Sustained Plasma Levels Research Articles

A novel methionyl-tRNA synthetase inhibitor targeting gram-positive bacterial pathogens.

New antibiotics are needed to treat gram-positive bacterial pathogens. MRS-2541 is a novel inhibitor of methionyl-tRNA synthetase with selective activity against gram-positive bacteria. The minimum inhibitory concentrations (MICs) against Staphylococcus aureus, Streptococcus pyogenes, and Enterococcus species range from 0.063 to 0.5 µg/mL. Given orally to mice at 50 mg/kg every 8 hours, MRS-2541 shows sustained plasma levels well above these MICs. In the mouse thigh infection model, MRS-2541 decreased methicillin-resistant Staphylococcus aureus and Streptococcus pyogenes bacterial loads to the same degree as linezolid. MRS-2541 is a promising new antibiotic for development against skin and soft tissue infections.

Abstract C027: Efficacy advantages of a novel pan-RAS inhibitor, ADT-1004, over mutant- specific KRAS inhibitors for suppressing pancreatic tumor growth in murine models

Abstract Background/Objective: Prognosis remains grim for localized or metastasized pancreatic ductal adenocarcinoma (PDAC) with 5-year survival rates of 3-16%. More than 90% of PDAC cases harbor KRAS mutations. KRASG12C inhibitors recently developed have limited use for PDAC because only 3% of cases express this mutation. We developed a novel pan-RAS inhibitor, ADT-1004 and evaluated antitumor activity in tumor models established from murine or human PDAC cell lines or patient-derived xenografts (PDX). ADT-1004 is an orally bioavailable prodrug of ADT-007, a highly potent and selective pan-RAS inhibitor (doi.org/10.1101/2023.05.17.541233). Methods: Murine PDAC cells harboring the KRASG12D mutation (KPC-Luc or 2838C3-Luc) were orthotopically implanted into the pancreas of C57BL/6J mice. Four PDX PDAC tumors harboring KRAS mutations were implanted orthotopically in NSG mice. To assess potential to overcome RAS inhibitor resistance, parental KRASG12C MIA PaCa-2 PDAC cells and a resistant derivative of MIA PaCa-2 cells were implanted subcutaneously. To assess selectivity, mice were implanted with RASWT BxPC-3 cells SC. Mice were treated orally with ADT-1004 (40mg/kg) 5x/week for 4 weeks. Sotorasib and adagrasib KRASG12C inhibitors were administered at the same dose, route, and schedule as ADT-1004. Results: ADT-007 potently and selectively inhibited the growth of human and mouse PDAC cell lines in vitro. For example, the IC50 value of ADT-007 for KRASG12C MIA PaCa-2 PDAC cells was 2 nM compared to 2500 nM for RASWT BxPC-3 PDAC cells. Growth inhibition by ADT-007 was dependent on activated RAS and associated with reduced GTP-RAS levels and MAPK/AKT signaling. ADT-1004 was well tolerated in mice at doses up to 175 mg/kg bid orally with sustained plasma levels of ADT-007 exceeding growth IC50 values. ADT-1004 displayed robust antitumor activity in mouse tumor models using human- or mouse-derived PDAC cell lines with G12D, G12V, G12C, or G13Q KRAS mutations, causing selective inhibitory effects on ERK phosphorylation in tumors but not in normal tissues. ADT-1004 also inhibited growth of KRASG12C mutant MIA PaCa-2 tumors to a comparable extent as sotorasib and adagrasib. Sotorasib and adagrasib were ineffective against xenografted tumors of resistant cells derived from MIA PaCa-2 cells, while ADT-1004 strongly inhibited tumor growth. Target selectivity of ADT-1004 was confirmed in vivo, as ADT-1004 did not affect the growth of RASWT BxPC-3 tumors. Conclusions: ADT-1004 inhibited tumor growth of KRAS mutant PDAC tumors by blocking activated RAS to disrupt downstream MAPK/AKT signaling. Side-by-side comparisons reveal antitumor efficacy advantages of ADT-1004 over mutant-specific KRAS inhibitors. These results highlight the promise of ADT-1004 for treatment of PDAC and other RAS-driven cancers by addressing the complex genetic landscape of many cancers and limitations from resistance to mutant specific KRAS inhibitions. Citation Format: Dhana Sekhar Reddy Bandi, Ganji P Nagaraju, Jeremy B Foote, Adam B Keeton, Xi Chen, Kristy L Berry, Yulia Y Maxuitenko, Upender Manne, Donald J Buchsbaum, Gary A Piazza, Bassel F El-Rayes. Efficacy advantages of a novel pan-RAS inhibitor, ADT-1004, over mutant- specific KRAS inhibitors for suppressing pancreatic tumor growth in murine models [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C027.

A potent and selective pan-RAS inhibitor, ADT-1004, targeting complex KRAS mutations for pancreatic cancer.

90 Background: Pancreatic ductal adenocarcinoma (PDAC) is a challenging cancer with a 5-year survival rate of under 12%. More than 90% of PDAC cases involve KRAS mutations. KRASG12C inhibitors recently developed have limited use because only 3% of PDAC express this mutation, highlighting the urgent need for pan-RAS inhibitors to address the complex mutation landscape in PDAC while avoiding resistance mechanisms. We synthesized and evaluated a novel pan-RAS inhibitor, ADT-1004, in mouse tumor models transplanted with mouse PDAC cell lines or patient-derived xenografts. ADT-1004 is an orally bioavailable prodrug of ADT-007, a highly potent and selective pan-RAS inhibitor (doi.org/10.1101/2023.05.17.541233). Methods: Human and mouse PDAC cell lines were utilized to evaluate in vitro growth inhibitory potency and selectivity of ADT-007. For in vivo experiments, KPC-Luc (1 × 105) and 2838C3-Luc (1.5 × 105) PDAC cells harboring the KRASG12D mutation were injected into the pancreas of C57BL/6J mice. After one week, the mice were randomly divided into treatment groups (n = 7 per group) and received oral ADT-1004 at a dose of 40mg/kg body weight five times a week for 4 weeks. Tumor burden was assessed weekly by monitoring bioluminescence signals using the IVIS Xenogen imaging system. Four patient-derived xenografts from PDAC patients with KRASG12C, KRASG12D, KRASG12V, KRASG13Q mutations were subcutaneously implanted in NSG mice by a small incision in the right flank. A week later, when the tumors reached a size of 100mm3 mice were randomized (n=7 per group) and treated orally with 40mg/kg of ADT-1004 five times a week for 6 weeks. Body weight and tumor size were measured twice weekly. Results: ADT-007 potently and selectively inhibited the growth of human and mouse PDAC cell lines. For example, the IC50 value pf ADT-007 for KRASG12C MIA PaCA-2 PDAC cells was as low as 2 nM compared to 2500 nM for RASWT BxPC3 PDAC cells. Growth inhibition was dependent on activated RAS and associated with reduced GTP-RAS levels and MAPK/AKT signaling. ADT-1004 was well tolerated in mice at a dose up to 175 mg/kg bid orally with sustained plasma levels of ADT-007 far exceeding growth IC50 values. When administered orally at 40 mg/kg body weight, ADT-1004 displayed robust antitumor activity in mouse tumor models using patient or mouse derived PDAC cell lines with G12D, G12V, G12C, or G13Q KRAS mutations, causing significant inhibitory effects on ERK phosphorylation. Conclusions: ADT-1004 inhibited tumor growth of KRAS mutant PDA tumors by targeting activated RAS to disrupt downstream MAPK/AKT signaling. The results highlight the promise of ADT-1004 as a novel pan-RAS inhibitor and open new strategies for addressing the complex genetic landscape of PDAC and other RAS driven cancers.

A potent and selective pan-RAS inhibitor, ADT-1004, targeting complex KRAS mutations for pancreatic cancer.

e15085 Background: Pancreatic ductal adenocarcinoma (PDAC) is a challenging cancer with a 5-year survival rate of under 12%. More than 90% of PDAC cases involve KRAS mutations. KRASG12C inhibitors recently developed have limited use because only 3% of PDAC express this mutation, highlighting the urgent need for pan-RAS inhibitors to address the complex mutation landscape in PDAC while avoiding resistance mechanisms. We synthesized and evaluated a novel pan-RAS inhibitor, ADT-1004, in mouse tumor models transplanted with mouse PDAC cell lines or patient-derived xenografts. ADT-1004 is an orally bioavailable prodrug of ADT-007, a highly potent and selective pan-RAS inhibitor (doi.org/10.1101/2023.05.17.541233). Methods: Human and mouse PDAC cell lines were utilized to evaluate in vitro growth inhibitory potency and selectivity of ADT-007. For in vivo experiments, KPC-Luc (1 × 105) and 2838C3-Luc (1.5 × 105) PDAC cells harboring the KRASG12D mutation were injected into the pancreas of C57BL/6J mice. After one week, the mice were randomly divided into treatment groups (n = 7 per group) and received oral ADT-1004 at a dose of 40mg/kg body weight five times a week for 4 weeks. Tumor burden was assessed weekly by monitoring bioluminescence signals using the IVIS Xenogen imaging system. Four patient-derived xenografts from PDAC patients with KRASG12C, KRASG12D, KRASG12V, KRASG13Q mutations were subcutaneously implanted in NSG mice by a small incision in the right flank. A week later, when the tumors reached a size of 100mm3 mice were randomized (n = 7 per group) and treated orally with 40mg/kg of ADT-1004 five times a week for 6 weeks. Body weight and tumor size were measured twice weekly. Results: ADT-007 potently and selectively inhibited the growth of human and mouse PDAC cell lines. For example, the IC50 value of ADT-007 for KRASG12C MIA PaCA-2 PDAC cells was as low as 2 nM compared to 2500 nM for RASWT BxPC3 PDAC cells. Growth inhibition was dependent on activated RAS and associated with reduced GTP-RAS levels and MAPK/AKT signaling. ADT-1004 was well tolerated in mice at a dose up to 175 mg/kg bid orally with sustained plasma levels of ADT-007 far exceeding growth IC50 values. When administered orally at 40 mg/kg body weight, ADT-1004 displayed robust antitumor activity in mouse tumor models using patient or mouse derived PDAC cell lines with G12D, G12V, G12C, or G13Q KRAS mutations, causing significant inhibitory effects on ERK phosphorylation. Conclusions: ADT-1004 inhibited tumor growth of KRAS mutant PDA tumors by targeting activated RAS to disrupt downstream MAPK/AKT signaling. The results highlight the promise of ADT-1004 as a novel pan-RAS inhibitor and open new strategies for addressing the complex genetic landscape of PDAC and other RAS driven cancers.

Transdermal Delivery of Pramipexole Using Microneedle Technology for the Potential Treatment of Parkinson's Disease.

Parkinson's disease (PD) is a debilitating neurodegenerative disease primarily impacting neurons responsible for dopamine production within the brain. Pramipexole (PRA) is a dopamine agonist that is currently available in tablet form. However, individuals with PD commonly encounter difficulties with swallowing and gastrointestinal motility, making oral formulations less preferable. Microneedle (MN) patches represent innovative transdermal drug delivery devices capable of enhancing skin permeability through the creation of microconduits on the surface of the skin. MNs effectively reduce the barrier function of skin and facilitate the permeation of drugs. The work described here focuses on the development of polymeric MN systems designed to enhance the transdermal delivery of PRA. PRA was formulated into both dissolving MNs (DMNs) and directly compressed tablets (DCTs) to be used in conjunction with hydrogel-forming MNs (HFMNs). In vivo investigations using a Sprague-Dawley rat model examined, for the first time, if it was beneficial to prolong the application of DMNs and HFMNs beyond 24 h. Half of the patches in the MN cohorts were left in place for 24 h, whereas the other half remained in place for 5 days. Throughout the entire 5 day study, PRA plasma levels were monitored for all cohorts. This study confirmed the successful delivery of PRA from DMNs (Cmax = 511.00 ± 277.24 ng/mL, Tmax = 4 h) and HFMNs (Cmax = 328.30 ± 98.04 ng/mL, Tmax = 24 h). Notably, both types of MNs achieved sustained PRA plasma levels over a 5 day period. In contrast, following oral administration, PRA remained detectable in plasma for only 48 h, achieving a Cmax of 159.32 ± 113.43 ng/mL at 2 h. The HFMN that remained in place for 5 days demonstrated the most promising performance among all investigated formulations. Although in the early stages of development, the findings reported here offer a hopeful alternative to orally administered PRA. The sustained plasma profile observed here has the potential to reduce the frequency of PRA administration, potentially enhancing patient compliance and ultimately improving their quality of life. This work provides substantial evidence advocating the development of polymeric MN-mediated drug delivery systems to include sustained plasma levels of hydrophilic pharmaceuticals.

Age and Sex in the Development of Hepatic Encephalopathy: Role of Alcohol.

Hepatic encephalopathy (HE) is a neurological condition linked to liver failure. Acute HE (Type A) occurs with acute liver failure, while chronic HE (Type C) is tied to cirrhosis and portal hypertension. HE treatments lag due to gaps in understanding its development by gender and age. We studied how sex and age impact HE and its severity with combined liver toxins. Our findings indicate that drug-induced (thioacetamide, TAA) brain edema was more severe in aged males than in young males or young/aged female rats. However, adding alcohol (ethanol, EtOH) worsens TAA's brain edema in both young and aged females, with females experiencing a more severe effect than males. These patterns also apply to Type A HE induced by azoxymethane (AZO) in mice. Similarly, TAA-induced behavioral deficits in Type C HE were milder in young and aged females than in males. Conversely, EtOH and TAA in young/aged males led to severe brain edema and fatality without noticeable behavioral changes. TAA metabolism was slower in aged males than in young or middle-aged rats. When TAA-treated aged male rats received EtOH, there was a slow and sustained plasma level of thioacetamide sulfoxide (TASO). This suggests that with EtOH, TAA-induced HE is more severe in aged males. TAA metabolism was similar in young, middle-aged, and aged female rats. However, with EtOH, young and aged females experience more severe drug-induced HE as compared to middle-aged adult rats. These findings strongly suggest that gender and age play a role in the severity of HE development and that the presence of one or more liver toxins may aggravate the severity of the disease progression.

Abstract 5915: ADT-1004: A promising pan-RAS inhibitor for targeting KRAS mutations in pancreatic ductal adenocarcinoma

Abstract Background/Objective: Pancreatic ductal adenocarcinoma (PDAC) is a highly challenging cancer with a dismal 5-year survival rate of under 12%. More than 90% of PDAC cases involve mutations in the GTPase KRAS. Unfortunately, existing drugs targeting the RAS family, like sotorasib, exclusively address the KRAS-G12C mutation, mainly found in NSCLC. In PDAC, most patients are diagnosed at advanced stages with unresectable tumors that exhibit various genetic mutations. Approximately 70% of these cases have KRAS-G12D mutations, often co-occurring with KRAS-G12V, KRAS-G12C, and KRAS-G12R mutations. This highlights the urgent need for innovative treatments that effectively address the complex mutation landscape in PDAC and avoid resistance mechanisms associated with mutant-specific or pan-KRAS inhibitors. Methods: KPC-Luc (1 × 105) and 2838C3-Luc (1.5 × 105) PDAC cells carrying the KRAS-G12D mutation were injected into the pancreas of C57BL/6J mice. After one week, the mice were randomly divided into treatment groups (n = 7 per group) and received oral ADT-1004 at a dose of 40mg/kg body weight five times a week for four weeks. Tumor burden was assessed by bioluminescence signals using the IVIS Xenogen imaging system for patient-derived xenografts from PDAC patients with the KRAS-G12V mutation who were subcutaneously implanted in NSG mice. A week later, mice were randomized (n=7 per group) and treated orally with 40mg/kg of ADT-1004 five times a week for six weeks. Body weight and tumor size were measured twice weekly. Results: ADT-1004, a prodrug of ADT-007 that exhibits potent inhibitory effects on the proliferation of both human and murine RAS mutant PDAC cell lines with single-digit nM IC50 values, compared with µM IC50 in PDAC cells with WT RAS, was well tolerated in mice at a dose up to 175 mg/kg bid orally with sustained plasma levels of ADT-007 that exceeded IC50 values by 50-fold and even higher concentrations in pancreatic tumors. When administered orally at 40mg/kg body weight, ADT-1004 resulted in substantial growth inhibition of the KRAS-G12D and KRAS-G12V tumors, leading to profound tumor regression without any accompanying loss in body weight. ADT-1004 also displayed a significant inhibitory effect on ERK phosphorylation. Notably, this inhibition is effective regardless of the specific RAS mutational codon or isozyme, as it specifically targets activated RAS and disrupts downstream KRAS signaling pathways. Conclusion: These results highlight the promise of ADT-1004 as a potential breakthrough for treating PDAC. This novel pan-RAS inhibitor demonstrates potent inhibition of PDAC growth, irrespective of the specific KRAS mutation. Furthermore, it shows an excellent safety profile, with profound tumor regression and no impact on body weight in animal models. These findings open new possibilities for addressing the complex genetic landscape of PDAC. Citation Format: Dhana Sekhar Reddy Bandi, Purnachandra Nagaraju Ganji, Sujith Sarvesh, Yulia Maxuitenko, Jeremy B Foote, Adam B Keeton, Xi Chen, Donald Buchsbaum, Gary Piazza, Bassel El-Rayes. ADT-1004: A promising pan-RAS inhibitor for targeting KRAS mutations in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5915.

Primaquine and chloroquine nano-sized solid dispersion-loaded dissolving microarray patches for the improved treatment of malaria caused by Plasmodium vivax

Malaria is a global parasitic infection that leads to substantial illness and death. The most commonly-used drugs for treatment of malaria vivax are primaquine and chloroquine, but they have limitations, such as poor adherence due to frequent oral administration and gastrointestinal side effects. To overcome these limitations, we have developed nano-sized solid dispersion-based dissolving microarray patches (MAPs) for the intradermal delivery of these drugs. In vitro testing showed that these systems can deliver to skin and receiver compartment up to ≈60% of the payload for CQ-based dissolving MAPs and a total of ≈42% of drug loading for PQ-based dissolving MAPs. MAPs also displayed acceptable biocompatibility in cell tests. Pharmacokinetic studies in rats showed that dissolving MAPs could deliver sustained plasma levels of both PQ and CQ for over 7 days. Efficacy studies in a murine model for malaria showed that mice treated with PQ-MAPs and CQ-MAPs had reduced parasitaemia by up to 99.2%. This pharmaceutical approach may revolutionise malaria vivax treatment, especially in developing countries where the disease is endemic. The development of these dissolving MAPs may overcome issues associated with current pharmacotherapy and improve patient outcomes.

Tip loaded cyclodextrin-carvedilol complexes microarray patches

Carvedilol, a β-blocker prescribed for chronic heart failure, suffers from poor bioavailability and rapid first pass metabolism when administered orally. Herein, we present the development of tip microarray patches (MAPs) composed of ternary cyclodextrin (CD) complexes of carvedilol for transdermal delivery. The ternary complex with hydroxypropyl γ-cyclodextrin (HPγCD) and poly(vinyl pyrrolidone) (PVP) reduced the crystallinity of carvedilol, as evidenced by DSC, XRD, NMR, and SEM analysis. MAPs were fabricated using a two-step process with the ternary complex as the needle layer. The resulting MAPs were capable of breaching ex vivo neonatal porcine skin to a depth ≈600 μm with minimal impact to needle height. Upon insertion, the needle dissolved within 2 h, leading to the transdermal delivery of carvedilol. The MAPs displayed minimal toxicity and acceptable biocompatibility in cell assays. In rats, MAPs achieved significantly higher AUC levels of carvedilol than oral administration, with a delayed Tmax and sustained plasma levels over several days. These findings suggest that the carvedilol-loaded dissolving MAPs have the potential to revolutionise the treatment of chronic heart failure.

Comparative Pharmacokinetics and Injection Site Histopathology in Nude Mice Treated with Long-acting Buprenorphine Formulations.

Two long-acting formulations of buprenorphine are commercially available as analgesics for rodents. However, these drugs have not yet been studied in nude mice. We sought to investigate whether the manufacturer-recommended or labeled mouse doses of either drug would provide and sustain the purported therapeutic plasma concentration of buprenorphine (1 ng/mL) over 72 h in nude mice and to characterize the injection site histopathology. NU/NU nude and NU/+ heterozygous mice were subcutaneously injected with extended-release buprenorphine polymeric formulation (ER; 1 mg/kg), extendedrelease buprenorphine suspension (XR; 3.25 mg/kg), or saline (2.5 mL/kg). Plasma concentrations of buprenorphine were measured 6, 24, 48, and 72 h after injection. The injection site was examined histologically at 96 h after administration. XR dosing yielded significantly higher plasma buprenorphine concentrations than did ER dosing at every time point in both nude and heterozygous mice. No significant difference in plasma buprenorphine concentrations were detected between nude and heterozygous mice. Both formulations yielded plasma levels of buprenorphine of over 1 ng/mL at 6 h; XR sustained buprenorphine plasma levels above 1 ng/mL for over 48 h, whereas ER sustained this level for over 6 h. Injections sites of both formulations were characterized by a cystic lesion with a fibrous/fibroblastic capsule. ER induced more inflammatory infiltrates than did XR. This study indicates that while both XR and ER are suitable for use in nude mice, XR has a longer duration of likely therapeutic plasma levels and induces less subcutaneous inflammation at the injection site.

Nanochannel delivery system for CBD: Sustained low level plasma levels without liver toxicity

Cannabidiol (CBD) is a plant-derived cannabinoid found in marijuana and hemp that has been intensely investigated for its putative anti-inflammatory, anxiolytic and/or analgesic effects. Since all these conditions require long-term treatment, sustained release formulations are being investigated. The nanochannel delivery system (nStrada™), an implant device containing 1 mL of CBD formulation in either sesame oil (SES) or medium-chain triglyceride (MCT) vehicles was used in a 35-day sustained-release pharmacokinetic (PK) experiment in female rats. Rats were surgically implanted with either a polyetheretherketone (PEEK) or titanium (Ti) device on day 0 (D0) and blood was obtained several times a week over 35 days. Following the maximum concentration (Cmax) at D1 of 74.3 ± 26.9 ng/mL and 26.3 ± 16.5 ng/mL in MCT and SES, respectively, the subcutaneous release of CBD from the nStrada™ implants exhibited sustained in vivo release kinetics by D14 until termination of the study on D35. The average steady-state levels were 0.8 ng/mL for CBD delivered in MCT and 0.4 ng/mL for CBD delivered in SES. At necropsy on D35, serum alanine aminotransferase (ALT) was determined, and liver histopathology was evaluated, and neither revealed liver toxicity. Skin histopathology surrounding the implanted devices revealed changes consistent with fibrosis as expected. In vitro release data confirmed consistent delivery of CBD into media containing phosphate buffered saline (PBS) with 5% Labrasol. Overall, these results provide a pre-clinical evaluation of CBD PK following implantation of a constant release device over 35 days and confirm at these CBD plasma levels, there is no concern for liver toxicity.

Novel Treatment Option for Rheumatoid Arthritis through Bone‐Targeted Delivery of Novokinin

ObjectiveRheumatoid arthritis (RA) is an autoimmune inflammatory disorder affecting about 1‐2% of the world population. RA is known to be a major cause of disability which progresses eventually to systemic complexities with high chances of early morbidity. This complex dynamic situation of inflammation is orchestrated by multiple systems in the body, including the Renin‐Angiotensin System (RAS). Angiotensin II (Ang II), a main effector peptide in the RAS, predominantly binds to Angiotensin II Type (I) receptor (AT1R). When it overproduced can result in inflammation, vasoconstriction, and oxidative stress. Ang II also binds to Angiotensin II Type (II) receptor (AT2R), which provides functional antagonism to AT1R activation. Novokinin, a synthetic peptide, promotes beneficial effects through activation of AT2R, and can be considered a potential drug candidate for alternative therapy in RA if its plasma stability and half‐life could be improved. Here, we developed a novel bone‐targeting novokinin Conjugate (Novo Conj), which binds to the bone, utilizes it as a reservoir while protecting it from enzymatic and hydrolytic degradation. We hypothesized that this delivery approach would extend the peptide half‐life and provide sustained plasma levels to elicit anti‐inflammatory activity.MethodHealthy male, Sprague Dawley rats, were induced adjuvant arthritis (AA) by administering 0.2mL of 50mg/mL of Mycobacterium butyricum through the tail base injection. Arthritic rats were divided into three groups (n=5/group) and dosed with saline (Inflamed), novokinin of 400 µg/kg (Novokinin), or an equivalent dose of 400 µg/kg of novokinin (Novo Conj). A group of healthy rats (n=5) received saline and was taken as a healthy control (Control) group. After the emergence of arthritis (i.e., 10‐12 days after adjuvant arthritis induction), animals were dosed with assigned treatment every other day for two weeks. Animals were monitored three times a week for their body weight, paw, and joint diameters. At the end of the experiment, rats were euthanized, plasma/tissues were harvested and analyzed for plasma nitric oxide (NO) and the RAS components by western blot.ResultsThe induction of AA led to a significant reduction in percent body weight gain over time, increased paws and joints swelling, and elevated plasma NO levels. AA brought an imbalance in the RAS enzymatic inflammatory axis indicator, i.e., Angiotensin‐Converting Enzyme (ACE) and ACE2 causing a reduction in ACE2/ACE and AT2R/AT1R ratio. The treatment of arthritic rats by novokinin and Novo Conj restored their body weight gain, reduced paws and joints' swelling, lowered the plasma NO level, and reinstated the imbalanced ratios of enzymes and receptors. These observed anti‐inflammatory effects were significantly higher in the Novo Conj group.ConclusionThis result indicates that the novokinin and its bone‐targeted conjugate shows anti‐inflammatory effects through the RAS. The observed enhanced impacts could be attributed to improved stability and extension of the half‐life of novokinin through its conjugation and binding to the bone. Our novel bone‐targeting delivery of novokinin offers effective alternative therapy for managing RA signs and symptoms and could be further utilized for various RAS disorders.

Current Updates in Transdermal Therapeutic Systems and Their Role in Neurological Disorders.

The transdermal therapeutic system plays an important role in the treatment of neuropathic pain. Transdermal drug delivery is considered an ideal therapeutic approach for the management of chronic neurological disorders in the elderly population. It is a simple to use, non-invasive and painless drug delivery system, which provides sustained therapeutic plasma levels of drug for an extended period. Moreover, it bypasses the first-pass metabolism of the active agent, improves bioavailability and reduces undesired adverse effects, which in turn improves patient compliance. Several transdermal delivery systems are currently under investigation for the treatment of Parkinson's syndrome, Alzheimer's disorders, and Neurological pain. Drug delivery via the transdermal route is proposed as an alternative remedy to overcome the drawbacks associated with the conventional dosage forms for chronic neurological disorders. The management of Alzheimer's disease via transdermal drug administration exhibits the greatest therapeutic improvements in the treatment of cognition and global functioning among neuropathic patients. Technological breakthroughs in transdermal drug administration such as the microreservior system, microneedles, metered-dose transdermal spray (MDTS), needle-free injections, and ultrasound-based transdermal therapeutic systems have been successfully used to treat neurological disorders. For example, microneedle (MN) is a highly efficient and versatile device due to its distinctive properties. Ultrasounds have been very popular for the delivery of bioactive agents across the skin barrier. This review focuses on the recent advances of various technologies employed in the transdermal therapeutic systems and their applications on neurological disorders for achieving therapeutic outcomes on patients.

Pharmacokinetics of a cytosine arabinoside subcutaneous protocol in dogs with meningoencephalomyelitis of unknown aetiology.

Cytosine arabinoside (CA) is a commonly used treatment for dogs with meningoencephalomyelitis of unknown aetiology (MUE) with various proposed protocols, many requiring 24hours (h) of hospitalization or two visits within 24h. This is a unidirectional study evaluating the pharmacokinetics of a CA subcutaneous (SC) protocol and a standard constant rate infusion (CRI) protocol in 8 dogs with MUE. Dogs received the CRI (200mg/m2 IV over 24h), followed by a SC protocol (50mg/m2 every 2h for 4 treatments) four weeks later. Plasma CA concentrations were measured by high-pressure liquid chromatography-tandem mass spectrometry (HPLC-MS). Median peak CA concentration for the SC protocol (3.40µg/ml, range 1.60-9.70µg/ml) was significantly higher than the CRI (1.09µg/ml, range 0.77-1.67µg/ml; p=.02). Median concentration at 1h and 8h following initiation of treatment was significantly higher for the SC protocol (CA1 2.28µg/ml, range 0.97-2.67; CA8 1.83µg/ml, range 0.77-2.84) compared to the CRI (CA1 0.01µg/ml, range 0-0.45; CA8 0.74µg/ml, range 0.67-1.11; p=.01). While the PK properties of CA when administered as a CRI has been previously investigated, this study demonstrated that CA when administered via repeated 50mg/m2 injections every 2h over an 8-h period, provided sustained plasma levels above its therapeutic target and for a significantly longer duration of time than did a standard CRI protocol.

Monounsaturated Fatty Acids in Obesity-Related Inflammation.

Obesity is an important aspect of the metabolic syndrome and is often associated with chronic inflammation. In this context, inflammation of organs participating in energy homeostasis (such as liver, adipose tissue, muscle and pancreas) leads to the recruitment and activation of macrophages, which secrete pro-inflammatory cytokines. Interleukin-1β secretion, sustained C-reactive protein plasma levels and activation of the NLRP3 inflammasome characterize this inflammation. The Stearoyl-CoA desaturase-1 (SCD1) enzyme is a central regulator of lipid metabolism and fat storage. This enzyme catalyzes the generation of monounsaturated fatty acids (MUFAs)—major components of triglycerides stored in lipid droplets—from saturated fatty acid (SFA) substrates. In this review, we describe the molecular effects of specific classes of fatty acids (saturated and unsaturated) to better understand the impact of different diets (Western versus Mediterranean) on inflammation in a metabolic context. Given the beneficial effects of a MUFA-rich Mediterranean diet, we also present the most recent data on the role of SCD1 activity in the modulation of SFA-induced chronic inflammation.

Administration of Cells Engineered to Secrete Fviii-mcoET3 in Prenatal Sheep Recipients Results in Sustained Curative Fviii Plasma Levels for 3 Years after Birth, without Immune or Toxicity-Related Adverse Events

The treatment of hemophilia A (HA) patients by prenatal transplantation (PNT) is a feasible, yet underestimated and unexplored clinical approach. The procedure, similar to that of an amniocentesis, poses minimal risk to both the fetus and the mother. Herein, we report on the PNT of sheep fetuses (n=23) with human placental cells (PLC) transduced with a lentiviral vector encoding a bioengineered high-expression fVIII transgene (mcoET3), at a dose of 107-108/kg at 60-64 gestational days, which corresponds to 16-18 gestational weeks in humans. The cells secreted 5.1-9.7IU-fVIII/106 cells/24h, with a vector copy number of 0.35-0.99 per diploid genome equivalent. 9 animals were lost to natural causes unrelated to the treatment or the procedure, or were euthanized for tissue histopathology. Fourteen animals were available for long-term evaluation. Animals followed up over a 1-year (n=14), 2-year (n=9), and 3-year (n=6) period had increased mean plasma fVIII activity levels of 62.1%, 45.6%, and 50.98% respectively, demonstrating that despite the rapid growth of the animals from approximately 0.1kg at the time of PNT to an average of 80kg by year 3, the fVIII produced by the transplanted cells was sufficient to maintain steady levels throughout the duration of the study. We also examined whether PNT-treated animals developed liver inflammation and/or mounted an immune response to the transplanted cells or the fVIII produced by the mcoET3 transgene. At all-time points post-PNT, hematological parameters and liver enzymes (AST, ALT, and alkaline phosphatase) were normal, demonstrating the absence of any liver toxicity. To determine if PNT-treated animals developed a humoral response to mcoET3, an ELISA was performed at 3-6 and 10-16 months postnatally and demonstrated that PNT-treated animals were devoid of anti-mcoET3 IgG. To establish whether these animals had developed memory T cell responses to mcoET3, ELISpot assays for IFN-g (Th1) and IL-4 (Th2) were performed at 3 different time points. No mcoET3-specific Th1 or Th2 cells were ever detected in any of the PNT recipients. To determine if the PNT recipients developed an immune response to the transplanted PLC, we performed one-way mixed lymphocyte reactions (MLR) against the transplanted PLC, and used a screening panel-reactive antibody test (PRA) to identify the development of anti-HLA antibodies specific for the HLA phenotype of the transplanted PLC. MLR demonstrated robust reactivity towards third-party human lymphocytes but not to the transplanted PLC. In addition, no PLC specific anti-HLA antibodies were found, however 2 of the treated animals had detectable levels of xenogeneic antibodies, towards other HLA phenotypes. RTqPCR analysis demonstrated engraftment of transplanted PLC in all major organs and histopathologic examination showed no evidence of any lentiviral-related or procedural toxicity in any tissue examined. In conclusion, PNT of fetal sheep recipients resulted in sustained high fVIII plasma levels for more than 3 years after birth, with no evidence of therapy-related toxicity, nor the development of fVIII inhibitors. Thus, these studies attest to the feasibility, immunologic advantage, and safety of treating HA prior to birth. Disclosures Doering: Kilpatrick, Townsend & Stockton: Consultancy; Expression Therapeutics, LLC: Current equity holder in private company, Patents & Royalties, Research Funding.

Characteristics of Analgesic Patch Formulations.

Topical and transdermal formulations are a common means of pharmaceutical drug delivery. If a drug is able to penetrate transcutaneously, the skin is an ideal site for the delivery of medications for both local (topical) and systemic (transdermal) effects. The administration of analgesics through the skin poses several potential advantages to those administered orally including compliance, the ability to deliver a drug to a peripheral target site and more stable and sustained plasma levels. One method of drug delivery is with the use of patch formulations – also known as patch systems. Typically, transdermal patches deliver medications intended to reach the systemic circulation, whereas topical patches are designed to keep medication localized for targeted delivery in proximity to the application site. There are a variety of technologies and materials utilized in patches, as well as penetration and formulation enhancers that ultimately affect the performance, efficacy and safety of the patch system. The degree of adherence to the skin is also of critical importance in drug delivery. Patches that lift up or fall off before the prescribed time period may represent a therapeutic failure and must be replaced, increasing patch utilization and cost to the healthcare system or to the patient. The added risk from accidental exposure makes poor patch adhesion a safety issue as well. A variety of analgesics are currently available as patch formulations including local anesthetics, capsaicin, nonsteroidal anti-inflammatory drugs and opioids. This review will highlight each of those patch delivery systems and introduce newer patch technologies that lend towards improved adhesion and compliance. Understanding the designs, limitations and benefits of patch systems will allow clinicians to select between these therapies when appropriate for their patients.

Pharmacodynamic, pharmacokinetic and physical characterization of cilnidipine loaded solid lipid nanoparticles for oral delivery optimized using the principles of design of experiments

Cilnidipine (CND), an anti-hypertensive drug, is known to have low oral bioavailability due to its poor aqueous solubility, low dissolution rate and high gut wall metabolism. In the present study, CND loaded compritol based nanoparticles (CND-CMP-NPs) were prepared by emulsification-solvent evaporation method applying the concepts of design of experiments. Critical factors affecting particle size and loading efficiency (LE%) were assessed by hybrid design approach, comprising of Mini Run Resolution IV design followed by Box–Behnken design. Particle size, PDI, zeta potential and LE% of optimized formulations of CND-CMP-NPs were 207.1 ± 2.9 nm, 0.27 ± 0.1, −22.2 ± 1.9 mV and 15.9 ± 1.3% respectively. No significant changes were observed in physical stability of NPs when stored at 25 °C/60% RH over a period of three months. Pharmacokinetic studies revealed that Fabs of CND-CMP-NPs (0.66) was significantly higher than the free CND (0.27). The Cmax and AUC0–∞ of CND-CMP-NPs (572.4 ± 25.3 ng/mL and 5588.6 ± 229.5 ng/mL × h) were significantly higher (Pcal < 0.0001) as compared to free CND (363.6 ± 23.5 ng/mL and 2316.1 ± 163.6 ng/mL × h). MRT of CND-CMP-NPs (9.8 ± 0.9 h) was significantly higher (Pcal < 0.0001) as compared to free CND (5.7 ± 0.5 h). Pharmacodynamic studies showed a maximum of 38% decrease in systolic blood pressure with more than 20% drop in systolic blood pressure sustained for a total duration of 64 h in the case of CND-CMP-NPs as compared to free CND. CND-CMP-NPs not only provide higher and sustained plasma levels of CND but also higher and sustained antihypertensive therapy as compared to free CND.

Advances in Hereditary Angioedema: The Prevention of Angioedema Attacks With Subcutaneous C1-Inhibitor Replacement Therapy.

Hereditary angioedema (HAE) is a debilitating condition caused by a functional C1-inhibitor (C1-INH) deficiency and characterized clinically by episodes of subcutaneous or submucosal swelling. C1-INH replacement is highly effective for preventing HAE attacks and can improve health-related quality of life. Once available only for intravenous use, C1-INH is now available as a subcutaneous formulation for self-administration, shown to provide sustained plasma levels of C1-INH and reducing the monthly median HAE attack rate by 95% versus placebo in the phase 3 COMPACT study. Subcutaneously administered C1-INH satisfies multiple unmet needs in the management of patients with HAE.

Prevention and Treatment of Rheumatoid Arthritis Using Bone‐Targeted Angiotensin Peptide in Rats

IntroductionThe precise etiology of Rheumatoid Arthritis (RA) remains uncertain; however, it has been shown that inflammation is responsible for activation of the renin–angiotensin system (RAS) which has been implicated in the pathogenesis and complications of RA. The main effectors of the RAS are Ang II and Ang 1‐7 which produced by Ang converting enzyme (ACE) and ACE2, respectively. Ang II is implicated in the up‐regulation of pro‐inflammatory cytokines through AT1R and contributed to the pathogenesis of RA. On the other hand, Ang 1‐7, counteract the inflammatory effects of Ang II by binding to Mas receptor and exerting anti‐inflammatory effects in experimental models of arthritis in rodent. Biological activity of Ang 1‐7 is hampered by its short half‐life due to rapid degradation by peptidases. We developed a novel bone‐seeking Ang 1‐7 conjugate (Ang Conj) and hypothesized that this novel approach will prolong half‐life and provide sustained plasma level to impose anti‐inflammatory activity. Since joint bone is the most common tissue impacted by RA, the rationale of this proposal was that, targeting of the bone with Ang Conj., as an anti‐inflammatory agent, could effectively control the signs and symptoms of arthritis.MethodsOn day one, for induction of adjuvant arthritis (AA), male Sprague Dawley rats were injected at the tail base with 0.2 mL of 50 mg/mL Mycobacterium butyricum. Arthritic animals were divided into 4 groups and treated with saline, Ang II, Ang 1‐7 and Ang Conj. A group of healthy rats received vehicle as control group. Preventive and treatment groups subcutaneously received 200 μg/kg equitant dose daily from day one for 3 weeks or after emergence of arthritis for 1 week, respectively. Animals were monitored daily for their body weight, paw and joint diameters. Animals were then euthanized, plasma/tissues were harvested and analyzed for plasma nitric oxide (NO), and the RAS components.ResultsOur results were in concert with previous reports concerning effects of inflammation on the RAS. AA presented itself by significant reduction in percent body weight gain, increased in paws, joints swelling and NO level, and reduced ACE2/ACE ratio. Administration of Ang 1‐7 or Ang Conj restored body weight gain, diminished the swelling of paws and joints and reduce plasma NO level in both treatment and preventive regimen. Consequently, the reduced ACE2/ACE balance was also restored by Ang 1‐7 and Ang Conj treatment.ConclusionThis result indicates that the prolongation of biological half‐life of Ang 1‐7 through injection of Ang Conj. exerts its anti‐inflammatory action by restoration of ACE2/ACE ratio which can augment the RAS major anti‐inflammatory component i.e. Ang 1‐7. This approach offers an effective strategy and an alternative option for management of RA patients and suggests a cardioprotective potential for this conjugate in management of inflammatory disease conditions such as RA.Support or Funding InformationStartup fund from College of Pharmacy, Idaho State UniversityPlasma nitric oxide levels in control and arthritic rats treated with Ang1‐7 or Ang1‐7 Conj.Figure 1Cardiac ACE2/ACE ratio and Mas receptor expression after treatment of control and arthritic rats with Ang 1‐7 or Ang Conj.Figure 2