pressure coefficient dT(n)/dp = 258 K/GPa. From PVT and dielectric data, we obtained that the liquid-nematic phase transition is governed by the relaxation time since it occurred at constant τ(α) = 10(-5) s. Furthermore, we plotted the obtained relaxation times as a function of T(-1)v(-γ), which has revealed that the validity of thermodynamic scaling with the γ exponent equals to 3.69 ± 0.04 and 3.64 ± 0.03 for itraconazole and ketoconazole, respectively. Further analysis of the scaling parameter in itraconazole revealed that it unexpectedly decreases with increasing relaxation time, which resulted in dramatic change of the shape of the thermodynamic scaling master curve. While in the case of ketoconazole, it remained the same within entire range of data (within experimental uncertainty). We suppose that in case of itraconazole, this peculiar behavior is related to the liquid crystals' properties of itraconazole molecule.

Enhancement of the physical stability of amorphous indomethacin by mixing it with octaacetylmaltose. inter and intra molecular studies

PURPOSE

To demonstrate a very effective and easy way of stabilization of amorphous indomethacin (IMC) by preparing binary mixtures with octaacetylmaltose (acMAL). In order to understand the origin of increased stability of amorphous system inter- and intramolecular interactions between IMC and acMAL were studied.

METHODS

The amorphous IMC, acMAL and binary mixtures (IMC-acMAL) with different weight ratios were analyzed by using Dielectric Spectroscopy (DS), Differential Scanning Calorimetry (DSC), Raman Spectroscopy, X-ray Diffraction (XRD), Infrared Spectroscopy (FTIR) and Quantitative Structure-Activity Relationship (QSAR).

RESULTS

Our studies have revealed that indomethacin mixed with acetylated saccharide forms homogeneous mixture. Interestingly, even a small amount of modified maltose prevents from recrystallization of amorphous indomethacin. FTIR measurements and QSAR calculations have shown that octaacetylmaltose significantly affects the concentration of indomethacin dimers. Moreover, with increasing the amount of acMAL in the amorphous solid dispersion molecular interactions between matrix and API become more dominant than IMC-IMC ones. Structural investigations with the use of X-ray diffraction technique have demonstrated that binary mixture of indomethacin with acMAL does not recrystallize upon storage at room temperature for more than 1.5 year. Finally, it was shown that acMAL can be used to improve solubility of IMC.

CONCLUSIONS

Acetylated derivative of maltose might be very effective agent to improve physical stability of amorphous indomethacin as well as to enhance its solubility. Intermolecular interactions between modified carbohydrate and IMC are likely to be responsible for increased stability effect in the glassy state.

Molecular dynamics of itraconazole at ambient and high pressure

Comprehensive molecular dynamics studies of vitrified and cryogrounded itraconazole (Itr) were performed at ambient and elevated pressure. DSC measurements yielded besides melting and glass transition observed during heating and cooling of both samples two further endothermic events at around T = 363 K and T = 346 K. The nature of these transitions was investigated using X-ray diffraction, broadband dielectric spectroscopy and Density Functional Theory calculations. The X-ray measurements indicated that extra ordering in itraconazole is likely to occur. Based on calculations and theory derived by Letz et al. the transition observed at T = 363 K was discussed in the context of formation of the nematic mesophase. In fact, additional FTIR measurements revealed that order parameter variation in Itr shows a typical sequence of liquid crystal phases with axially symmetric orientational order; i.e. a nematic phase in the temperature range 361.7 K to 346.5 K and a smectic A phase below 346.5. Moreover, dielectric measurements demonstrated that except for the structural relaxation process, there is also slower mode above the glass transition temperature in both vitrified and cryogrounded samples. We considered the origin of this mode taking into account DFT calculations, rod like shape of itraconazole and distribution of its dipole moment vectors. For the dielectric data collected at elevated pressure, evolution of the steepness index versus pressure was determined. Finally, the pressure coefficient of the glass transition temperature was evaluated to be equal to 190 K GPa(-1).

Mutarotation in biologically important pure L-fucose and its enantiomer

The sugar specific mutarotation reaction in biologically important L-fucose and its enantiomer in the pure, anhydrous, supercooled liquid state has been studied. Kinetics measurements in the temperature range 313-328 K at ambient pressure have been performed by means of dielectric spectroscopy, a method widely used for studying the molecular dynamics of glass-forming liquids. The kinetic curves have been obtained by tracking the equilibration process in sugar melted and quenched to the desired temperature. Thereafter, an activation energy equal to Ea = 140 kJ mol(-1) for D-fucose and Ea = 123 kJ mol(-1) for L-fucose has been derived from the Arrhenius fit of temperature dependent rate constants. It was also shown that the kinetics curves at the lowest temperatures studied have sigmoidal shape, which was connected to the high concentration of furanosidic forms.

A new way of stabilization of furosemide upon cryogenic grinding by using acylated saccharides matrices. The role of hydrogen bonds in decomposition mechanism

Recently it was reported that upon mechanical milling of pure furosemide significant chemical degradation occurs (Adrjanowicz et al. Pharm. Res.2011, 28, 3220-3236). In this paper, we present a novel way of chemical stabilization amorphous furosemide against decomposing that occur during mechanical treatment by preparing binary mixtures with acylated saccharides. To get some insight into the mechanism of chemical degradation of furosemide induced by cryomilling, experimental investigations supported by density functional theory (DFT) computations were carried out. This included detailed studies on molecular dynamics and physical properties of cryoground samples. The main thrust of our paper is that we have shown that furosemide cryomilled with acylated saccharides forms chemically and physically stable homogeneous mixtures with only one glass transition temperature, Tg. Finally, solubility measurements have demonstrated that furosemide cryomilled with acylated saccharides (glucose, maltose and sucrose) is much more soluble with respect to the crystalline form of this active pharmaceutical ingredient (API).

Impact of water on molecular dynamics of amorphous α-, β-, and γ-cyclodextrins studied by dielectric spectroscopy

Dielectric, calorimetric, and x-ray diffraction measurements were carried out on α-, β-, and γ-cyclodextrins, which are cyclic saccharides built by, respectively, six, seven, and eight glucose units connected via glycosidic linkage. Differential scanning calorimetry measurements indicated that each carbohydrate has a melting temperature located much above the temperature at which thermal decomposition begins. Moreover, calorimetric data revealed that it is possible to completely dehydrate each cyclodextrin by annealing them above 413 K. Unfortunately, it is impossible to obtain amorphous forms of cyclodextrin by simple cooling of the melt. Thus, a solid state amorphization method has been applied. X-ray diffraction studies demonstrated that by ball milling at room temperature we are able to obtain completely amorphous cyclodextrins. Finally, dielectric measurements were carried out to probe molecular dynamics in the amorphous state of cyclodextrins. It was found that there is only one relaxation process in amorphous hydrated cyclodextrins, while in dried samples two secondary relaxations are present. Moreover, we have shown that water has an enormous effect on the dynamics of both relaxation modes, i.e., with increasing content of water, the activation energy of the slow mode decreases, while that evaluated for the fast mode increases. We were not able to follow the dynamics of the structural relaxation process, because glass transition temperatures of amorphous cyclodextrins were found to lie above thermal degradation points.

The importance of the activation volume for the description of the molecular dynamics of glass-forming liquids

High pressure dielectric measurements were carried out on hydrogen bonded d-glucose and two van der Waals peracetyl saccharides, i.e. α pentaacetyl glucose and α octaacetyl maltose. In this study we found that after removing H bonds, the molecular dynamics of both modified saccharides is very sensitive to pressure, as reflected by a large value of the pressure coefficient of the glass transition temperature, equal to 270 K GPa(-1) and 280 K GPa(-1) for α pentaacetyl glucose and α octaacetyl maltose, respectively. On the other hand, dT(g)/dP for d-glucose is much lower, equal to 67 K GPa(-1). Our result confirms the general rule that the hydrogen bonding glass-forming liquids exhibit much lower values of dT(g)/dP compared to the van der Waals systems. Additionally, on the basis of results reported herein and also recent literature data for polyalcohols, we point out that the activation volume correlates fairly well with the molecular volume in the case of hydrogen bonding liquids. On the other hand, much larger values of the activation volumes at T(g) with respect to the molecular volumes were found for both peracetyl saccharides.

Molecular dynamics and crystallization phenomenon of supercooled and glassy DNA and RNA nucleosides: β-adenosine, β-thymidine, and β-uridine

Nucleosides are chemical compounds that have an extremely important biological role; they can be found in all types of living organisms. They are crucial components from which DNA and RNA acids are built. In addition, nucleosides are key regulators of many physiological processes. In this paper, the molecular dynamics in the liquid and glassy state of three selected nucleosides, β-adenosine, β-thymidine, and β-uridine, was investigated by means of dielectric spectroscopy. Our results revealed multiple relaxation processes associated with different types of molecular motions. Besides the primary α relaxation, two secondary modes in the glassy states of examined compounds were identified. Crystallization progress monitored by dielectric spectroscopy and x-ray diffraction technique at isostructural relaxation conditions revealed that the examined nucleosides possess completely different tendencies to recrystallize from the liquid as well as the glassy state. We have also made an attempt to predict the time scale of molecular motion below the glass transition temperatures of the respective nucleosides to discuss their potential stability at room temperature over prolonged storage time. Finally, combination of molecular mobility studies with evaluation of thermodynamic parameters from calorimetric measurements allowed us to discuss the fundamental roles of both kinetic and thermodynamic factors in governing the physical stability of the glassy state.

Do intermolecular interactions control crystallization abilities of glass-forming liquids?

Broadband dielectric spectroscopy was used to investigate molecular dynamics of three very similar systems: D-glucose, α-pentaacetylglucose, and β-pentaacetylglucose in a wide range of temperatures. We found out that two latter systems (differing only in location of the acetyl group attached to the first carbon in the sugar ring) reveal completely opposite tendencies to crystallization. Therefore, the aim of this Article was to investigate in detail molecular dynamics of both pentaacetylglucoses to assess what are the underlying of different crystallization abilities of so closely related carbohydrates. To analyze the kinetics of crystallization, we used Avrami and Avramov approaches. Interestingly, we found out that both α-and β-pentaacetylglucose exhibit completely different crystallization mechanisms. In the first case, the value of Avrami exponent was estimated to be n = 2, whereas for the second carbohydrate this exponent was equaled to n = 5.5. Additionally, we have carried out isothermal time-dependent dielectric measurements on D-glucose to demonstrate that this saccharide is more stable than its acetyl derivatives. Results presented in this Article indicate that besides molecular mobility, the character of the intermolecular interactions might also be another important factor governing crystallization process. Surprisingly, this issue is not often addressed during studies on crystallization abilities of different glass-formers. Finally, additional optical measurements were carried out to get more detailed information about nucleation density, activation barrier for a crystal growth, and morphology of crystallization structures.

Comparative dielectric studies on two hydrogen-bonded and van der Waals liquids

Broadband dielectric measurements were performed in a wide range of temperatures on glucose, maltose, and their acetyl derivatives. We have indicated that molecular dynamics above and below the glass transition temperature differ considerably for the hydrogen-bonded and van der Waals systems. We have shown that structural relaxation dispersions of D-glucose and maltose are broader than those obtained for peracetyl carbohydrates. Moreover, glass transition temperatures of the former systems are much higher than for the latter ones. In the glassy state of both glucose and its acetyl derivatives only one well-separated secondary relaxation process was identified. In the case of maltose and peracetyl maltose a completely different situation was observed. In the former carbohydrate two secondary modes were detected, whereas in the latter one only a faster relaxation process was visible in the glassy state. This finding is discussed in greater detail on the basis of density functional theory calculations.

Probing of structural relaxation times in the glassy state of sucrose and trehalose based on dynamical properties of two secondary relaxation processes

Time-dependent isothermal dielectric measurements were carried out deeply in the glassy state on two very important saccharides: sucrose and trehalose. In both compounds two prominent secondary relaxation processes were identified. The faster one is an inherent feature of the whole family of carbohydrates. The slower one can also be detected in oligo- and polysaccharides. It was shown earlier that the β process is the Johari-Goldstein (JG) relaxation coupled to motions of the glycosidic linkage, while the γ relaxation originates from motions of the exocyclic hydroxymethyl unit. Recently, it was shown that the JG relaxation process can be used to determine structural relaxation times in the glassy state [R. Casalini and C. M. Roland, Phys. Rev. Lett. 102, 035701 (2009)]. In this paper we present the results of an analysis of the data obtained during aging using two independent approaches. The first was proposed by Casalini and Roland, and the second one is based on the variation of the dielectric strength of the secondary relaxation process during aging [J. K. Vij and G. Power, J. Non-Cryst. Solids 357, 783 (2011)]. Surprisingly, we found that the estimated structural relaxation times in the glassy state of both saccharides are almost the same, independent of the type of secondary mode. This finding calls into question the common view that secondary modes of intramolecular origin do not provide information about the dynamics of the glassy state.

Molecular dynamics of the cryomilled base and hydrochloride ziprasidones by means of dielectric spectroscopy

Cryomilling was applied to obtain amorphous forms of the base ziprasidone and its hydrochloride salt. Complete amorphization of both samples was confirmed by differential scanning calorimetry and X-ray measurements. As it turned out, cryogrinding is very effective way to obtain these drugs in the amorphous state, especially because melting of both ziprazidones accompanies significant chemical decomposition as revealed by ultra performance liquid chromatography examination. Consequently, the glassy state cannot be reached in conventional way, that is, by supercooling of melt. Broadband dielectric relaxation measurements were performed on both drugs to describe their molecular dynamics above as well as below their glass transition temperatures (T(g)). We found out that ziprasidone base and its hydrochloride salt differ in T(g) in the same way as it was previously reported for tramadol monohydrate and its hydrochloride. Moreover, our dielectric studies revealed that molecular mobility is not the main factor controlling kinetics of crystallization of both ziprasidones above their T(g) . Below the T(g) relaxation related to water as well as secondary relaxation process originating from the intermolecular interaction (Johari-Goldstein) were identified in the loss spectra of both materials. We have demonstrated that except of local mobility, water is the dominant factor moving both ziprasidones toward recrystallization process. Finally, we have also carried out solubility measurements to show that dissolution rate of the amorphous ziprasidones is much higher with respect to the crystalline samples.

Dielectric relaxation study on tramadol monohydrate and its hydrochloride salt

Dielectric relaxation measurements as well as differential scanning calorimetry and X-ray diffraction investigations were performed on tramadol monohydrate and its hydrochloride salt. Examined samples do not crystallize during cooling and in consequence they reach the glassy state. In the case of the hydrochloride tramadol we are able to monitor alpha-relaxation process despite large contribution of dc conductivity to the loss spectra. It is the first such study on the salt of the drug. Up to now the dielectric spectroscopy has been regarded as useless in measuring such kind of API (active pharmaceutical ingredient). In this paper we also made some suggestions about the nature of the secondary relaxations in the amorphous tramadol monohydrate and its salt. The knowledge about the molecular mechanisms, which govern the observed secondary relaxations seems to be the key in predicting the stability of the amorphous form of the examined API. Finally additional dissolving measurements on the amorphous and crystal tramadol hydrochloride were performed. As a result we understood that dissolution properties of the amorphous form of the considered drug are comparable to those of crystalline one. However, we have found out that amorphous tramadol hydrochloride has greater ability to form tablets than its crystalline equivalent. This finding shows that amorphous drugs can be alternative even for the freely solved pharmaceuticals such as tramadol hydrochloride, because the former one has better ability to form tablets. It implies that during tabletting of the amorphous drugs there is no need to use any excipients and chemicals improving compaction properties of the API.

Dynamics of the slow mode in the family of six-carbon monosaccharides monitored by dielectric spectroscopy

Broadband dielectric measurements performed on D-glucose, L-sorbose, D-fructose and D-galactose revealed that, except for the structural relaxation process, one can detect in the liquid phase of these carbohydrates a much slower relaxation mode. Recently we have demonstrated that in D-glucose this relaxation mode might be related to the long range correlation of density fluctuations (LRCDF), also called Fischer clusters (FC). Based on the dielectric data obtained for the four monosaccharides we were able to make a more general conclusion about the characteristic dielectric features of the slow mode in the whole family of carbohydrates. We found out that the timescale separation between structural and considered relaxation reaches up to six decades at the glass transition temperature and the dielectric strength decreases significantly with lowering temperature. Another very interesting feature of the slow process is that it can be described by an almost exponential response function. We have found out that the fragility of the slow process lies within the range m = 44-50. Finally, we have also shown that there is a close link between structural and slow relaxation.

Study of the amorphous glibenclamide drug: analysis of the molecular dynamics of quenched and cryomilled material

Glibenclamide (GCM) is an oral hypoglycemic agent of the sulfonylurea group used in the treatment of non-insulin-dependent diabetes. Crystalline GCM is characterized by low bioavailability, which is attributed to its poor dissolution properties. It prompted us to prepare this drug in its amorphous form as a means to enhance its dissolution characteristics. Two different methods were used to convert crystalline GCM into the glassy form: quench-cooling of the melt and cryogenic milling. To monitor solid-state properties of the amorphous samples, X-ray powder diffraction (XRD), infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), ultraperformance liquid chromatography (UPLC) and spectroscopy, and broadband dielectric spectroscopy (BDS) were applied. The results of UPLC separations along with associated infrared and NMR measurements unambiguously showed that the thermal degradation of the quenched GCM, as suggested in literature reports, does not occur. A similar analysis performed on the cryomilled material also did not indicate any chemical decomposition. On the other hand, both methods confirmed that the conversion to the amorphous form is connected with the amide-imidic acid tautomerism of the examined drug. Moreover it was shown that this transformation occurs regardless of the manner of amorphization. Finally, dielectric spectroscopy was employed to study the molecular dynamics of vitrified GCM. The analysis of the ε''(f) in terms of the KWW function from the dielectric measurements revealed the existence of an "excess wing" attributed to the true Johari-Goldstein process based on Ngai's coupling model. The dielectric properties of GCM obtained in the amorphous form both by rapid cooling of the melt and the cryogenic grinding of crystalline sample were also compared.

Determining the structural relaxation times deep in the glassy state of the pharmaceutical Telmisartan

By using the dielectric relaxation method proposed recently by Casalini and Roland (2009 Phys. Rev. Lett. 102 035701), we were able to determine the structural α-relaxation times deep in the glassy state of the pharmaceutical, Telmisartan. Normally, deep in the glassy state τ(α) is so long that it cannot be measured but τ(β), which is usually much shorter, can be directly determined. The method basically takes advantage of the connection between the α-relaxation and the secondary β-relaxation of the Johari-Goldstein kind, including a relation between their relaxation times τ(α) and τ(β), respectively. Thus, τ(α) of Telmisartan were determined by monitoring the change of the dielectric β-loss, ε'', with physical aging time at temperatures well below the vitrification temperature. The values of τ(α) were compared with those expected by the coupling model (CM). Unequivocal comparison cannot be made in the case of Telmisartan because its β-loss peak is extremely broad, and the CM predicts only an order of magnitude agreement between the primitive relaxation frequency and the β-peak frequency. We also made an attempt to analyze all isothermal and aging susceptibility data after transformation into the electric modulus representation. The τ(α) found in the glass state by using the method of Casalini and Roland in the modulus representation are similar to those obtained in the susceptibility representation. However, it is remarkable that the stretching parameter β(KWW - M) = 0.51 in the electric modulus representation gives more precise fits to the aging data than in the susceptibility representation with β(KWW) = 0.61. Our results suggest that the electric modulus representation may be useful as an alternative to analyze aging data, especially in the case of highly polar glassformers having a large ratio of low frequency and high frequency dielectric constants, such as the Telmisartan studied.