Ternary amorphous composites of celecoxib, poly(vinyl pyrrolidone) and meglumine with enhanced solubility

The present study highlights the development of ternary amorphous composites to enhance the solubility of a poorly soluble crystalline drug, celecoxib (CEL). These systems comprised of an 'amorphous drug,' and its 'stabilizer' and 'solubilizer.' The ternary amorphous system of CEL, poly(vinyl pyrrolidone) (PVP) and meglumine (MEG) (7:2:1 w/w) enhanced CEL solubility by approximately equal to 10.2-fold over that for the crystalline drug, and maintained the thermodynamic stability of the amorphous drug. However, MEG alone was unable to stabilize the amorphous CEL against thermally-induced crystallization, and so gave no solubility advantage. The PVP-MEG combination provided a 'synergistic' enhancement of CEL solubility, as compared to their use alone in the amorphous systems. Phase-solubility studies provided greater insight into molecular mechanisms underlying stability and solubility of these amorphous systems. MEG exhibited phase-specific interaction with CEL molecules, when stabilized by PVP in the amorphous state. The higher solubility of CEL from ternary amorphous systems was also thermodynamically favored, as analyzed by van't Hoff plots. A possible molecular level interaction of MEG with PVP-stabilized amorphous CEL seems to be responsible for the solubility advantage of the CEL-PVP-MEG ternary amorphous system.     

Modeling of drug release from celecoxib-PVP-meglumine amorphous systems

An empirical assessment of drug release from amorphous systems of celecoxib (CEL), poly(vinyl pyrrolidone) (PVP), and meglumine (MEG) was performed and compared with that for its crystalline form. CEL-PVP (4:1 w/w) binary and CEL-PVP-MEG (7:2:1 w/w) ternary amorphous systems provided higher drug dissolution. Mathematical modeling of drug release data was found to best fit the Hixson-Crowell release model. The biphasic drug release during a 6-h duration exhibited higher release kinetics in the first phase due to the presence of drug in amorphous form. The release kinetics subdued in the latter phase due to ongoing devitrification process in amorphous systems. A comprehensive understanding of drug release from amorphous systems will accentuate the rationalized design of amorphous drug delivery systems.     

Improved physical stability of amorphous state through acid base interactions

To investigate role of specific interactions in aiding formation and stabilization of amorphous state in ternary and binary dispersions of a weakly acidic drug. Indomethacin (IMC), meglumine (MU), and polyvinyl pyrollidone (PVP) were the model drug, base, and polymer, respectively. Dispersions were prepared using solvent evaporation. Physical mixtures were cryogenically coground. XRPD, PLM, DSC, TGA, and FTIR were used for characterization. MU has a high crystallization tendency and is characterized by a low T(g) (17 degrees C). IMC crystallization was inhibited in ternary dispersion with MU compared to IMC/PVP alone. An amorphous state formed readily even in coground mixtures. Spectroscopic data are indicative of an IMC-MU amorphous salt and supports solid-state proton transfer. IMC-MU salt displays a low T(g) approximately 50 degrees C, but is more physically stable than IMC, which in molecular mixtures with MU, resisted crystallization even when present in stoichiometric excess of base. This is likely due to a disrupted local structure of amorphous IMC due to specific interactions. IMC showed improved physical stability on incorporating MU in polymer, in spite of low T(g) of the base indicating that chemical interactions play a dominant role in physical stabilization. Salt formation could be induced thermally and mechanically.     

Stability and Solubility of Celecoxib-PVP Amorphous Dispersions: A Molecular Perspective

PURPOSE: The purpose of the current study is to evaluate the solubility advantage offered by celecoxib (CEL) amorphous systems and to characterize and correlate the physical and thermodynamic properties of CEL and its amorphous molecular dispersions containing poly(vinylpyrrolidone) (PVP). METHODS: The measurement of crystalline content, glass transition temperatures, and enthalpy relaxation was performed using differential scanning calorimetry. Solubility and dissolutions studies were conducted at 37 degrees C to elucidate release mechanisms. Further, the amorphous systems were characterized by polarized light microscopy and X-ray powder diffraction studies. RESULTS: The PVP content has a prominent effect on the stability and solubility profiles of amorphous systems. A dispersion of 20% w/w PVP with CEL resulted in a maxima in terms of solubility enhancement and lowering of relaxation enthalpy. The release of drug from amorphous molecular dispersions was found to be drug-dependent and independent of the carrier. CONCLUSIONS: The solubility enhancement and enthalpy relaxation studies with respect to PVP concentration helped in a better prediction of role of carrier and optimization of concentration in the use of solid dispersions or amorphous systems. The drug release mechanism is drug-controlled rather than carrier-controlled.     

Amorphous Stabilization and Dissolution Enhancement of Amorphous Ternary Solid Dispersions: Combination of Polymers Showing Drug–Polymer Interaction for Synergistic Effects

The purpose of this study was to understand the combined effect of two polymers showing drug–polymer interactions on amorphous stabilization and dissolution enhancement of indomethacin (IND) in amorphous ternary solid dispersions. The mechanism responsible for the enhanced stability and dissolution of IND in amorphous ternary systems was studied by exploring the miscibility and intermolecular interactions between IND and polymers through thermal and spectroscopic analysis. Eudragit E100 and PVP K90 at low concentrations (2.5%–40%, w/w) were used to prepare amorphous binary and ternary solid dispersions by solvent evaporation. Stability results showed that amorphous ternary solid dispersions have better stability compared with amorphous binary solid dispersions. The dissolution of IND from the ternary dispersion was substantially higher than the binary dispersions as well as amorphous drug. Melting point depression of physical mixtures reveals that the drug was miscible in both the polymers; however, greater miscibility was observed in ternary physical mixtures. The IR analysis confirmed intermolecular interactions between IND and individual polymers. These interactions were found to be intact in ternary systems. These results suggest that the combination of two polymers showing drug–polymer interaction offers synergistic enhancement in amorphous stability and dissolution in ternary solid dispersions. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:3511–3523, 2014     

Barrier coated drug layered particles for enhanced performance of amorphous solid dispersion dosage form

Amorphous solid dispersions (ASDs) may entail tailor-made dosage form design to exploit their solubility advantage. Surface phenomena dominated the performance of amorphous celecoxib solid dispersion (ACSD) comprising of amorphous celecoxib (A-CLB), polyvinylpyrrolidone, and meglumine (7:2:1, w/w). ACSD cohesive interfacial interactions hindered its capsule dosage form dissolution (Puri V, Dhantuluri AK, Bansal AK 2011. J Pharm Sci 100:2460-2468). Furthermore, ACSD underwent significant devitrification under environmental stress. In the present study, enthalpy relaxation studies revealed its free surface to contribute to molecular mobility. Based on all these observations, barrier coated amorphous CLB solid dispersion layered particles (ADLP) were developed by Wurster process, using microcrystalline cellulose as substrate and polyvinyl alcohol (PVA), inulin, and polyvinyl acetate phthalate (PVAP) as coating excipients. Capsule formulations of barrier coated-ADLP could achieve rapid dispersibility and high drug release. Evaluation under varying temperature and RH conditions suggested the crystallization inhibitory efficiency in order of inulin < PVA ≈ PVAP; however, under only temperature treatment, crystallization inhibition increased with increase in T(g) of the coating material. Simulated studies using DSC evidenced drug-polymer mixing at the interface as a potential mechanism for surface stabilization. In conclusion, surface modification yielded a fast dispersing robust high drug load ASD based dosage form.     

Role of molecular interaction in stability of celecoxib-PVP amorphous systems

Stabilization of an amorphous solid against devitrification can be achieved using additives that interact specifically with the parent molecule, and restrain it from rearranging into a crystal lattice. The amorphous form of celecoxib (CEL) was stabilized by poly(vinylpyrrolidone) (PVP), both in the solid state and during dissolution. A comprehensive characterization of CEL-PVP binary amorphous systems by thermal, spectroscopic, and computer simulation techniques provided greater insight into the molecular interaction between the two species. PVP antiplasticized the amorphous CEL, thus raising its glass transition temperature (T(g)) and restricting the molecular mobility. The T(g)()mix values for CEL-PVP binary amorphous systems of varying composition showed positive deviation from those predicted through the Gordon-Taylor/ Kelley-Bueche equation, thus indicating a molecular interaction between CEL and PVP. This was further substantiated by shifts observed in DSC melting endotherms of CEL, and FTIR bands for C=O stretching vibrations in PVP for CEL-PVP binary amorphous systems. Computer simulation showed stronger H-bonds between amido protons of CEL and carbonyl O of a monomeric unit of PVP, compared to those observed in pure amorphous CEL. These molecular interactions between CEL and PVP supported the stabilizing action of PVP for the amorphous form of CEL.     

Development of spray-dried co-precipitate of amorphous celecoxib containing storage and compression stabilizers

The purpose of this study was to obtain an amorphous system with minimum unit operations that will prevent recrystallization of amorphous drugs since preparation, during processing (compression) and further storage. Amorphous celecoxib, solid dispersion (SD) of celecoxib with polyvinyl pyrrollidone (PVP) and co-precipitate with PVP and carrageenan (CAR) in different ratios were prepared by the spray drying technique and compressed into tablets. Saturation solubility and dissolution studies were performed to differentiate performance after processing. Differential scanning calorimetry and X-ray powder difraction revealed the amorphous form of celecoxib, whereas infrared spectroscopy revealed hydrogen bonding between celecoxib and PVP. The dissolution profile of the solid dispersion and co-precipitate improved compared to celecoxib and amorphous celecoxib. Amorphous celecoxib was not stable on storage whereas the solid dispersion and co-precipitate powders were stable for 3 months. Tablets of the solid dispersion of celecoxib with PVP and physical mixture with PVP and carrageenan showed better resistance to recrystallization than amorphous celecoxib during compression but recrystallized on storage. However, tablets of co-precipitate with PVP and carageenan showed no evidence of crystallinity during stability studies with comparable dissolution profiles. This extraordinary stability of spray-dried co-precipitate tablets may be attributed to the cushioning action provided by the viscoelastic polymer CAR and hydrogen bonding interaction between celecoxib and PVP. The present study demonstrates the synergistic effect of combining two types of stabilizers, PVP and CAR, on the stability of amorphous drug during compression and storage as compared to their effect when used alone.     

Spray Drying for Generation of a Ternary Amorphous System of Celecoxib,PVP, and Meglumine

Generation of amorphous forms of a poorly soluble drug by solid dispersion techniques has been a subject of intensive research for decades. Apart from the stability of the dispersions, development of a suitable production technology is a major challenge to the successful commercialization of these products. Coprocessing of celecoxib (CEL), poly(vinyl pyrrolidone), and meglumine by spray drying resulted in an amorphous drug product that provided enhanced solubility and stability to an otherwise poorly soluble crystalline form of CEL. The spray-drying process parameters were optimized to provide an amorphous product with required characteristics. The product was stable for 3 months under the accelerated stability storage conditions. This technique can serve as a suitable means for generating a ready-to-formulate amorphous drug-additive(s) composite that can be directly filled into hard gelatin capsules.     

Spray drying for generation of a ternary amorphous system of celecoxib, PVP, and meglumine

Generation of amorphous forms of a poorly soluble drug by solid dispersion techniques has been a subject of intensive research for decades. Apart from the stability of the dispersions, development of a suitable production technology is a major challenge to the successful commercialization of these products. Coprocessing of celecoxib (CEL), poly(vinyl pyrrolidone), and meglumine by spray drying resulted in an amorphous drug product that provided enhanced solubility and stability to an otherwise poorly soluble crystalline form of CEL. The spray-drying process parameters were optimized to provide an amorphous product with required characteristics. The product was stable for 3 months under the accelerated stability storage conditions. This technique can serve as a suitable means for generating a ready-to-formulate amorphous drug-additive(s) composite that can be directly filled into hard gelatin capsules.     

Preparation and structural characterization of amorphous spray-dried dispersions of tenoxicam with enhanced dissolution

Tenoxicam is a poorly soluble nonsteroidal anti-inflammatory drug. In this work, the solubility of tenoxicam is enhanced using amorphous spray-dried dispersions (SDDs) prepared using two molar equivalents of l-arginine and optionally with 10%-50% (w/w) polyvinylpyrrolidone (PVP). When added to the dispersions, PVP is shown to improve physical properties and also assists in maintaining supersaturation in solution. The dispersions provide a twofold increase over equilibrium solubility at the same pH. The dispersions are characterized using electron microscopy, vibrational spectroscopy, diffuse-reflectance visible spectroscopy, and X-ray powder diffraction. The structures of the dispersions are probed using solid-state nuclear magnetic resonance (SSNMR) experiments applied to the (1) H, (13) C, and (15) N nuclei, including two-dimensional dipolar correlation experiments that detect molecular association and the formation of a glass solution between tenoxicam, l-arginine, and PVP. Other aspects of the amorphous structure, including hydrogen-bonding interactions and the ionization state of tenoxicam and l-arginine, are also explored using SSNMR methods. These methods are used to show that the SDDs contain an amorphous l-arginine salt of tenoxicam in a glass solution that also includes PVP when present. Finally, the dispersions show only a minor decrease in chemical stability during accelerated stability studies relative to a crystalline form of tenoxicam.     

Investigation of atypical dissolution behavior of an encapsulated amorphous solid dispersion

Poor dissolution performance is one of the challenges encountered in dosage form design of amorphous solid dispersions (ASDs). This study was aimed to investigate the effect of solid-liquid interactions of an encapsulated ASD on drug release. Drug release profiles of a molecularly interacting amorphous celecoxib solid dispersion (ACSD) comprising of amorphous celecoxib (A-CLB), polyvinylpyrrolidone (PVP), and meglumine (7:2:1, w/w) were compared with crystalline CLB (C-CLB), in powder and capsule form. Although, ACSD powder displayed 28- to 50-fold higher dissolution efficiency at 60 min (DE(60)), the DE(60) in the encapsulated state were drastically reduced due to the formation of a nondispersible plug. The accompanied physical and compositional changes were investigated using X-ray powder diffraction, differential scanning calorimetry, scanning electron microscopy, and chromatographic techniques. ACSD displayed optimal wettability, sustained A-CLB-PVP interactions, and suppressed phase transformations in aqueous media. Furthermore, Fourier transform infrared and texture analysis revealed role of intermolecular interactions of the solid dispersion, which (i) altered PVP's functionality and (ii) promoted interparticle cohesivity via water-mediated hydrogen bonds, resulting in solid mass agglomeration. Parallel evaluation of A-CLB, physical mixture of ACSD components, and C-CLB solid dispersion supported the above inferences. On the basis of these findings, rationalized formulation approaches for ASD-based drug products are discussed.     

The influence of polyvinylpyrrolidone on naproxen complexation with hydroxypropyl-beta-cyclodextrin.

The combined effect of hydroxypropyl-beta-cyclodextrin (HPbetaCD) and polyvinylpyrrolidone (PVP) on the solubility of naproxen (NAP) was studied. Phase-solubility analysis at different temperatures was used to investigate interactions in aqueous solution between NAP and the carriers, either alone or in combination. Equimolar NAP-HPbetaCD solid systems, in the presence or the absence of 15% (w/w) PVP, were prepared by cogrinding, kneading, coevaporation or freeze-drying, and characterized by differential scanning calorimetry, X-ray powder diffraction analysis, infrared spectroscopy and dissolution rates. The combined use of PVP and HPbetaCD resulted in a synergistic increasing effect of the aqueous solubility of NAP (120 times that of the pure drug). The phenomenon was interpreted in terms of the strongest complexation capacity of HPbetaCD towards NAP, which was reflected by an about 65% increase in the apparent stability constant of the NAP-HPbetaCD complex in the presence of only 0.1% (w/v) PVP. Variations in thermodynamic parameters accounted for a PVP role in the formation of a NAP-HPbetaCD-PVP ternary complex. The positive effect of PVP also reflected on NAP dissolution rates from solid preparations, because all ternary systems, with the exception of physical mixtures, dissolved faster than the corresponding NAP-HPbetaCD binary systems. The results of solid state studies accounted for the occurrence of mechanically- and/or thermally-induced stronger interactions in ternary than in binary systems, that in some cases led to a complete loss of NAP crystallinity.     

Bioavailability enhancement of poorly water soluble and weakly acidic new chemical entity with 2-hydroxy propyl-beta-cyclodextrin: selection of meglumine, a polyhydroxy base, as a novel ternary component

The purpose of the present study was to investigate the influence of a polyhydroxy base, N-acetyl glucamine (also know as Meglumine), as a ternary component on the complexation of DRF-4367, a poorly water-soluble and weakly acidic anti-inflammatory molecule, with 2-hydroxypropyl-beta-cyclodextrin (HPbetaCD). The molecular inclusion of DRF-4367 with HPbetaCD alone and in combination with ternary component was aimed at improvement in solubility and, subsequently, dissolution rate-limited oral bioavailability. The solid complexes of DRF-4367 and HPbetaCD with or without meglumine (binary and ternary systems, respectively) were prepared as coevaporated product in different stoichiometric ratios and compared against physical mixture. The formation of inclusion complexes was confirmed by using classical instrumental techniques. Phase solubility studies suggested that meglumine was responsible for solubility improvement via multiple factors rather than just providing a favorable pH. Mechanisms and factors governing solubility enhancement were investigated by using phase solubility and thermodynamic parameters. The complexation of DRF-4367 with HPbetaCD is thermodynamically favored because the Gibbs free energies of transfer of the drug to the cyclodextrin cavity are negative. The solubilization efficiency and stability were further improved while retaining the favorable Gibbs free energies of transfer with the addition of meglumine. Inclusion ternary complex of DRF-4367 with HPbetaCD and meglumine showed significant improvement in dissolution compared with uncomplexed drug and binary system. Moreover, the phenomena of reprecipitation observed with binary system during dissolution could be avoided with meglumine as an enabling ternary component. This improved physicochemical behavior of ternary complex with the novel inclusion of a polyhydroxy base translated into an enhanced oral bioavailability of DRF-4367 compared with either uncomplexed drug or nanosuspension.     

Bioavailability Enhancement of Poorly Water Soluble and Weakly Acidic New Chemical Entity with 2-Hydroxy Propyl-β-Cyclodextrin: Selection of Meglumine,a Polyhydroxy Base,as a Novel Ternary Component

The purpose of the present study was to investigate the influence of a polyhydroxy base, N-acetyl glucamine (also know as Meglumine), as a ternary component on the complexation of DRF-4367, a poorly water-soluble and weakly acidic anti-inflammatory molecule, with 2-hydroxypropyl-β-cyclodextrin (HPβCD). The molecular inclusion of DRF-4367 with HPβCD alone and in combination with ternary component was aimed at improvement in solubility and, subsequently, dissolution rate-limited oral bioavailability. The solid complexes of DRF-4367 and HPβCD with or without meglumine (binary and ternary systems, respectively) were prepared as coevaporated product in different stoichiometric ratios and compared against physical mixture. The formation of inclusion complexes was confirmed by using classical instrumental techniques. Phase solubility studies suggested that meglumine was responsible for solubility improvement via multiple factors rather than just providing a favorable pH. Mechanisms and factors governing solubility enhancement were investigated by using phase solubility and thermodynamic parameters. The complexation of DRF-4367 with HPβCD is thermodynamically favored because the Gibbs free energies of transfer of the drug to the cyclodextrin cavity are negative. The solubilization efficiency and stability were further improved while retaining the favorable Gibbs free energies of transfer with the addition of meglumine. Inclusion ternary complex of DRF-4367 with HPβCD and meglumine showed significant improvement in dissolution compared with uncomplexed drug and binary system. Moreover, the phenomena of reprecipitation observed with binary system during dissolution could be avoided with meglumine as an enabling ternary component. This improved physicochemical behavior of ternary complex with the novel inclusion of a polyhydroxy base translated into an enhanced oral bioavailability of DRF-4367 compared with either uncomplexed drug or nanosuspension.     

Use of calcined Mg-Al-hydrotalcite to enhance the stability of celecoxib in the amorphous form.

The use of compound in amorphous forms is a promising approach to improve solubility of poorly water-soluble drugs. However, during storage, amorphous state can spontaneously transform to the lower energy crystalline form and this is a limiting factor for a large commercial use of drugs. In this paper, calcined hydrotalcite was employed to support amorphous celecoxib and several preparations at different weight drug/carrier ratio were prepared. Solubility of celecoxib from the prepared systems was evaluated and its physical stability during storage at different conditions was examined as well. The results show that HTlc-calc can be used as a support of amorphous celecoxib with consequent improvement of drug solubility and physical stability.     

Mechanisms of dissolution of frusemide/PVP solid dispersions

With a discriminating intrinsic dissolution apparatus the dissolution rates and profiles of frusemide-polyvinylpyrrolidone (PVP) mix and solid dispersion systems (10–100% w/w frusemide) have been examined together with scanning electron photomicrographs (SEM) of the dissolution surfaces of compressed discs before and after dissolution. Solid dispersion systems exhibited higher dissolution rates than corresponding mixes and untreated frusemide. The peak intrinsic dissolution rate, found for both mix and dispersion systems containing 40% w/w frusemide, was attributed to a balance of two opposing factors. In mix systems a dissolution-promoting effect of soluble complex formation with PVP is balanced by a viscosity-related retarding effect of increasing PVP content in the diffusion layer. In dispersion systems a large dissolution-promoting effect of the X-ray amorphous state of the drug at the 40% drug level produces a highly supersaturated diffusion layer demonstrated in time/solubility profiles which is also balanced by the increasing PVP content in the diffusion layer. These findings were further supported by the observed dependence of the dissolution rate on the molecular weight and related solution viscosity of the PVP used to form the X-ray amorphous solid dispersion and mechanical mix, in high polymer content systems. In addition, a filming effect over dissolved compact faces shown by SEM, when the drug level was 40% w/w or less was attributed to a PVP layer covering the dissolving face and the change from a crystalline drug-controlled dissolution mechanism to a polymer controlled system.     

The influence of polyvinylpyrrolidone on the dissolution properties of hydroflumethiazide.

The incorporation of hydroflumethiazide with polyvinylpyrrolidone (PVP) was found to retard and to enhance the dissolution of the drug from compressed discs, the magnitude of the effect being dependent on the proportion of PVP present and its method of incorporation. The most active system dissolved sixteen times faster than pure hydroflumethiazide. Low concentrations of PVP were also found to decrease the apparent solubility of hydroflumethiazide while at high concentrations solubility was enhanced. X-ray and infrared analysis of systems suggested the presence of an amorphous form of hydroflumethiazide in coprecipitate systems. The dissolution data were consistent with a physical model which takes account of the roles played by crystalline and amorphous hydroflumethiazide together with the complexing and crystal growth inhibiting effect of PVP on hydroflumethiazide.     

Preparation and in vivo evaluation of immediate-release pellet containing celecoxib solid dispersion

The aim of this study was to make use of small size of immediate-release (IR) pellet and amorphous state of solid dispersion to increase solubility of celecoxib (CLX), a drug in BCS class II. Primary, binary and ternary solid dispersions were developed to choose the final components for solid dispersion. A ternary novel solid dispersion was prepared by incorporation of one aqueous soluble polymer (povidone k17; PVP 17PF), Methacrylate copolymer-based gastric soluble polymer (Eudragit^? EPO) and one pH modulator (MgO). This combination was effective to increase solubility in pH 1.2 up to 25?C30?%. The mechanism of solubility enhancement was proven by DSC, PRXD, and FT-IR. Accordingly, hydrogen bonding or electrostatic interaction of CLX with PVP/Eudragit^? EPO was the main cause to form the amorphous state of CLX within polymer cluster which increasing solubility of drug. Besides, MgO played an important role to change microenviroment for solid dispersion. Pellets containing this solid dispersion were prepared by extrusion and spheronization technique. Effect of four kinds of additive (calcium hydrogen phosphate dihydrate, NaHCO₃, crospovidone, and sodium dodecyl sulfate) on dissolution of CLX from IR pellet was also determined. Because of highest dissolution rate, formulation using sodium dodecyl sulfate was used for pharmacokinetics study. Solid dispersion-IR pellet formulation presented bioequivalence and lower variability in comparison with reference product.     

Effect of Temperature and Moisture on the Physical Stability of Binary and Ternary Amorphous Solid Dispersions of Celecoxib

The effectiveness of different polymers, alone or in combination, in inhibiting the crystallization of celecoxib (CEX) from amorphous solid dispersions (ASDs) exposed to different temperatures and relative humidities was evaluated. It was found that polyvinylpyrrolidone (PVP) and PVP-vinyl acetate formed stronger or more extensive hydrogen bonding with CEX than cellulose-based polymers. This, combined with their better effectiveness in raising the glass transition temperature (T_g) of the dispersions, provided better physical stabilization of amorphous CEX against crystallization in the absence of moisture when compared with dispersions formed with cellulose derivatives. In ternary dispersions containing 2 polymers, the physical stability was minimally impaired by the presence of a cellulose-based polymer when the major polymer present was PVP. On exposure to moisture, stability of the CEX ASDs was strongly affected by both the dispersion hygroscopicity and the strength of the intermolecular interactions. Binary and ternary ASDs containing PVP appeared to undergo partial amorphous–amorphous phase separation when exposed 94% relative humidity, followed by crystallization, whereas other binary ASDs crystallized directly without amorphous–amorphous phase separation.