Development of 3D DLP Printed Sustained Release Ibuprofen Tablets and Their Pharmacokinetic Evaluation in Rats.

The objective of the present study was to develop digital light processing (DLP) 3D printed sustained release ibuprofen (IBU) tablets using 3D DLP printers for evaluation in in vitro release and in vivo pharmacokinetic studies with their in vitro-in vivo correlation. The resin formulation and printing parameters were optimized using quality by design (QbD) approach, and IBU tablets were printed using DLP printers which works at 385 and 405 nm wavelengths. Our results demonstrated that formulation consisting of polyethylene glycol diacrylate (PEGDA) 700, water, IBU, and riboflavin printed at 40-s bottom layer exposure time and 30-s exposure time produced tablets using both 385 and 405 nm wavelengths. In vitro dissolution studies showed > 70% drug release at the end of 24 h when printed at 405 nm wavelength with no significant difference between tablets printed at 385 nm. In vivo pharmacokinetic evaluation of the optimized 3D printed tablets printed at 405 nm at oral dose of 30 mg/kg in rats showed sustained release of IBU with significantly (p < 0.05) higher Cmax of 30.12 ± 2.45 µg/mL and AUC(0-24 h) of 318.97 ± 16.98 (µg/mL × h) compared to marketed IBU tablet (control). In vivo-in vitro correlation studies showed 80% of drug was absorbed in vivo within 3 h from the pulverized 3D printed tablet, whereas intact 3D tablet showed sustained release of IBU with > 75% IBU release in 24 h in vitro. Overall, IBU tablets fabricated using DLP printing demonstrated sustained release and enhanced systemic absorption with no significant difference in their release profile at different wavelengths.

Cost-Effectiveness Model Shows Superiority of Wireless Spinal Cord Stimulation Implantation Without a Separate Trial.

OBJECTIVE: We evaluated the cost-effectiveness of wireless spinal cord stimulation (Wireless SCS) with single stage "direct to permanent" implantation vs. screening with temporary electrodes and an external pulse generator followed by implantation of a system for long-term use (IPG SCS). MATERIALS AND METHODS: We created a cost model that takes a 2019 United States (U.S.) payer perspective and is based on IPG SCS cost models for subjects with chronic back and/or leg pain. Our six-month decision tree includes the screening trial period (success ≥50% relief) and leads to various levels of pain relief with or without complications for IPG SCS and Wireless SCS and without complications for conventional medical management (CMM). Every three months in the follow-on 15-year Markov model (with costs and quality-adjusted life years discounted 3.5% annually), subjects remain stable or transition to deteriorated health or death. Subjects who fail SCS receive CMM. After 60 Markov cycles, a 100,000-sample simulation reveals the impact of maximum willingness-to-pay (WTP) from $10,000 to $100,000 per quality-adjusted life year on net monetary benefit (NMB). Sensitivity analyses considered the impact of the Wireless SCS screening success rate, Wireless SCS device cost, and IPG SCS device longevity. RESULTS: Compared with IPG SCS, Wireless SCS offers higher clinical effectiveness at a lower cost and a higher NMB for our WTP thresholds and is, thus, dominant. Wireless SCS is also cost-effective compared with CMM. Results remain robust with 1) Wireless SCS screening success rates as low as 85% (dominant), 2) the cost of the Wireless SCS devices as high as $55,000 (cost-effective), and 3) IPG SCS devices lasting 12 years (dominant). CONCLUSIONS: In this model, compared with IPG SCS or with CMM, Wireless SCS is a superior strategy.

Genome-wide analysis of clopidogrel active metabolite levels identifies novel variants that influence antiplatelet response.

Clopidogrel is one of the most commonly used therapeutics for the secondary prevention of cardiovascular events in patients with acute coronary syndromes. However, considerable interindividual variation in clopidogrel response has been documented, resulting in suboptimal therapy and an increased risk of recurrent events for some patients. In this investigation, we carried out the first genome-wide association study of circulating clopidogrel active metabolite levels in 513 healthy participants to directly measure clopidogrel pharmacokinetics. We observed that the CYP2C19 locus was the strongest genetic determinant of active metabolite formation (P=9.5×10). In addition, we identified novel genome-wide significant variants on chromosomes 3p25 (rs187941554, P=3.3×10) and 17q11 (rs80343429, P=1.3×10), as well as six additional loci that showed suggestive evidence of association (P≤1.0×10). Four of these loci showed nominal associations with on-clopidogrel ADP-stimulated platelet aggregation (P≤0.05). Evaluation of clopidogrel active metabolite concentration may help identify novel genetic determinants of clopidogrel response, which has implications for the development of novel therapeutics and improved antiplatelet treatment for at-risk patients in the future.

Phase 1 trial of IL-15 trans presentation blockade using humanized Mikß1 mAb in patients with T-cell large granular lymphocytic leukemia.

In the present study, Hu-Mikß1, a humanized mAb directed at the shared IL-2/IL-15Rß subunit (CD122) was evaluated in patients with T-cell large granular lymphocytic (T-LGL) leukemia. Hu-Mikß1 blocked the trans presentation of IL-15 to T cells expressing IL-2/IL-15Rß and the common γ-chain (CD132), but did not block IL-15 action in cells that expressed the heterotrimeric IL-15 receptor in cis. There was no significant toxicity associated with Hu-Mikß1 administration in patients with T-LGL leukemia, but no major clinical responses were observed. One patient who had previously received murine Mikß1 developed a measurable Ab response to the infused Ab. Nevertheless, the safety profile of this first in-human study of the humanized mAb to IL-2/IL-15Rß (CD122) supports its evaluation in disorders such as refractory celiac disease, in which IL-15 and its receptor have been proposed to play a critical role in the pathogenesis and maintenance of disease activity.

3D DLP-printed cannabinoid microneedles patch and its pharmacokinetic evaluation in rats.

OBJECTIVE: The objective of the present study was to enhance the bioavailability of cannabidiol (CBD) using 3D Digital Light Processing (DLP)-printed microneedle (MN) transdermal drug delivery system. METHODS: CBD MN patch was fabricated and optimized using 3D DLP printing using CBD (8% w/v), Lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) (0.49% w/v), distilled water (20% w/v), and poly (ethylene glycol) dimethacrylate 550 (PEGDAMA 550) (up to 100% w/v). CBD MNs were characterized for their morphology, mechanical strength, in vitro release study, ex vivo permeation study, and in vivo pharmacokinetic (PK) profile. KEY FINDINGS: Microscopic images showed that sharp CBD MNs with a height of ~800 µm, base diameter of ~250 µm, and tip with a radius of curvature (RoC) of ~15 µm were successfully printed using optimized printing parameters. Mechanical strength studies showed no significant deformation in the morphology of CBD MNs even after applying 0.5N/needle force. Ex vivo permeation study showed significant (P < .0001) permeation of CBD in the receiving media as compared to CBD patch (control). In vivo PK study showed significantly (P < .05) enhanced bioavailability in the case of CBD MN patch as compared to CBD subcutaneous inj. (control). CONCLUSION: Overall, systemic absorption of CBD was significantly enhanced using 3D-printed MN drug delivery system.

The functional G143E variant of carboxylesterase 1 is associated with increased clopidogrel active metabolite levels and greater clopidogrel response.

INTRODUCTION: Carboxylesterase 1 (CES1) is the primary enzyme responsible for converting clopidogrel into biologically inactive carboxylic acid metabolites. METHODS: We genotyped a functional variant in CES1, G143E, in participants of the Pharmacogenomics of Anti-Platelet Intervention (PAPI) study (n=566) and in 350 patients with coronary heart disease treated with clopidogrel, and carried out an association analysis of bioactive metabolite levels, on-clopidogrel ADP-stimulated platelet aggregation, and cardiovascular outcomes. RESULTS: The levels of clopidogrel active metabolite were significantly greater in CES1 143E-allele carriers (P=0.001). Consistent with these findings, individuals who carried the CES1 143E-allele showed a better clopidogrel response as measured by ADP-stimulated platelet aggregation in both participants of the PAPI study (P=0.003) and clopidogrel-treated coronary heart disease patients (P=0.03). No association was found between this single nucleotide polymorphism and baseline measures of platelet aggregation in either cohort. CONCLUSION: Taken together, these findings suggest, for the first time, that genetic variation in CES1 may be an important determinant of the efficacy of clopidogrel.

A phase 1 study of TRC102, an inhibitor of base excision repair, and pemetrexed in patients with advanced solid tumors.

INTRODUCTION: TRC102 potentiates the activity of cancer therapies that induce base excision repair (BER) including antimetabolite and alkylating agents. TRC102 rapidly and covalently binds to apurinic/apyrimidinic (AP) sites generated during BER, and TRC102-bound DNA causes topoisomerase II-dependent irreversible strand breaks and apoptosis. This study assessed the safety, maximum-tolerated dose (MTD), pharmacokinetics and pharmacodynamics of TRC102 alone and in combination with pemetrexed. PURPOSE: Patients with advanced solid tumors received oral TRC102 daily for 4 days. Two weeks later, patients began standard-dose pemetrexed on day 1 in combination with oral TRC102 on days 1 to 4. The pemetrexed-TRC102 combination was repeated every 3 weeks until disease progression. METHODS: Twenty-eight patients were treated with TRC102 at 15, 30, 60 or 100 mg/m(2)/d. The MTD was exceeded at 100 mg/m(2)/d due to grade 3 anemia in 50 % of patients. TRC102 exposure increased in proportion to dose with a mean t1/2 of 28 h. A pharmacodynamic assay confirmed that TRC102 binds to pemetrexed-induced AP sites at all doses studied. Stable disease or better was achieved in 15 of 25 patients evaluable for response (60 %), including one patient with recurrent metastatic oropharyngeal carcinoma that expressed high levels of thymidylate synthase, who achieved a partial response and was progression free for 14 months. CONCLUSIONS: When administered with pemetrexed, the maximum tolerated dose of oral TRC102 is 60 mg/m(2)/d for 4 days. Randomized controlled studies are planned to evaluate the clinical benefit of adding TRC102 to pemetrexed and other agents that induce BER.

Phase II clinical trial of cediranib in patients with metastatic castration-resistant prostate cancer.

OBJECTIVE: To assess the efficacy and toxicity of cediranib, a highly potent inhibitor of vascular endothelial growth factor receptor tyrosine kinases, in patients with metastatic castration-resistant prostate cancer (CRPC) previously treated with docetaxel-based therapy. PATIENTS AND METHODS: The study used a Simon two-stage trial design, which required at least two of 12 patients in the first cohort to be progression-free at 6 months. We enrolled a total of 35 evaluable patients who all received cediranib 20 mg orally daily. In a second cohort, 23 additional patients received prednisone 10 mg daily with cediranib. Endpoints included tumour response, progression-free survival (PFS), overall survival (OS), vascular permeability via dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), and toxicity. RESULTS: A total of 59 patients were enrolled, of whom 67% had received two or more previous chemotherapy regimens. Six of 39 patients with measurable disease had confirmed partial responses and one had an unconfirmed partial response. At 6 months, 43.9% of patients were progression-free; the median PFS and OS periods for all patients were 3.7 months and 10.1 months, respectively. We found that the DCE-MRI variables baseline transport constant (Ktrans ) and rate constant at day 28 were significantly associated with PFS in univariate analyses, but only baseline Ktrans remained significant when considered jointly. The most frequent toxicities were hypertension, fatigue, anorexia and weight loss; the addition of prednisone reduced the incidence of constitutional toxicities. CONCLUSION: This study demonstrated that cediranib was generally well tolerated with some anti-tumour activity in highly pretreated patients with metastatic CRPC who had progressive disease after docetaxel-based therapy.

Biphasic burst and sustained transdermal delivery in vivo using an AI-optimized 3D-printed MN patch.

The objective of the present study was to fabricate microneedles for delivering lipophilic active ingredients (APIs) using digital light processing (DLP) printing technology and quality by design (QbD) supplemented by artificial intelligence (AI) algorithms. In the present study, dissolvable microneedle (MN) patches using ibuprofen (IBU) as a model drug were successfully fabricated with DLP printing technology at âˆ¼ 750 µm height, ∼250 µm base diameter, and tip with radius of curvature (RoC) of âˆ¼ 15 µm. MN patches were comprised of IBU, photoinitiator, Lithium phenyl (2,4,6-trimethylbenzoyl) phosphinate (LAP), polyethylene glycol dimethacrylate (PEGDAMA)550 and distilled water and were developed using the QbD optimization approach. Optimization of print fidelity and needle morphology were achieved using AI implementing a semi-supervised machine learning approach. Mechanical strength tests demonstrated that IBU MNs formed pores both on Parafilm M® and human cadaver skin. IBU-MNs consisting of 0.23 %w/v and 0.49 %w/v LAP with 10 %w/v water showed âˆ¼ 2 mg/cm2 sustained drug permeation at 72 h in skin permeation experiments with flux of âˆ¼ 40 µg/cm2/h. Pharmacokinetic studies in rats displayed biphasic rapid first-order absorption with sustained zero-order input of Ko = 150ug/hr, AUC0-48h = 62812.02 ± 11128.39 ng/ml*h, Tmax = 2.66 ± 1.12 h, and Cmax = 3717.43 ± 782.25 ng/ml (using 0.23 %w/v LAP IBU MN patch). An in vitro in vivo relation (IVIVR) was conducted identifying a polynomial relationship between patch release and fraction absorbed in vivo. This study demonstrates fabrication of dissolvable DLP-printed microneedle patches for lipophilic API delivery with biphasic rapid first-order and sustained zero-order release.

Racial disparities in the association between variants on 8q24 and prostate cancer: a systematic review and meta-analysis.

Recent studies implicate single nucleotide polymorphisms (SNPs) within the 8q24 region as a risk factor for prostate cancer (PCa). New developments suggest that 8q24 encodes regulators of the nearby MYC gene, a known oncogene. In order to better understand the implications of SNPs in this region, we performed meta-analyses, stratified by race, of seven SNPs and one microsatellite marker previously identified as risk loci on the 8q24 region of the genome. In addition, we reviewed the literature examining the possible associations between these polymorphisms and clinicopathological features of PCa. The results of the meta-analyses indicate that rs6983267, rs1447295, rs6983561, rs7837688, rs16901979, and DG8S737 are significantly associated with a higher risk for PCa for at least one race, whereas the variants rs13254738 and rs7000448 are not. The degree of association and frequency of the causative allele varied among men of different races. Though several studies have demonstrated an association between certain 8q24 SNPs and clinicopathological features of the disease, review of this topic revealed conflicting results.

Methylation at CpG sites related to growth differentiation factor-15 was not prospectively associated with cardiovascular death in discordant monozygotic twins.

Myocardial infarction patients had decreased methylation at four growth differentiating factor-15 (GDF-15) related CpG sites (cg13033858, cg16936953, cg17150809, and cg18608055). These sites had not been studied for their association with cardiovascular disease (CVD) deaths. Thus, we aimed to assess the associations independent of genes, shared environment, and traditional CVD risk factors. Nineteen white, male, monozygotic twin pairs discordant for CVD deaths were included from the National Heart, Lung and Blood Institute Twin Study (NHLBI) initiated in 1969. Data on vital status was collected through December 31, 2014. Methylation of buffy coat DNA at exam 3 (1986-87) was measured using the Illumina HumanMethylation450 BeadChip. Principal component analysis was used to generate a score representing blood leukocyte composition and baseline CVD risk factors and predominated with natural killer cells, CD4+ T cells, and Framingham risk score. Conditional logistic regression demonstrated that methylation at the four CpG sites was not associated with CVD deaths before (all p > 0.05, bootstrapped p > 0.05) and after adjustment for the score (all p > 0.05). Joint influences of cg16936953 and the score were statistically significant (p < 0.05). In conclusion, joint influences of methylation at the site cg16936953 and the score are prospectively associated with CVD deaths independent of germline and common environment.ClinicalTrials.gov Identifier for NHLBI Twin Study: NCT00005124.

Simultaneous RP-HPLC-DAD quantification of bromocriptine, haloperidol and its diazepane structural analog in rat plasma with droperidol as internal standard for application to drug-interaction pharmacokinetics.

A simple and rapid RP-HPLC-DAD method was developed and validated for simultaneous determination of the dopamine antagonists haloperidol, its diazepane analog, and the dopamine agonist bromocriptine in rat plasma, to perform pharmacokinetic drug-interaction studies. Samples were prepared for analysis by acetonitrile (22.0 microg/mL) plasma protein precipitation with droperidol as an internal standard, followed by a double-step liquid-liquid extraction with hexane : chloroform (70:30) prior to C-18 separation. Isocratic elution was achieved using a 0.1% (v/v) trifluoroacetic acid in deionized water, methanol and acetonitrile (45/27.5/27.5, v/v/v). Triple-wavelength diode-array detection at the lambda(max) of 245 nm for haloperidol, 254 nm for the diazepane analog and droperidol, and 240 nm for bromocriptine was carried out. The LLOQ of DAL, HAL, and BCT were 45.0, 56.1, and 150 ng/mL, respectively. In rats, the estimated pharmacokinetic parameters (i.e., t(1/2), CL, and V(ss)) of HAL when administered with DAL and BCT were t(1/2) = 16.4 min, V(ss) = 0.541 L/kg for HAL, t(1/2) = 28.0 min, V(ss) = 2.00 L/kg for DAL, and t(1/2) = 24.0 min, V(ss) = 0.106 L/kg for BCT. The PK parameters for HAL differed significantly from those previously reported, which may be an indication of a drug-drug interaction.

Utility of oxcarbazepine in the treatment of childhood and adolescent psychiatric symptoms.

The primary aims of this study were to determine if oxcarbazepine is a safely tolerated option for treatment of psychiatric symptoms in children and whether its use facilitates dose modification of other psychotropic medications. A retrospective chart review was completed using data extracted from the electronic medical record of a large outpatient child psychiatry clinic. A total of 507 of 740 children prescribed oxcarbazepine for psychiatric indications for 3 months or more had adequate data to assess clinical responses and medication outcomes. Most patients prescribed oxcarbazepine experienced clinically significant control of irritability/anger, mood stabilization, aggressive outbursts, impulsivity, or anxiety, with over 80% achieving at least maintenance symptom control. In all, 51% and 25% fully discontinued second- or third-generation antipsychotic or antidepressant medication, respectively, after starting oxcarbazepine; 8% discontinued oxcarbazepine for nonresponse, while 9% stopped oxcarbazepine because of emergent side effects. In patients fully discontinuing or reducing the second- or third-generation antipsychotic dose by 50% or more, improvements in body mass index were observed. Oxcarbazepine may prove to be an appropriate alternative to antipsychotic and antidepressant medications for treating psychiatric symptoms in children and adolescents. In particular, it may be a more metabolically neutral psychotropic medication.

Formulation, Pharmacokinetic, and Efficacy Studies of Mannosylated Self-Emulsifying Solid Dispersions of Noscapine.

PURPOSE: To formulate hydroxypropyl methylcellulose-stabilized self-emulsifying solid dispersible carriers of noscapine to enhance oral bioavailability. METHODS: Formulation of noscapine (Nos) self-emulsifying solid dispersible microparticles (SESDs) was afforded by emulsification using an optimized formula of Labrafil M1944, Tween-80, and Labrasol followed by spray-drying with hydroxypropyl methylcellulose (HPMC), with and without mannosamine (Mann-Nos_SESDs and Nos_SESDs respectively); self-microemulsifying liquid dispersions (SMEDDs) with and without mannosamine (Mann-Nos_SMEDDs and Nos_SMEDDs respectively) were also prepared. SMEDDs and SESDs were characterized for size, polydispersity, surface charge, entrapment efficiency, in vitro permeability, in vitro release kinetics, and oral pharmacokinetics in Sprague-Dawley rats (10 mg/kg p.o). The antitumor efficacy of Mann-Nos_SESDs on the basis of chemosensitization to cisplatin (2.0 mg/kg, i.v.) was investigated in a chemorefractory lung tumor Nu/Nu mouse model up to a maximal oral dose of 300 mg/kg. RESULTS: The oil/surfactant/co-surfactant mixture of Labrafil M1944, Tween-80, and Labrasol optimized at weight ratios of 62.8:9.30:27.90% produced stable self-microemulsifying dispersions (SMEDDs) at a SMEDD to water ratio of 1-3:7-9 parts by weight. SMEDDs had hydrodynamic diameters between 231 and 246 nm; surface charges ranged from -16.50 to -18.7 mV; and entrapment efficiencies were between 32 and 35%. SESDs ranged in size between 5.84 and 6.60 µm with surface charges from -10.62 to -12.40 mV and entrapment efficiencies of 30.96±4.66 and 32.05±3.72% (Nos_SESDs and Mann-Nos_SESDs respectively). Mann-Nos_SESDs exhibited saturating uptake across Caco-2 monolayers (Papp = 4.94±0.18 × 10(-6) cm/s), with controlled release of 50% of Nos in 6 hr at pH 6.8 following Higuchi kinetics. Mann-Nos_ SESDs was 40% more bioavailable compared to Nos_SESDs; and was effective in sensitizing H1650 SP cells to Cisplatin in vitro and in an orthotopic lung tumor model of H1650 SP origin. CONCLUSIONS: Mannosylated noscapine self-emulsifying solid dispersions (Mann-Nos_SESDs) are bioavailable and potentiate the antineoplastic effect of cisplatin-based chemotherapy in cisplatin-resistant NSCLC.

Toward RNase inhibitors: thermodynamics of 2'-CMP/RNase-A binding in multi-ion buffer.

Certain ribonucleases (RNases), such as eosinophil-derived neurotoxin, are associated with pathological conditions (e.g. asthma and inflammatory bowel disease) and can even be overtly cyto(neuro)toxic. It has been proposed that small-molecule inhibitors should have therapeutic utility. We used isothermal titration microcalorimetry to characterize reversible inhibitor cytidine 2'-monophosphate (2'-CMP) binding to RNase-A in a multi-ion buffer at 37 degrees as a representative system. The estimated parameters were: K(d)=13.9 microM; DeltaG degrees =-6.90 kcal/mol; DeltaH degrees =-15.7 kcal/mol; and DeltaS degrees =-0.028 kcal/mol-K ('enthalpy-driven' interaction). These data should assist drug design of small-molecule inhibitors of homologous RNase catalytic domains.

Protonation effect on drug affinity.

Pharmacologic ligand-macromolecule interactions are commonly characterized by affinity (dissociation) constants such as K(d) or K(i) without regard to the protonation effect of the buffer used in the measurement. The protonation effect is demonstrated here using isothermal titration microcalorimetry measurements of the competitive inhibitor binding of cytidine 2'-monophosphate (2'-CMP) to RNase-A as a model system in buffers of different ionization Delta H(buffer). The results demonstrate the importance of protonation in measures of affinity.

Development of a novel approach to enhance the solubility of ftibamzone formulation.

Ftibamzone (FBZ) is known to be effective against herpes simplex virus that causes genital herpes but poor solubility of FBZ has reduced its therapeutic efficacy. We investigated water-soluble complexes of various nanoparticles with FBZ to improve its solubility as well as increase its absorption. Using phase-solubility technique, we measured formation constant (K1:1 and K1:2) values at room temperature in pH 7 buffer. Solubility was determined by dissolving FBZ or FBZ-entrapped nanoparticles in phosphate buffers and pH adjusted to different pH range (2-12). The solutions were then equilibrated for 24 hours and then filtered and analyzed using HPCL. Nanoparticles were formulated using nanoprecipitation technique and cellular uptake of nanoparticle was determined by confocal microscope. No significant FBZ solubility was observed from pH 2 to 10 however we did notice a rapid increase in solubility from pH of 10 to 12 with FBZ solubility of 950 µg/ml. Our log D against pH profile revealed that FBZ is characteristic of an acid drug since unionized group was dominant at low pH. FBZ interaction with methyl-ß-cyclodextrin (mßCD) complexation/nanoparticles showed a greater solubility of FBZ compared with FBZ alone while complexation constants were determined to be K1:1 and K1:2 were 7.06×10-3 and 8.98×10-8 mM-1 respectively. Only FBZ-chitosan nanoparticles were toxic against MDCK cells. Study demonstrates that FBZ-PLGA nanoparticles could significantly enhance the solubility and absorption of FBZ compared with FBZ alone and has the potential to be used as an effective delivery system for the treatment of genital herpes.

A rapid ultra HPLC-MS/MS method for the quantitation and pharmacokinetic analysis of 3-deazaneplanocin A in mice.

3-Deazaneplanocin A (DZNep) has been shown to have anti-cancer activity in numerous cancer types and its continued preclinical, and eventual clinical, drug development will require rapid and sensitive bioanalytical methods in order to quantitate this drug for pharmacokinetic analyses. The ultra HPLC with positive thermospray tandem mass spectrometric (LC-MS/MS) detection affords the most sensitive (limit of quantitation 5ng/mL) and rapid (3min run time) bioanalytical method to date for DZNep. Due to the polar nature of this drug and the internal standard (tubercidin), a hydrophilic-interaction column (HILIC) was used. The method was accurate, with less than 10% deviation from nominal values, as well as precise, where both within-day and between-day precisions were less than 15%. A liquid-liquid extraction procedure was able to recover ∼90% of drug from a small volume (50µL) of mouse plasma. This method was successfully applied to a pharmacokinetic study in mice intravenously injected with DZNep.