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The absorption and bioavailability of most tyrosine kinase inhibitors are affected by gastrointestinal pH as they are weak basic lipophilic drugs. Hence, concomitant use of acid reducing agents (ARAs) is frequently restricted. Particularly comedication of crystalline dasatinib (Sprycel) and proton‐pump inhibitors (PPIs) should be avoided. Drug–drug interaction (DDI) studies with PPIs report approximately 40%‐80% bioavailability reduction of dasatinib. Limitations in the design of these studies do not allow for assessing the near maximum DDI as timing of PPI dosing was either not reported or 22 h prior to dasatinib intake. We conducted a DDI study of crystalline dasatinib and omeprazole in healthy, fasted participants, investigating the impact of PPI comedication on dasatinib plasma exposure at a time point when the near maximum DDI effect is expected. Participants were administered omeprazole (day 2‐5) to reach steady state. On day 6, a single dose of crystalline dasatinib was given. Crystalline dasatinib dosing alone on day 1 served as control (single dose). The dosing interval between omeprazole administration and crystalline dasatinib was 10 h (median [range: 9‐10 h]). Dasatinib Cmax and AUC0‐24 were reduced by 96% and 89% by omeprazole comedication. Cmax was 224.6 ± 104.7 ng/mL (mean ± SD) and 8.0 ± 4.5 ng/mL (P < .0001) and AUC0‐24 was 797.6 ± 274.5 and 90.6 ± 38.1 h·ng/mL (P < .0001) without and with omeprazole. T1/2 was 5.7 ± 1.5 h (mean ± SD) with crystalline dasatinib dosing alone and could not be reliably calculated with comedication. To ensure optimal patient outcome, it is vital to investigate bioavailability of pH‐sensitive drugs at the maximal DDI effect of ARAs to understand the worst‐case influence for efficient clinical management. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Research has been conducted on N-boc-protected delta-amino alpha,beta-unsaturated gamma-keto ester. The diastereoselective reduction of this compound to the corresponding alcohols carried out via the use of boron- and aluminum-based reducing reagents is described.

A study was undertaken to analyze the influence of tricarbonylchromium complexation on alkylation of benzylic anions. Method utilized involved the preparation of tricarbonylchromium complexes of racemic and resolved 3-(dipropylamino)chromans. Benzylic alkylation of the complexes gave way to 4-alkylated derivatives while alkylations of the endo complex provided only the expected trans products. Results indicated that steric effects plus nature of the electrophiles influence the outcome of alkylations.

A series of acyclic C2-symmetric HIV-1 protease inhibitors were synthesized using D-mannitol as template. The inhibitory properties of the compounds obtained were then determined with purified HIV-1 protease in a standardized assay. 2,5-Bis{N-(tert-butoxycarbonyl)amino}-2,5-dideoxy-1,6-di-O-phenyl-L-iditol showed inhibitory activity which was several times less compared to a related compound. Altering its P1/P1' substituent did not enhance its antiviral activity.

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°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°C and that b) conversion of 1?2 only occurs after crystallization from supersaturated aqueous solutions at a water activity =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°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. [ABSTRACT FROM AUTHOR]

The readily available N-Boc-protected δ-amino α,β-unsaturated γ,-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 LiA1H(O-t-Bu)[sub 3] in EtOH at -78 °C under chelation control, and 5:95 (98% yield), using NB-Enantride in THF at -78 °C under Felkin-Anh control. [ABSTRACT FROM AUTHOR]

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.