Amoxapine-Loaded Solid Lipid Nanoparticles with Superior Preclinical Pharmacokinetics for Better Brain Delivery: LC-MS/MS and GC-MS Analysis.

The tricyclic antidepressant amoxapine (AMX) has been reported for a rapid onset of action compared to other cyclic antidepressants. It has very low solubility and bioavailability due to first-pass metabolism. Therefore, we planned to develop solid lipid nanoparticles (SLNs) of AMX using a single emulsification method to increase its solubility and bioavailability. HPLC and LC-MS/MS methods were developed further to quantify AMX in the formulation, plasma, and brain tissue samples. The formulation was studied for entrapment efficiency, loading, and in vitro drug release. Particle size and ζ potential analyses, AFM, SEM, TEM, DSC, and XRD were used for further characterization. In vivo oral pharmacokinetic and brain pharmacokinetic studies were performed using Wistar rats. The entrapment and loading efficiencies of AMX in SLNs were 85.8 ± 3.42 and 4.5 ± 0.45%, respectively. The developed formulation had a mean particle size of 151.5 ± 7.02 nm and a polydispersity index of 0.40 ± 0.11. DSC and XRD results indicated that AMX was incorporated into the nanocarrier system in an amorphous form. SEM, TEM, and AFM studies of AMX-SLNs confirmed the particles' spherical shape and nanoscale size. AMX solubility increased by approx. 2.67 times compared to the pure drug. The developed LC-MS/MS method was successfully applied to the oral and brain pharmacokinetic study of AMX-loaded SLNs in rats. Oral bioavailability was enhanced 1.6 times compared to the pure drug. The peak plasma concentrations of pure AMX and AMX-SLNs were 617.4 ± 137.4 and 1043.5 ± 150.2 (ng/mL), respectively. AMX-SLNs showed more than 5.8 times brain concentration compared to the pure drug. Based on the findings, it appears that utilizing a solid lipid nanoparticle carrier to transport AMX can be a highly effective delivery method with improved pharmacokinetic properties in the brain. This approach may prove valuable for future antidepressant treatment.

Simultaneous Method Development and Validation of Anastrozole Along with Piperine: Degradation Studies and Degradants Characterization Using LC-QTOF-ESI-MS Along with In-silico ADMET Predictions.

BACKGROUND: Anastrozole (ATZ) is a selective non-steroidal inhibitor widely used for the treatment of breast cancer in post-menopausal women. ATZ exerts its biological activity by inhibiting the enzyme aromatase, which is responsible for converting androgens to estrogens. Piperine (PIP), a natural alkaloid and the main component of black pepper, is used as a bioenhancer and for combating a variety of health issues ranging from upset stomach to dental problems. INTRODUCTION: ATZ has been reported to have poor water solubility and less bioavailability. The novel combination of ATZ and PIP was proposed to enhance the bioavailability of both the compounds. However, there are no reported studies on the simultaneous estimation of ATZ and PIP as well as stability studies to explore their potential interactions and degradation profiling. METHOD: A simple, accurate, precise, robust, sensitive, reliable, and economic analytical method for the simultaneous estimation of ATZ and PIP was developed using acetonitrile and water (60:40) as the mobile phase. Forced degradation studies and characterization of degradants were performed, and degradants were identified for molecular weight using LC-QTOF-ESI-MS; the structures of degradants were confirmed with mass accuracy measurements. The mechanism of each degradant has also been described in more detail in the manuscript. RESULTS AND CONCLUSION: A total of fourteen degradants were characterized and reported for their good human oral absorption. A precise, robust, accurate, cheap, and sensitive RP-HPLC-DAD simultaneous method for the estimation of ATZ and PIP has been developed. From the future point of view, there is huge scope to conduct pharmacological, pharmacodynamic, and drug-herb interaction studies based on this fruitful outcome. All the degradants may be screened against MDR-resistant breast cancer in the future to check their potential as a drug target.

Preparation and characterization of amoxapine- and naringin-loaded solid lipid nanoparticles: drug-release and molecular-docking studies.

Aim: Amoxapine (AMX) has been reported to be metabolized by CYP3A4 and CYP2D6. Naringin (NG) has been reported to inhibit CYP enzymes. Therefore, the current work was designed to develop AMX solid lipid nanoparticles (AMX-SLNs) and NG-SLNs for better therapeutic performance. Materials & methods: AMX-SLNs and NG-SLNs were prepared and characterized. AMX and NG interactions with CYP450s were studied with molecular docking to rationalize the effectiveness of the combination. Results: AMX-SLNs and NG-SLNs showed nanometric size with a sustained in vitro drug-release profile. NG showed a higher predicted binding affinity for CYP3A4 and CYP2D6, suggesting the potential for inhibition. Conclusion: The developed formulations were thoroughly characterized along with molecular docking data indicating promising AMX and NG combinations that may show good therapeutic activity.

Process development for the total synthesis of the novel drug metabolite Carboxy toremifene as a standard reference material along with characterization and purity assessment for the Antidoping quality Control Purposes.

Tamoxifen and toremifene are two selective estrogen receptor modulators (SERMs) commonly used to treat breast cancer in women. Toremifene is well-known as a triphenylethylene derivative. Carboxy toremifene is a common metabolite of toremifene and tamoxifen. Since 2005, the World Anti-Doping Agency (WADA) has banned the SERMs category during in and out of competition. These substances are in the S4 category in the WADA prohibited list as "agents with anti-oestrogenic activity." However, there is no commercially accessible carboxy toremifene reference material in the market. This research highlights the novel synthetic procedure, the development of a carboxy toremifene HPLC method, and validation, along with detailed characterization using advanced analytical techniques using 1 H NMR, HRMS, FT-IR-ATR and UV-visible spectroscopy. RP-HPLC-DAD method was developed and validated to assess the purity of carboxy toremifene. Developed reference material has shown 100% purity. Therefore, we recommend that this synthesized carboxy toremifene may be used as reference material to strengthen the WADA-accredited lab to maintain a clean sports mission during sports competitions.

Analytical developments of p-hydroxy prenylamine reference material for dope control research: Characterization and purity assessment.

Prenylamine was initially used for the treatment of angina pectoris and later on withdrawn from the market in 1988 due to cardiac arrhythmias concern. The major phase I metabolite of prenylamine is p-hydroxy prenylamine that has a chiral center in the structure. Even though p-hydroxy prenylamine was synthesized earlier, it lacked complete analytical developments for chiral high-performance liquid chromatography (HPLC) separation. However, p-hydroxy prenylamine reference material is not commercially available. The innovation of this manuscript is the development and validation of a chiral HPLC separation method and more extensive characterization of the reference material than previously reported method. Therefore, it was hypothesized to develop and validate normal phase HPLC method for p-hydroxy prenylamine reference material. p-Hydroxy prenylamine was synthesized in two batches and characterized successfully using 13 C NMR, 1 H NMR, high-resolution mass spectrometry (HRMS), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). A normal phase chiral HPLC method was developed to analyze the p-hydroxy prenylamine purity. Separation of the p-hydroxy prenylamine enantiomers were achieved using ultra-high-performance liquid chromatography (UHPLC) on a ChiralCel ODH column at wavelength of 220 nm. The developed method was validated in terms of its linearity, accuracy, precision, and robustness for purification, purity assessment, and stability studies. Proton and carbon peaks were confirmed by nuclear magnetic resonance (NMR) analysis. Functional groups were confirmed by FT-IR. Loss on drying was 0.3% and 0.6% for Batches 1 and 2, respectively. The purity of the developed reference material for Batches 1 and 2 was found to be 99.59% and 100%, respectively. Therefore, the synthesized batches of p-hydroxy prenylamine can be used in dope testing as reference material.