The goal of this study is to evaluate the stability of lyophilized siRNA formulations. The gene silencing efficiency of a stored lyophilized siRNA formulation (i.e. siRNA nanosomes) was evaluated in interferon-α (IFN-α) resistant hepatitis C virus (HCV) at different time points up to three months in an in vitro cell culture model and compared with freshly prepared siRNA formulations. Novel siRNA sequences were encapsulated within nanosize liposomes following condensation with protamine sulfate. The siRNA encapsulated nanosomes were lyophilized and stored at 4°C for 3 months, along with liquid liposomes (L) and lyophilized liposome powder (P) which were subsequently used to prepare siRNA nanosomes (L) and siRNA nanosomes (P), respectively at different time points. Physiochemical and biological properties of all three formulations were compared at different time points up to 3 months. The particle size of the stored siRNA nanosomes (642±25 nm) was considerably larger initially in comparison with the liquid liposomes (134±5 nm) and lyophilized liposomes (118±3). However, the particle size gradually became smaller over time (413±128 nm by the third month). The zeta potential of all three formulations was initially very high (> +40 mV), followed by a gradual decrease over time. The amount of siRNA in the stored siRNA nanosomes decreased ~ 18% during the 3 month storage period (1.16±0.03 nmol initially on day 1 vs. 0.95±0.04 nmol after 3 months). With respect to biological potency, all three formulations were significantly effective to knock-down HCV throughout the storage time. The cell viability was well-maintained throughout this period. Thus, this study indicates that the stored lyophilized siRNA formulation is as effective as the fresh preparation and that long-term storage could be a viable option to treat deadly diseases such as cancer and viral infection.
INTRODUCTION: PTG-200 (JNJ-67864238) is an oral peptide that acts locally in intestinal tissues to block IL-23 signaling by selectively binding the IL-23 receptor (IL-23R). The gastrointestinal (GI)-restriction of PTG-200 is demonstrated in vivo by marked drug concentrations in GI tissues and feces and limited systemic blood exposure. PTG-200 therapeutic potential was established in a rat model of TNBS-induced colitis, where its threshold concentration in colonic tissue and luminal feces associated with efficacy was determined to inform the human efficacious dose. 1 The objectives of this Phase 1 study were to assess safety, tolerability, and pharmacokinetics (PK) of PTG-200. METHODS: This first-in-human (FIH) Phase 1 study was a single-center, randomized, double-blind, placebo-controlled trial comprising single and 14-day multiple ascending dose (SAD and MAD) arms in 82 healthy male volunteers. Oral doses ranged from 150 mg to 900 mg once daily (QD, fasted or fed) or twice daily (BID, fed). Subjects were monitored for safety and tolerability. PK in plasma, urine and feces was evaluated. RESULTS: Oral administration of PTG-200 was well-tolerated. There were no serious adverse events, dose-limiting toxicities, or clinically significant adverse events. PTG-200 plasma exposure was low (Table 1), below that expected to result in systemic biological activity. Following single-dose oral administration under fasted conditions, plasma PTG-200 concentrations exhibited dose-related increases with a median time to maximal concentration (Tmax) at 2 h. Administration of a high-fat meal prolonged the median Tmax to 4 h and had a modest effect on peak concentration (Cmax) and estimated overall exposure. Repeat dosing led to dose-related increases in plasma exposure. Consistent with a terminal half-life of ∼1.5 h in plasma, PTG-200 showed no evidence of accumulation except for the 900 mg BID group. Fecal concentrations in several cohorts met or exceeded the targeted threshold concentration associated with efficacy as established using the preclinical colitis model. CONCLUSION: Orally administered PTG-200 was well-tolerated in this FIH study. Systemic PK was consistent with the GI-restricted design of PTG-200. These safety and PK characteristics, combined with fulfillment of fecal drug threshold concentrations, support further clinical development of PTG-200 for the treatment of IBD. A Phase 2 study in patients with moderate-to-severe Crohn's disease is planned.
Fenretinide is an effective anti-cancer drug with high in vitro cytotoxicity and low in vivo systemic toxicity. In clinical trials, fenretinide has shown poor therapeutic efficacy following oral administration – attributed to its low bioavailability and solubility. The long term goal of this project is to develop a formulation for the oral delivery of fenretinide. The purpose of this part of the study wasto prepare and characterize hydrophilic nanoparticle formulations of fenretinide. Three different ratios of polyvinyl pyrrolidone (PVP) to fenretinide were used, namely, 3:1, 4:1, and 5:1. Both drug and polymer were dissolved in a mixture of methanol and dichloromethane (2:23 v/v). Rotary evaporation was used to remove the solvents, and, following reconstitution with water, a high pressure homogenizer was used to form nanoparticles. The particle size and polydispersity index were measured before and after lyophilization. The formulations were studied by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and x-ray powder diffraction (XRPD). The effectiveness of the formulations was assessed by releasestudies and Caco-2 cell permeability assays. As the PVP content increased, the recovered particle size following lyophilization became more consistent with the pre-lyophilization particle size, especially for those formulations with less lactose. The DSC scans of the formulations did not show any fenretinide melting endotherms, indicating that the drug was either present in an amorphous form in the formulation or that a solid solution of the drug in PVP had formed. For the release studies, the highest drug release among the formulations was 249.2 ± 35.5 ng/mL for the formulation with 4:1 polymer-to-drug. When the permeability of the formulations was evaluated in a Caco-2 cell model, the mean normalized flux for each treatment group was significantly higher (p<0.05) from the fenretinide control. The formulation containing 4:1 polymer-to-drug ratio and 6:5 lactose-to-formulation ratio emerged as the optimal choice for further evaluation as a potential oral delivery formulation for fenretinide.
Afrezza is a safe and effective treatment for selected adults with type 1 or type 2 diabetes, potentially providing an alternative to injectable insulin for prandial blood glucose control.
Objective The purpose of this study is to develop a nanoemulsion formulation for its use as a transcutaneous vaccine delivery system. Materials and methods With bovine albumin-fluorescein isothiocyanate conjugate (FITC-BSA) as a vaccine model, formulations were selected with the construction of pseudo-ternary phase diagrams and a short-term stability study. The size of the emulsion droplets was furthered optimized with high-pressure homogenization. The optimized formulation was evaluated for its skin permeation efficiency. In vitro skin permeation studies were conducted with shaved BALB/c mice skin samples with a Franz diffusion cell system. Different drug concentrations were compared, and the effect of the nanoemulsion excipients on the permeation of the FITC-BSA was also studied. Results The optimum homogenization regime was determined to be five passes at 20 000 psi, with no evidence of protein degradation during processing. With these conditions, the particle diameter was 85.2 nm ± 15.5 nm with a polydispersity index of 0.186 ± 0.026 and viscosity of 14.6 cP ± 1.2 cP. The optimized formulation proved stable for 1 year at 4 °C. In vitro skin diffusion studies show that the optimized formulation improves the permeation of FITC-BSA through skin with an enhancement ratio of 4.2 compared to a neat control solution. Finally, a comparison of the skin permeation of the nanoemulsion versus only the surfactant excipients resulted in a steady state flux of 23.44 μg/cm2/h for the nanoemulsion as opposed to 6.10 μg/cm2/h for the emulsifiers. Conclusion A novel nanoemulsion with optimized physical characteristics and superior skin permeation compared to control solution was manufactured. The formulation proposed in this study has the flexibility for the incorporation of a variety of active ingredients and warrants further development as a transcutaneous vaccine delivery vehicle.
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