The management of retinoblastoma (RB) involves the use of invasive treatment regimens. Paclitaxel (PTX), an effective antineoplastic compound used in the treatment of a wide range of malignant tumors, poses treatment challenges due to systemic toxicity, rapid elimination, and development of resistance. The goal of this work was to develop PTX-loaded, α-tocopherol succinate (αTS)-based, nanostructured lipid carrier (NLCs; αTS-PTX-NLC) and PEGylated αTS-PTX-NLC (αTS-PTX-PEG-NLC) to improve ocular bioavailability. The hot homogenization method was used to prepare the NLCs, and repeated measures ANOVA analysis was used for formulation optimization. αTS-PTX-NLC and αTS-PTX-PEG-NLC had a mean particle size, polydispersity index and zeta potential of 186.2 ± 3.9 nm, 0.17 ± 0.03, −33.2 ± 1.3 mV and 96.2 ± 3.9 nm, 0.27 ± 0.03, −39.15 ± 3.2 mV, respectively. The assay and entrapment efficiency of both formulations was >95.0%. The NLC exhibited a spherical shape, as seen from TEM images. Sterilized (autoclaved) formulations were stable for up to 60 days (last time point checked) under refrigerated conditions. PTX-NLC formulations exhibited an initial burst release and 40% drug release, overall, in 48 h. The formulations exhibited desirable physicochemical properties and could lead to an effective therapeutic option in the management of RB.

Prostate cancer is the most common cancer and one of the leading causes of cancer deaths in men. One of the commonly used approaches to treat metastatic prostate cancer was via first‐generation nonsteroidal anti‐androgens (NSAAs), namely flutamide, nilutamide, bicalutamide and topilutamide. Most prostate cancer patients who are initially responsive develop the most aggressive form of disease called castration‐resistant prostate cancer. Second‐generation NSAA receptor antagonists (enzalutamide, apalutamide and darolutamide) are emerging as additional new options to treat castration‐resistant prostate cancer. The objective of this work was to review the literature on the bioanalytical methods for the quantification of first‐ and second‐generation NSAA inhibitors in clinical (human plasma) and preclinical (mouse plasma, rat plasma, urine and tissue homogenates etc.) studies along with relevant case studies for some chosen drugs. Based on the review, it was concluded that the published methodologies using either HPLC or LC–MS/MS are well suited for the quantification of NSAA inhibitors in various biological fluids to delineate pharmacokinetic data.

Human immunodeficiency virus (HIV) is associated with neuroendocrine dysfunction which may contribute to co-morbid stress-sensitive disorders. The hypothalamic-pituitary-adrenal (HPA) or -gonadal (HPG) axes are perturbed in up to 50% of HIV patients. The mechanisms are not known, but we have found the HIV-1 trans-activator of transcription (Tat) protein to recapitulate the clinical phenotype in male mice. We hypothesized that HPA and/or HPG dysregulation contributes to Tat-mediated interactions with oxycodone, an opioid often prescribed to HIV patients, in females. Female mice that conditionally-expressed the Tat_1–86 protein [Tat(+) mice] or their counterparts that did not [Tat(−) control mice] were exposed to forced swim stress (or not) and behaviorally-assessed for motor and anxiety-like behavior. Some mice had glucocorticoid receptors (GR) or corticotropin-releasing factor receptors (CRF-R) pharmacologically inhibited. Some mice were ovariectomized (OVX). As seen previously in males, Tat elevated basal corticosterone levels and potentiated oxycodone’s psychomotor activity in females. Unlike males, females did not demonstrate adrenal insufficiency and oxycodone potentiation was not regulated by GRs or CRF-Rs. Rather OVX attenuated Tat/oxycodone interactions. Either Tat or oxycodone increased anxiety-like behavior and their combination increased hypothalamic allopregnanolone. OVX increased basal hypothalamic allopregnanolone and obviated Tat or oxycodone-mediated fluctuations. Together, these data provide further evidence for Tat-mediated dysregulation of the HPA axis and reveal the importance of HPG axis regulation in females. HPA/HPG disruption may contribute vulnerability to affective and substance use disorders.

A simple, specific and reproducible high-performance liquid chromatography (HPLC) assay method has been developed and validated for the quantitation of second generation antiandrogens and their active metabolites namely apalutamide, enzalutamide, N-desmethylenzalutamide (active metabolite of enzalutamide), darolutamide and ORM-15341 (active metabolite of darolutamide) in mice plasma. The method involves extraction of apalutamide, enzalutamide, N-desmethylenzalutamide, darolutamide and ORM-15341 along with internal standard (IS) from 100 µL mice plasma through a simple protein precipitation process. The chromatographic analysis was performed on a Waters Alliance HPLC system using a gradient mobile phase (comprising 10 mM ammonium acetate and acetonitrile in a flow-gradient) and X-Terra Phenyl column. The UV detection wave length was set at λ_max 250 nm. Apalutamide, enzalutamide, N-desmethylenzalutamide, darolutamide and ORM-15341 and the IS eluted at 13.6, 11.4, 9.68, 6.11, 6.93 and 4.69 min, respectively with a total run time of 15 min. Method validation was performed as per regulatory guidelines and the results met the acceptance criteria. The calibration curve was linear over a concentration range of 209 – 5215 ng/mL (r ²=0.998). The intra- and inter-day precisions were in the range of 0.56–13.5 and 1.04–13.9%, respectively. The validated HPLC method was successfully applied to a pharmacokinetic study in mice.

SAFit-1 and SAFit-2 are selective FKBP51 (FK506-binding protein 51) ligands. In this paper, we present the development and validation data of an LC-MS/MS method for the simultaneous quantitation of SAFit-1 and SAFit-2 in mice plasma as per FDA regulatory guideline. SAFit-1 and SAFit-2 along with internal standard were extracted from mice plasma using liquid-liquid extraction method. Chromatographic resolution of SAFit-1, SAFit-2 and the internal standard (warfarin) was achieved on an X-Terra phenyl column using 0.2% formic acid:acetonitrile (20:80, v/v) as an eluent, which was delivered at a flow-rate of 0.9 mL/min. The MS/MS ion transitions monitored were m/z 748.4→420.4, 803.7→384.3 and 309.2 →163.2 for SAFit-1, SAFit-2 and the internal standard, respectively. The linearity range was 2.45–2446 ng/mL for both SAFit-1 and SAFit-2. The intra- and inter-day accuracy and intra- and inter-day precision were in the range of 0.90–1.07 and 2.38–10.8%, respectively for SAFit-1; 0.97–1.15 and 0.23–12.5%, respectively for SAFit-2. Both SAFit-1 and SAFit-2 were found to be stable in stability studies (up to three freeze-thaw cycles and for long-term at −80°C for 30 days) and processed (bench-top for 3 h and in in-injector for 16 h) samples. The application of the validated method was shown in a pharmacokinetic study in mice.

Modulation of the endocannabinoid system (ECS) is of great interest for its therapeutic relevance in several pathophysiological processes. The CB2 subtype is largely localized to immune effectors, including microglia within the central nervous system, where it promotes anti-inflammation. Recently, a rational drug design toward precise modulation of the CB2 active site revealed the novelty of Pyrrolo[2,1-c][1,4]benzodiazepines tricyclic chemotype with a high conformational similarity in comparison to the existing leads. These compounds are structurally unique, confirming their chemotype novelty. In our continuing search for new chemotypes as selective CB2 regulatory molecules, following SAR approaches, a total of 17 selected (S,E)-11-[2-(arylmethylene)hydrazono]-PBD analogs were synthesized and tested for their ability to bind to the CB1 and CB2 receptor orthosteric sites. A competitive [³H]CP-55,940 binding screen revealed five compounds that exhibited >60% displacement at 10 μM concentration. Further concentration-response analysis revealed two compounds, 4k and 4q, as potent and selective CB2 ligands with sub-micromolar activities (K_i = 146 nM and 137 nM, respectively). In order to support the potential efficacy and safety of the analogs, the oral and intravenous pharmacokinetic properties of compound 4k were sought. Compound 4k was orally bioavailable, reaching maximum brain concentrations of 602 ± 162 ng/g (p.o.) with an elimination half-life of 22.9 ± 3.73 h. Whether administered via the oral or intravenous route, the elimination half-lives ranged between 9.3 and 16.7 h in the liver and kidneys. These compounds represent novel chemotypes, which can be further optimized for improved affinity and selectivity toward the CB2 receptor.