A year-long extended release nanoformulated cabotegravir prodrug.

Long-acting cabotegravir (CAB) extends antiretroviral drug administration from daily to monthly. However, dosing volumes, injection site reactions and health-care oversight are obstacles towards a broad usage. The creation of poloxamer-coated hydrophobic and lipophilic CAB prodrugs with controlled hydrolysis and tissue penetrance can overcome these obstacles. To such ends, fatty acid ester CAB nanocrystal prodrugs with 14, 18 and 22 added carbon chains were encased in biocompatible surfactants named NMCAB, NM2CAB and NM3CAB and tested for drug release, activation, cytotoxicity, antiretroviral activities, pharmacokinetics and biodistribution. Pharmacokinetics studies, performed in mice and rhesus macaques, with the lead 18-carbon ester chain NM2CAB, showed plasma CAB levels above the protein-adjusted 90% inhibitory concentration for up to a year. NM2CAB, compared with NMCAB and NM3CAB, demonstrated a prolonged drug release, plasma circulation time and tissue drug concentrations after a single 45 mg per kg body weight intramuscular injection. These prodrug modifications could substantially improve CAB's effectiveness.

Analysis and Isolation of Potential Artemisinin Precursors from Waste Streams of Artemisia Annua Extraction.

High-performance liquid chromatography, liquid chromatography-mass spectrometry, and gas chromatography-mass spectrometry methods were developed to analyze the process waste streams of Artemisia Annua extraction. Results from these methods suggested that the final waste from the extraction process could serve as a source of dihydroartemisinic acid (DHAA) that could be converted to additional artemisinin. Two additional impurities were isolated and identified in the waste material as well as in A. annua leaf samples. That these impurities also appear as side-products in chemical transformations of DHAA to artemisinin supports the conclusion that the in vivo transformation proceeds as nonspecific oxidations. These impurities do not appear in isolated artemisinin. A simple, high-yielding procedure for recovery of DHAA from the primary waste stream was developed.

Practical Synthesis of the Bicyclic Darunavir Side Chain: (3R,3aS,6aR)-Hexahydrofuro[2,3-b]furan-3-ol from Monopotassium Isocitrate.

A practical synthesis of (3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-ol-a key intermediate in the synthesis of darunavir-from monopotassium isocitrate is described. The isocitric acid salt, obtained from a high-yielding fermentation fed by sunflower oil, was converted in several steps to a tertiary amide. This amide, along with the compound's ester functionalities, was reduced with lithium aluminum hydride to give, on acidic workup, a transient aminal-triol. This was converted in situ to the title compound, the bicyclic acetal furofuranol side chain of darunavir, a protease inhibitor used in treatment of HIV/AIDS. Key to the success of this process was identifying an optimal amide that allowed for complete reaction and successful product isolation. N-Methyl aniline amide was identified as the most suitable substrate for the reduction and the subsequent cyclization to the desired product. Thus, the side chain is produced in 55% overall yield from monopotassium isocitrate.

Metabolism, excretion, and pharmacokinetics of [14C]INCB018424, a selective Janus tyrosine kinase 1/2 inhibitor, in humans.

The metabolism, excretion, and pharmacokinetics of 3-(4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl)-3-cyclopentylpropanenitrile (INCB018424), a potent, selective inhibitor of Janus tyrosine kinase1/2 and the first investigational drug of its class in phase III studies for the treatment of myelofibrosis, were investigated in healthy human subjects given a single oral 25-mg dose of [(14)C]INCB018424 as an oral solution. INCB018424 and total radioactivity were absorbed rapidly (mean time to reach the maximal drug concentration <1 h), declining in a monophasic or biphasic fashion (mean t(1/2) of 2.32 and 5.81 h, respectively). Recovery of administered radioactivity was fairly rapid (>70% within 24 h postdose) with 74 and 22% recovered in urine and feces, respectively. Parent compound was the predominant entity in the circulation, representing 58 to 74% of the total radioactivity up to 6 h postdose, indicating that the overall circulating metabolite burden was low (<50% of parent). Two metabolite peaks in plasma (M18 and a peak containing M16/M27, both hydroxylations on the cyclopentyl moiety) were identified as major (30 and 14% of parent based on area under the curve from 0 to 24 h). The exposures of other circulating INCB018424-related peaks were <10% of parent, consisting of mono- and dihydroxylated metabolites. The profiles in urine and feces consisted of hydroxyl and oxo metabolites and subsequent glucuronide conjugates with parent drug accounting for <1% of the excreted dose, strongly suggesting that after an oral dose, INCB018424 was >95% absorbed. In healthy subjects administered daily oral doses of unlabeled INCB018424, there were minimal differences in parent and metabolite concentrations between day 1 and day 10, indicating a lack of accumulation of parent or metabolites between single and multiple dosing.

Enantioselective synthesis of Janus kinase inhibitor INCB018424 via an organocatalytic aza-Michael reaction.

An enantioselective synthesis of INCB018424 via organocatalytic asymmetric aza-Michael addition of pyrazoles (16 or 20) to (E)-3-cyclopentylacrylaldehyde (23) using diarylprolinol silyl ether as the catalyst was developed. Michael adducts (R)-24 and (R)-27 were isolated in good yield and high ee and were readily converted to INCB018424.

Enantioselective hydrogenation of 3-alkylidenelactams: high-throughput screening provides a surprising solution.

High-throughput screening of 256 potential catalysts (8 metal precursors x 32 phosphine ligands) has identified [(BDPP)Ir(COD)]BF4 as a catalyst for the enantioselective hydrogenation of 3-alkylidenelactams. This result is surprising given the highly flexible backbone of the BDPP ligand and the ineffectiveness of this catalyst in other applications. The asymmetric hydrogenation appears fairly general for five- and six-membered lactams and in one case has been scaled up to a 20 kg level.