Enhanced Bioavailability and Reduced Variability of Dasatinib and Sorafenib with a Novel Amorphous Solid Dispersion Technology Platform.

Despite clinical advances with protein kinase inhibitors (PKIs), oral administration of many PKIs is associated with highly variable plasma exposure and a narrow therapeutic window. We developed a novel hybrid nanoparticle-amorphous solid dispersion (ASD) technology platform consisting of an amorphous PKI embedded in a polymer matrix. The technology was used to manufacture immediate-release formulations of 2 tyrosine kinase inhibitors (TKIs), dasatinib and sorafenib. Our primary objective was to improve the absorption properties and reduce the pharmacokinetic (PK) variability of each TKI. The PKs of XS004 (dasatinib-ASD, 100 mg tablet) and XS005 (sorafenib-ASD, 2 × 50 mg capsules) were compared with their crystalline formulated reference drugs (140 mg of dasatinib-reference and 200 mg of sorafenib-reference). The in vitro biopharmaceutics of dasatinib-ASD and XS005-granulate showed sustained increased solubility in the pH range 1.2-8.0 compared to their crystalline references. In vivo, XS004 was bioequivalent at a 30% lower dose and showed increased absorption and bioavailability, with 2.1-4.8 times lower intra- and intersubject variability compared to the reference. XS005 had an increased absorption and bioavailability of 45% and 2.2-2.8 times lower variability, respectively, but it was not bioequivalent at the investigated dose level. Taken together, the formulation platform is suited to generate improved PKI formulations with consistent bioavailability and a reduced pH-dependent absorption process.

Despite warnings, co-medication with proton pump inhibitors and dasatinib is common in chronic myeloid leukemia, but XS004, a novel oral dasatinib formulation, provides reduced pH-dependence, minimizing undesirable drug-drug interactions.

BACKGROUND: Dasatinib and other tyrosine kinase inhibitors (TKI) have revolutionized the treatment of chronic myeloid leukemia (CML). However, as a lipophilic weak base, crystalline monohydrate, dasatinib (Sprycel®) is poorly soluble, rendering a pH-dependent absorption and a highly variable bioavailability. Thus, co-medication with proton pump inhibitors (PPI) profoundly impairs dasatinib uptake and is clearly recommended against. XS004 is a novel oral immediate release and amorphous solid dispersion (ASD) formulation of dasatinib and is bioequivalent to the original crystalline dasatinib at 30% lower dosages. XS004 is designed to mitigate gastric pH dependency, thus optimizing absorption and bioavailability. METHODS: We investigated the prevalence of dasatinib and PPI co-medication among chronic-phase CML patients in a real-world setting and assessed the plasma pharmacokinetics (PK) of XS004 with and without PPI co-medication (omeprazole) in healthy volunteers. RESULTS: Using the Swedish CML and Prescribed Drug Registers, we identified 676 TKI-treated CML patients; 320 (47%) had been prescribed PPI at some point after CML diagnosis. Among dasatinib-treated patients, the 2-year cumulative PPI co-medication was 24%. Interestingly, the 5-year overall survival was significantly lower for TKI-treated CML patients with versus without PPI co-medication (79% vs. 94%; hazard ratio 3.5; 95% confidence interval, 2.1-5.3; p < .0001). When assessing PK of XS004, neither Cmax nor area under the plasma concentration curve levels in plasma were significantly altered by the PPI co-medication. CONCLUSION: In conclusion, despite warnings, PPI co-medication is common among dasatinib-treated CML patients in a real-world setting. The new XS004 ASD formulation of dasatinib provided, in contrast to original crystalline dasatinib, superior pH independence with stable bioavailability, thereby minimizing drug-drug interactions. This may improve the long-term efficacy and tolerability of dasatinib in CML.

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.

Carbon dioxide-mediated generation of hybrid nanoparticles for improved bioavailability of protein kinase inhibitors.

PURPOSE: A versatile methodology is demonstrated for improving dissolution kinetics, gastrointestinal (GI) absorption, and bioavailability of protein kinase inhibitors (PKIs). METHODS: The approach is based on nanoparticle precipitation by sub- or supercritical CO2 together with a matrix-forming polymer, incorporating surfactants either during or after nanoparticle formation. Notably, striking synergistic effects between hybrid PKI/polymer nanoparticles and surfactant added after particle formation is investigated. RESULTS: The hybrid nanoparticles, consisting of amorphous PKI embedded in a polymer matrix (also after 12 months), display dramatically increased release rate of nilotinib in both simulated gastric fluid and simulated intestinal fluid, particularly when surfactants are present on the hybrid nanoparticle surface. Similar results indicated flexibility of the approach regarding polymer identity, drug load, and choice of surfactant. The translation of the increased dissolution rate found in vitro into improved GI absorption and bioavalilability in vivo was demonstrated for male beagle dogs, where a 730% increase in the AUC0-24h was observed compared to the benchmark formulation. Finally, the generality of the formulation approach taken was demonstrated for a range of PKIs. CONCLUSIONS: Hybrid nanoparticles combined with surfactant represent a promising approach for improving PKI dissolution rate, providing increased GI absorption and bioavailability following oral administration.

Physical characterization of anhydrous and hydrous forms of the hydrochloride salt of BVT.5182 a novel 5-HT(6) receptor antagonist.

The physicochemical properties of 1-benzenesulfonyl-4-(piperazin-1-yl)-indole hydrochloride, a novel 5-HT(6) receptor antagonist for the treatment of obesity were characterized. Two solid state forms were identified at ambient conditions (23 degrees C): an anhydrate form (1) and a hydrate form (2), with 1.5 moles of H(2)O. The latter easily dehydrates and rehydrates without affecting the crystal morphology. Investigations of the propensity for interconversion between the two forms reveal that a) conversion of 2-->1 takes place above 145 degrees C and that b) conversion of 1-->2 only occurs after crystallization from supersaturated aqueous solutions at a water activity >or=0.94 or in the presence of comparable amounts of crystals of 2 in water at ambient conditions. However, in an equimolar suspension of 1 and 2 at 37 degrees C no phase transformation was observed. Thus, the difference in chemical potential between the two forms is small. Form 1 was shown to have overall favorable solid state properties and, hence, considered the preferred form for continued pharmaceutical development. The characterization was performed by means of light microscopy, scanning electron microscopy, powder X-ray diffraction, FTIR/NIR-spectroscopy, differential scanning calorimetry, hot stage microscopy, thermogravimetry, dynamic vapor sorption, Karl Fischer water content determination, phase stability studies of suspensions, solubility, and intrinsic dissolution rate measurements.

Diastereoselective reduction of a chiral N-Boc-protected delta-amino-alpha,beta-unsaturated gamma-keto ester Phe-Gly dipeptidomimetic.

The readily available N-Boc-protected delta-amino alpha,beta-unsaturated gamma-keto ester 1 was diastereoselectively reduced to the corresponding alcohols 2 and 3, using boron- and aluminum-based reducing reagents. Reduction reactions were successful and resulted in anti/syn ratios of alcohols of >95:5 (80% yield), using LiAlH(O-t-Bu)(3) in EtOH at -78 degrees C under chelation control, and 5:95 (98% yield), using NB-Enantride in THF at -78 degrees C under Felkin-Anh control.