A Solid-State Approach to Enable Early Development Compounds: Selection and Animsal Bioavailability Studies of an Itraconazole Amorphous Solid Dispersion

Evaluate the ability of PVP to inhibit crystallization of amorphous solid dispersions by density functional theory and experimental verify

In this study, we used density functional theory (DFT) to predict polymer-drug interactions, and then evaluated the ability of poly (vinyl pyrrolidone) (PVP) to inhibit crystallization of amorphous solid dispersions by experimental-verification. Solid dispersions of PVP/resveratrol (Res) and PVP/griseofulvin (Gri) were adopted for evaluating the ability of PVP to inhibit crystallization. The density functional theory (DFT) with the B3LYP was used to calculate polymer-drug and drug-drug interactions. Fourier transform infrared spectroscopy (FTIR) was used to confirm hydrogen bonding interactions. Polymer-drug miscibility and drug crystallinity were characterized by the modulated differential scanning calorimetry (MDSC) and X-ray powder diffraction (XRD). The release profiles were studied to investigate the dissolution advantage. DFT results indicated that E_PVP-Res>E_Res-Res (E: represents hydrogen bonding energy). A strong interaction was formed between PVP and Res. In addition, Fourier transform infrared spectroscopy (FTIR) analysis showed hydrogen bonding formed between PVP and Res, but not between PVP and Gri. MDSC and XRD results suggested that 70-90wt% PVP/Res and PVP/Gri solid dispersions formed amorphous solid dispersions (ASDs). Under the accelerated testing condition, PVP/Res dispersions with higher miscibility quantified as 90/10wt% were more stable than PVP/Gri dispersions. The cumulative dissolution rate of 90wt% PVP/Res dispersions still kept high after 90days storage due to the strong interaction. However, the cumulative dissolution rate of PVP/Gri solid dispersions significantly dropped because of the recrystallization of Gri.

Effects of long term treatment with high doses of odanacatib on bone mass, bone strength, and remodeling/modeling in newly ovariectomized monkeys

The objectives here were to evaluate the effects of odanacatib (ODN) at doses exceeding the clinical exposure on biomechanical properties of lumbar vertebrae (LV), hip and central femur (CF), and compare ODN to alendronate (ALN) on bone remodeling/modeling in ovariectomized (OVX) monkeys. Ten days post-surgery, animals were treated with vehicle (VEH), ODN-L (2mg/kg/day, p.o.), ODN-H (8/4mg/kg/day), or ALN (30μg/kg/week, s.c.) for 20months. An intact group was also included. ODN-L provided systemic exposures of 1.8-fold of clinical exposure. ODN-H started at 20-fold for 5.5months, and then reduced to 7.8-fold of clinical exposure, compared to ALN at approximated clinical exposure. From cross sectional analyses, LV density and peak load in ODN at both doses or ALN were not different from VEH or Intact. However, cortical thickness of femoral neck (FN) and CF in ODN were higher (21-34%, p<0.05) than VEH, due to smaller endocortical (Ec) perimeter of FN (10-11%; p<0.05) and CF (9-12%; ODN-L, p<0.05), and larger CF periosteal (Ps) perimeter (2-12%; ODN-H, p<0.001) versus VEH. ODN groups also showed slightly higher cortical porosity and Ps non-lamellar bone in CF. ODN-H treatment resulted in higher CF peak load (p<0.05) versus VEH. For all bone sites analyzed, a positive, linear relationship (r(2)=0.46-0.69, p<0.0001) of peak load to density or structural parameters was demonstrated. No treatment-related differences in the derived intrinsic strength properties were evidenced as compared between groups. ALN reduced all remodeling surfaces without affecting Ps modeling. Trabecular and intracortical remodeling were reduced in ODN groups, similar to ALN. Ec mineralizing surface in ODN-H trended to be lower than VEH by month 20, but Ec bone formation indices in ODN groups generally were not different from VEH. Ps modeling in ODN groups was significantly higher than other treatment groups. This study overall demonstrated the bone safety profile of ODN and its unique mechanism on cortical bone supporting the clinical application for osteoporosis treatment.

Spray drying formulation of amorphous solid dispersions

Spray drying is a well-established manufacturing technique which can be used to formulate amorphous solid dispersions (ASDs) which is an effective strategy to deliver poorly water soluble drugs (PWSDs). However, the inherently complex nature of the spray drying process coupled with specific characteristics of ASDs makes it an interesting area to explore. Numerous diverse factors interact in an inter-dependent manner to determine the final product properties. This review discusses the basic background of ASDs, various formulation and process variables influencing the critical quality attributes (CQAs) of the ASDs and aspects of downstream processing. Also various aspects of spray drying such as instrumentation, thermodynamics, drying kinetics, particle formation process and scale-up challenges are included. Recent advances in the spray-based drying techniques are mentioned along with some future avenues where major research thrust is needed.

Amorphous solid dispersions: Rational selection of a manufacturing process

Amorphous products and particularly amorphous solid dispersions are currently one of the most exciting areas in the pharmaceutical field. This approach presents huge potential and advantageous features concerning the overall improvement of drug bioavailability. Currently, different manufacturing processes are being developed to produce amorphous solid dispersions with suitable robustness and reproducibility, ranging from solvent evaporation to melting processes. In the present paper, laboratorial and industrial scale processes were reviewed, and guidelines for a rationale selection of manufacturing processes were proposed. This would ensure an adequate development (laboratorial scale) and production according to the good manufacturing practices (GMP) (industrial scale) of amorphous solid dispersions, with further implications on the process validations and drug development pipeline.

Hot melt extruded Aprepitant-Soluplus solid dispersion: preformulation considerations, stability and in vitro study

CONTEXT

Solubility limitation of BCS class II drugs pose challenges to in vitro release.

OBJECTIVE

To investigate the miscibility of Aprepitant (APR) and Soluplus(®) (SOL) for hot melt extrusion (HME) viability and improved in vitro release of APR.

METHODS

Solubility parameters of APR and SOL from group contribution methods were evaluated. Heat-cool-heat differential scanning calorimetry (DSC) scans were assessed for determining the glass forming ability (GFA) and glass stability (GS) of APR. An optimum HME temperature was selected based on melting point depression in physical mixtures. Moisture sorption isotherms were collected using a dynamic vapor sorption (DVS) analyzer at 25 °C. A 1:4 APR:SOL physical mixture was extruded in a co-rotating 12 mm twin screw extruder and in vitro release was assessed in fasted state simulated intestinal fluid (FaSSIF) with 0.25% SLS. Extrudates were analyzed using TGA, DSC, XRD and FTIR.

RESULTS

APR was classified as a class II glass former. APR and SOL had composition dependent miscibility based on Gibb's free energy of mixing. Extrudate prepared using HME had an amorphous as well as a crystalline phase that showed good stability in accelerated stability conditions. Smaller particle size extrudates exhibited a higher % moisture uptake and in vitro release compared to larger particle size extrudates. Enhanced in vitro release of APR from extrudates was attributed to amorphization of APR, solubilization as well as crystal growth inhibition effect of SOL due to H-bond formation with APR.

CONCLUSIONS

A solid dispersion of APR with improved in vitro release was successfully developed using HME technology.

Charge-assisted intermolecular hydrogen bond formed in coamorphous system is important to relieve the pH-dependent solubility behavior of lurasidone hydrochloride

In comparison to amorphous LH, coamorphous LH-REP without evidence of intermolecular hydrogen bond, exhibited greatly improved solubility with pH-dependent behavior, significantly enhanced dissolution rate and physical stability.

Multivariate Quantification of the Solid State Phase Composition of Co-Amorphous Naproxen-Indomethacin

To benefit from the optimized dissolution properties of active pharmaceutical ingredients in their amorphous forms, co-amorphisation as a viable tool to stabilize these amorphous phases is of both academic and industrial interest. Reports dealing with the physical stability and recrystallization behavior of co-amorphous systems are however limited to qualitative evaluations based on the corresponding X-ray powder diffractograms. Therefore, the objective of the study was to develop a quantification model based on X-ray powder diffractometry (XRPD), followed by a multivariate partial least squares regression approach that enables the simultaneous determination of up to four solid state fractions: crystalline naproxen, γ-indomethacin, α-indomethacin as well as co-amorphous naproxen-indomethacin. For this purpose, a calibration set that covers the whole range of possible combinations of the four components was prepared and analyzed by XRPD. In order to test the model performances, leave-one-out cross validation was performed and revealed root mean square errors of validation between 3.11% and 3.45% for the crystalline molar fractions and 5.57% for the co-amorphous molar fraction. In summary, even four solid state phases, involving one co-amorphous phase, can be quantified with this XRPD data-based approach.

Effect of hydrophilic additives on the dissolution and pharmacokinetic properties of itraconazole-enteric polymer hot-melt extruded amorphous solid dispersions

Hot-melt extrusion technology has been widely reported for producing amorphous solid dispersions of poorly water-soluble compounds. A number of studies revealed that enteric polymers containing ionizable groups are able to improve the physical stability and maintain drug supersaturation, thereby enhancing oral bioavailability. However, our previous studies found that itraconazole (ITZ)-enteric polymer amorphous solid dispersions are hydrophobic and poorly wettable. Moreover, drug release in an acidic environment (i.e. stomach) is very limited, indicating a narrow absorption window. In the present study, we investigated the effect of hydrophilic additives on the in vitro and in vivo performance of ITZ-enteric polymer amorphous solid dispersions. Incorporating Vitamin E TPGS into ITZ-HPMCAS amorphous solid dispersions significantly improved drug release in the acidic media. Surprisingly, a low concentration of Vitamin E TPGS also enhanced the degree of drug supersaturation in neutral pH media, which is unique as compared with other tested hydrophilic additives. This effect is not due to the solubilization of the surfactant. We further formulated the amorphous solid dispersions into tablet dosage forms and evaluated their performance in a bio-relevant dissolution media. Our optimized formulations exhibited drastically enhanced dissolution profiles as compared with the commercial ITZ product and ITZ amorphous solid dispersion without hydrophilic additive. In vivo study showed that Vitamin E TPGS induced rapid drug absorption after oral administration. Moreover, the elimination half-life of ITZ was prolonged due to the enzyme inhibition effect of Vitamin E TPGS.

Matrix effects in nilotinib formulations with pH-responsive polymer produced by carbon dioxide-mediated precipitation

Factors determining the pH-controlled dissolution kinetics of nilotinib formulations with the pH-titrable polymer hydroxypropyl methylcellulose phthalate, obtained by carbon dioxide-mediated precipitation, were mechanistically examined in acid and neutral environment. The matrix effect, modulating the drug dissolution, was characterized with a battery of physicochemical methodologies, including ToF-SIMS for surface composition, SAXS/WAXS and modulated DSC for crystallization characterization, and simultaneous UV-imaging and Raman spectroscopy for monitoring the dissolution process in detail. The hybrid particle formulations investigated consisted of amorphous nilotinib embedded in a polymer matrix in single continuous phase, displaying extended retained amorphicity also under wet conditions. It was demonstrated by Raman and FTIR spectroscopy that the efficient drug dispersion and amorphization in the polymer matrix were mediated by hydrogen bonding between the drug and the phthalate groups on the polymer. Simultaneous Raman and UV-imaging studies of the effect of drug load on the swelling and dissolution of the polymer matrix revealed that high nilotinib load prevented matrix swelling on passage from acid to neutral pH, thereby preventing re-precipitation and re-crystallization of incorporated nilotinib. These findings provide a mechanistic foundation of formulation development of nilotinib and other protein kinase inhibitors, which are now witnessing an intense therapeutic and industrial attention due to the difficulty in formulating these compounds so that efficient oral bioavailability is reached.

An Insight into Different Stabilization Mechanisms of Phenytoin Derivatives Supersaturation by HPMC and PVP

In this study, we examined the stabilization mechanism of drug supersaturation by hypromellose (HPMC) and polyvinylpirrolidone (PVP). The poorly water-soluble drugs, phenytoin (diphenylhydantoin, DPH), and its synthesized derivatives monomethylphenytoin (MDPH) and dimethylphenytoin (DMDPH) were used. DPH supersaturation was efficiently maintained by both HPMC and PVP. HPMC maintained the supersaturation of MDPH and DMDPH in a similar manner to that of DPH, whereas the ability of PVP to maintain drug supersaturation increased as follows: DPH > MDPH > DMDPH. Caco-2 permeation studies and nuclear magnetic resonance measurements revealed that the permeability and molecular state of the drug in a HPMC solution barely changed. In fact, the solubilization of the drug into PVP changed its apparent permeability and molecular state. The drug solubilization efficiency by PVP was higher and followed the order: DPH > MDPH > DMDPH. The different drug solubilization efficiencies most likely result from the different strengths in the intermolecular interaction between the DPH derivatives and PVP. The difference in the stabilization mechanism of drug supersaturation by HPMC and PVP could determine whether the efficient maintenance of the drug supersaturation was dependent on the drug species.

Improvement of dissolution rate of indomethacin by inkjet printing

The aim of this study was to prepare printable inks of the poorly water soluble drug indomethacin (IMC), fabricate printed systems with flexible doses and investigate the effect of ink excipients on the printability, dissolution rate and the solid state properties of the drug. A piezoelectric inkjet printer was used to print 1×1cm(2) squares onto a paper substrate and an impermeable transparency film. l-arginine (ARG) and polyvinylpyrrolidone (PVP) were used as additional formulation excipients. Accurately dosed samples were generated as a result of the ink and droplet formation optimization. Increased dissolution rate was obtained for all formulations. The formulation with IMC and ARG printed on transparency film resulted in a co-amorphous system. The solid state characteristics of the printed drug on porous paper substrates were not possible to determine due to strong interference from the spectra of the carrier substrate. Yet, the samples retained their yellow color after 6months of storage at room temperature and after drying at elevated temperature in a vacuum oven. This suggests that the samples remained either in a dissolved or an amorphous form. Based on the results from this study a formulation guidance for inkjet printing of poorly soluble drugs is also proposed.

CapsMorph® technology for oral delivery--theory, preparation and characterization

The CapsMorph(®) technology prepares amorphous drugs for oral delivery by encapsulating them into porous materials. Hesperidin as model compound was loaded onto AEROPERL(®) 300 Pharma using the wetness impregnation method. Hesperidin was dissolved in dimethyl sulfoxide (DMSO) and alternatively in DMSO with addition of Tween 80. The drug solutions were added dropwise to the porous material and subsequently DMSO was evaporated. The AEROPERL(®) 300 Pharma could be loaded with about 30% hesperidin in the amorphous form. Amorphous state was verified by X-ray diffraction and differential scanning calorimetry. The CapsMorph(®) formulation was compared regarding properties determining oral bioavailability, i.e., kinetic saturation solubility and dissolution rate to raw drug powder and hesperidin nanocrystals. The saturation solubility of CapsMorph(®) without Tween 80 was 654 μg/ml, which is 36-fold higher than the raw drug powder (18 μg/ml) and about 20 times higher than nanocrystals (30 μg/ml). In vitro release was faster (100% in 10 min at pH 6.8) compared to dissolution of nanocrystals with about 15%. Addition of Tween 80 to CapsMorph(®) lowered the solubility (168 μg/ml) and slowed down the release, but provided longer times of supersaturation without precipitation of drug. Based on these data, it appears that drug loaded porous materials provide better formulations compared to nanocrystals for poorly soluble drugs.

NIPTE: a multi-university partnership supporting academic drug development

The strategic goal of academic translational research is to accelerate translational science through the improvement and development of resources for moving discoveries across translational barriers through 'first in humans' studies. To achieve this goal, access to drug discovery resources and preclinical IND-enabling infrastructure is crucial. One potential approach of research institutions for coordinating preclinical development, based on a model from the National Institute for Pharmaceutical Technology and Education (NIPTE), can provide academic translational and medical centers with access to a wide variety of enabling infrastructure for developing small molecule clinical candidates in an efficient, cost-effective manner.

Comparison of cefpodoxime proxetil release and antimicrobial activity from tablet formulations: complexation with hydroxypropyl-β-cyclodextrin in the presence of water soluble polymer

This study aims to prove the complexation of cefpodoxime proxetil (CP) by hydroxypropyl-β-cyclodextrin (HP-β-CD) in the presence of sodium carboxymethyl cellulose (Na CMC), and makes a comparison of commercial tablets by dissolution and antimicrobial activity studies. The CP--HP-β-CD complex was prepared by kneading method and characterized by SEM, FTIR and DSC. The solubility method was used to investigate the effect of HP-β-CD and Na CMC on the solubility of CP. The complex tablets were prepared using direct compression method. Dissolution studies were performed with complex tablets and commercial tablets in pH 1.2, 4.5, 6.8 and 7.4 buffer solutions. It was observed that complexation occurred in all formulations, and HP-β-CD is able to increase CP solubility and dissolution rate of CP was improved from complex tablets, when compared with commercial tablets. Furthermore, the antimicrobial activity studies revealed that the CP--HP-β-CD complex and complex tablets were shown to have more effective antimicrobial activity than commercial tablets. It is evident from the results that complexation with HP-β-CD in the presence of Na CMC is feasible way to prepare a more efficient tablet formulation with improved dissolution and antimicrobial activity.

Dissolution enhancement of quercetin through nanofabrication, complexation, and solid dispersion

The main aim of this study was to enhance the dissolution rate of a poorly water-soluble antioxidant drug, quercetin, by fabricating its nanoparticles, complexes and solid dispersions using evaporative precipitation of nanosuspension (EPN). We studied the influence of the type of antisolvent, drug concentration and solvent to antisolvent ratio on the quercetin particles formed during EPN. With water as antisolvent, the particles were big, irregular and flake type but with benzene or hexane as antisolvent, the particles were smaller and needle type. Smallest particles of 220 nm diameter were achieved with hexane as antisolvent, lowest drug concentration and highest solvent to antisolvent ratio. The relative dissolution values showed that the dissolution rate of the EPN prepared quercetin nanoparticles was much higher than that of the raw drug. Quercetin formed inclusion complexes with β-cyclodextrin, and solid dispersions with polyvinylpyrrolidone and pluronic F127, where quercetin was present in an amorphous form and/or was dispersed at a molecular level. The dissolution rate of quercetin in its complexes and solid dispersions improved significantly from the raw quercetin as indicated by the percent dissolution efficiency. It was interesting to note that at lower carrier concentration, the solid dispersions of quercetin with polyvinylpyrrolidone and pluronic F127 presented better dissolution than its complex with β-cyclodextrin but at higher carrier concentration, there was no significant difference in the dissolution behavior of the three formulations. Using Korsmeyer-Peppas model, diffusion was found to be the main release mechanism.