Engineering of polymer–surfactant nanoparticles of doxycycline hydrochloride for ocular drug delivery

Abstract

Context: Physiologic barriers of the eye, short precorneal drug residence time and poor corneal penetration are the few reasons for reduced ocular bioavailability.

Objective: This study was aimed to develop novel polymer–surfactant nanoparticles of hydrophilic drug doxycycline hydrochloride (DXY) to improve precorneal residence time and drug penetration.

Materials and methods: Nanoparticles were formulated using emulsion cross-linking method and the formulation was optimized using factorial design. The prepared formulation was characterized for particle size, ζ potential, encapsulation efficiency, in vitro drug release and ex vivo drug diffusion studies. The antibacterial activity studies were also carried out against Escherichia coli and Staphylococcus aureus using the cup-plate method. In vivo eye irritation study was carried out by a modified Draize test in rabbits.

Results and discussion: The particle size was found to be in the range of 331–850?nm. About 45–80% of the drug was found to be encapsulated in the nanoparticles. In vitro release demonstrated sustained release profile. Lower flux values in case of nanoparticles as compared to DXY pure drug solution in ex vivo diffusion studies confirmed the sustained release. The nanoparticles were found to be significantly effective (p?<?0.001) than DXY aqueous solution due to sustained release of doxycycline from nanoparticles in both the E. coli and S. aureus strains. The formulation was found to be stable over entire stability period.

Conclusion: The developed formulation is safe and suitable for sustained ocular drug delivery.     

Immune checkpoint inhibitors in patients with solid tumors and poor performance status: A prospective data from the real-world settings

Immune checkpoint inhibitors (ICIs) are rapidly being incorporated as treatment option either alone or in combination with chemotherapy in most of the solid tumors. Since there is very limited data of ICI in patients with poor performance status (PS) from the real world settings, we performed a retrospective audit of patients who received ICI and report the analysis based on ECOG PS of these patients.This study is a retrospective audit of a prospectively collected database of patients receiving ICIs for advanced solid tumors in any line between August 2015 and November 2018 at Tata Memorial Hospital, Mumbai, India. All statistical calculations were performed using SPSS statistical software for windows version 20.0.A total of 155 patients who received ICIs during the specified period were evaluated for this study. Baseline ECOG PS 0–1 (n = 103, 66.4%) patients was associated with median OS 9.1 (95% CI [confidence interval], 4.4-NR) months when compared to ECOG 2–4 (n = 52, 33.5%) which had a median OS of 2.9 (95% CI; 1.8–5.5) months (HR, 1.7, 95% CI, 1.1–2.7, log rank P = .017). The disease control rate for the poor PS group was 34.6%. However, 27.3% patients (95% CI: 20.3–34.3) were still alive at 1 year. Median OS in patients with PS 2 was 3.7 months (95% CI: 0–11.6) as compared to 1.8 months (95% CI: 0.2–3.4) for those with PS 3–4 (HR-2.0; 95% CI: 1.0–3.9, P = .041). The tolerance to ICIs was good with no grade 3/4 toxicities in 44 (84.6%) patients.Immune checkpoint inhibitors are a safe and effective therapeutic option even in solid tumor patients with poor performance status.     

Preclinical to Clinical Translation of CNS Transporter Occupancy of TD-9855, a Novel Norepinephrine and Serotonin Reuptake Inhibitor

Background:

Monoamine reuptake inhibitors exhibit unique clinical profiles that reflect distinct engagement of the central nervous system (CNS) transporters.

Methods:

We used a translational strategy, including rodent pharmacokinetic/pharmacodynamic modeling and positron emission tomography (PET) imaging in humans, to establish the transporter profile of TD-9855, a novel norepinephrine and serotonin reuptake inhibitor.

Results:

TD-9855 was a potent inhibitor of norepinephrine (NE) and serotonin 5-HT uptake in vitro with an inhibitory selectivity of 4- to 10-fold for NE at human and rat transporters. TD-9855 engaged norepinephrine transporters (NET) and serotonin transporters (SERT) in rat spinal cord, with a plasma EC₅₀ of 11.7ng/mL and 50.8ng/mL, respectively, consistent with modest selectivity for NET in vivo.Accounting for species differences in protein binding, the projected human NET and SERT plasma EC₅₀ values were 5.5ng/mL and 23.9ng/mL, respectively. A single-dose, open-label PET study (4–20mg TD-9855, oral) was conducted in eight healthy males using the radiotracers [¹¹C]-3-amino-4- [2-[(di(methyl)amino)methyl]phenyl]sulfanylbenzonitrile for SERT and [¹¹C]-(S,S)-methylreboxetine for NET. The long pharmacokinetic half-life (30–40h) of TD-9855 allowed for sequential assessment of SERT and NET occupancy in the same subject. The plasma EC₅₀ for NET was estimated to be 1.21ng/mL, and at doses of greater than 4mg the projected steady-state NET occupancy is high (>75%). After a single oral dose of 20mg, SERT occupancy was 25 (±8)% at a plasma level of 6.35ng/mL.

Conclusions:

These data establish the CNS penetration and transporter profile of TD-9855 and inform the selection of potential doses for future clinical evaluation.     

Interactions between host and gut microbiota in domestic pigs: a review

ABSTRACT

It is well established that pig gut microbiota plays a critical role in maintaining metabolic homeostasis as well as in a myriad of physiological, neurological and immunological functions; including protection from pathogens and digestion of food materials – some of which would be otherwise indigestible by the pig. A rich and diverse gut microbial ecosystem (balanced microbiota) is the hallmark of good health; while qualitative and quantitative perturbations in the microbial composition can lead to development of various diseases. Alternatively, diseases caused by stressors or other factors have been shown to negatively impact the microbiota. This review focuses primarily on how commensal microorganisms in the gastrointestinal tract of pigs influence biochemical, physiological, immunological, and metabolic processes within the host animal.     

Ultrasensitive and bifunctional ZnO nanoplates for an oxidative electrochemical and chemical sensor of NO2: implications towards environmental monitoring of the nitrite reaction

Herein, we focused on the one pot synthesis of ZnO nanoplates (NP edge thickness of ∼100 nm) using a chemical emulsion approach for chemical (direct) and electrochemical (indirect) determination of NO₂. The structural and morphological elucidation of the as-synthesized ZnO NPs was carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis of X-ray (EDAX), thermogravimetric analysis (TGA) and BET-surface area measurements. The XRD studies of the as-synthesised NPs reveal that ZnO NPs have a Wurtzite type crystal structure with a crystallite size of ∼100 nm. Such ZnO NPs were found to be highly sensitive to NO₂ gas at an operating temperature of 200 °C. Electrocatalytic abilities of these ZnO NPs towards NO₂/NO₂⁻ were verified through cyclic voltammetry (CV) and linear sweep voltammetry (LSV) using aqueous 1 mM NO₂⁻ (nitrite) in phosphate buffer (pH 7) solution. The results revealed enhanced activity at an onset potential of 0.60 V vs. RCE, achieved at a current density of 0.14 mA cm⁻². These ZnO NPs show selective NO₂ detection in the presence of other reactive species including CO, SO₂, CH₃OH and Cl₂. These obtained results show that this chemical route is a low cost and promising method for ZnO NPs synthesis and recommend further exploration into its applicability towards tunable electrochemical as well as solid state gas sensing of other toxic gases.

Herein, we focused on the one pot synthesis of ZnO nanoplates (NP edge thickness of ∼100 nm) using a chemical emulsion approach for chemical (direct) and electrochemical (indirect) determination of NO₂.      

Energy Consumption and Sensitivity Analysis of Rainfed Chickpea Production in Vertisols of Semi-arid Karnataka

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - In-situ rainwater conservation improves chickpea productivity in Vertisols. This hypothesis was tested by...     

Tumorigenic effect of 4-methylphenylhydrazine hydrochloride in Swiss mice

Summary 4-Methylphenylhydrazine hydrochloride was administered as 10 weekly subcutaneous injections of 140 g/g body weight and as 7 weekly intragastric instillations of 250 g/g body weight in physiological saline to randomly bred Swiss mice. Treatments given subcutaneously resulted in induction of lung tumors in incidences of 36% in females and 44% in males, while intragastric treatment caused a 40% incidence in females. In addition, it gave rise to blood vessel tumors by intragastric route in incidences of 32% in females and 18% in males. In the two physiological saline-treated control groups, the lung tumor incidence (combined) was 20% in females and 21% in males, while the blood vessel tumor incidence (combined) was 7% in females and 6% in males. Histopathologically, the lesions were classified as adenomas and adenocarcinomas of the lungs, and angiomas and angiosarcomas of blood vessels.4-Methylphenylhydrazine was postulated to be a metabolite of 4-hydroxymethylphenylhydrazine, an ingredient of the commonly eaten mushroom Agaricus bisporus. The implications are discussed with respect to the tumorigenesis data.This study was supported by Public Health Service Contract NOl CP33278 from the National Cancer Institute, NIH, USA