Simultaneous infusion of two incompatible antibiotics: Impact of the choice of infusion device and concomitant simulated fluid volume support on the particulate load and the drug mass flow rates.

Vancomycin and piperacillin/tazobactam are known to be incompatible. The objectives of the present study were to evaluate the impact of their simultaneous infusion on mass flow rates and particulate load and identify preventive strategies. We assessed both static conditions and a reproduction of an infusion line used in a hospital's critical care unit. A high-performance liquid chromatography/UV diode array system and static and dynamic laser diffraction particle counters were used. The mass flow rates were primarily influenced by the choice of the infusion device and the presence of simulated fluid volume support. Drug incompatibility also appeared to affect vancomycin's mass flow rate, and the dynamic particulate load increased during flow rate changes - especially in the infusion set with a large common volume line and no concomitant simulated fluid volume support. Only discontinuation of the piperacillin/tazobactam infusion was associated with a higher particulate load in the infusion set with a large common volume line and no concomitant simulated fluid volume support. A low common volume line and the use of simulated fluid volume support were associated with smaller fluctuations in the mass flow rate. The clinical risk associated with a higher particulate load must now be assessed.

Neuropsychopharmacological profiling of scoparone in mice.

Scoparone (6,7-dimethoxycoumarin) is a simple coumarin from botanical drugs of Artemisia species used in Traditional Chinese Medicine and Génépi liquor. However, its bioavailability to the brain and potential central effects remain unexplored. We profiled the neuropharmacological effects of scoparone upon acute and subchronic intraperitoneal administration (2.5-25 mg/kg) in Swiss mice and determined its brain concentrations and its effects on the endocannabinoid system (ECS) and related lipids using LC-ESI-MS/MS. Scoparone showed no effect in the forced swimming test (FST) but, administered acutely, led to a bell-shaped anxiogenic-like behavior in the elevated plus-maze test and bell-shaped procognitive effects in the passive avoidance test when given subchronically and acutely. Scoparone rapidly but moderately accumulated in the brain (Cmax < 15 min) with an apparent first-order elimination (95% eliminated at 1 h). Acute scoparone administration (5 mg/kg) significantly increased brain arachidonic acid, prostaglandins, and N-acylethanolamines (NAEs) in the FST. Conversely, subchronic scoparone treatment (2.5 mg/kg) decreased NAEs and increased 2-arachidonoylglycerol. Scoparone differentially impacted ECS lipid remodeling in the brain independent of serine hydrolase modulation. Overall, the unexpectedly potent central effects of scoparone observed in mice could have toxicopharmacological implications for humans.

Intravenous Local Anesthetic Compared With Intraperitoneal Local Anesthetic in Laparoscopic Colectomy: A Double-blind Randomized Controlled Trial.

INTRODUCTION: Controlling perioperative pain is essential to improving patient experience and satisfaction following surgery. Traditionally opioids have been frequently utilized for postoperative analgesia. Although they are effective at controlling pain, they are associated with adverse effects, including postoperative nausea, vomiting, ileus, and long-term opioid dependency.Following laparoscopic colectomy, the use of intravenous or intraperitoneal infusions of lidocaine (IVL, IPL) are promising emerging analgesic options. Although both techniques are promising, there have been no direct, prospective randomized comparisons in patients undergoing laparoscopic colon resection. The purpose of this study was to compare IPL with IVL. METHODS: Double-blinded, randomized controlled trial of patients undergoing laparoscopic colonic resection. The 2 groups received equal doses of either IPL or IVL which commenced intra-operatively with a bolus followed by a continuous infusion for 3 days postoperatively. Patients were cared for through a standardized enhanced recovery after surgery program. The primary outcome was total postoperative opioid consumption over the first 3 postoperative days. Patients were followed for 60 days. RESULTS: Fifty-six patients were randomized in a 1:1 fashion to the IVL or IPL groups. Total opioid consumption over the first 3 postoperative days was significantly lower in the IPL group (70.9 mg vs 157.8 mg P < 0.05) and overall opioid consumption during the total length of stay was also significantly lower (80.3 mg vs 187.36 mg P < 0.05. Pain scores were significantly lower at 2 hours postoperatively in the IPL group, however, all other time points were not significant. There were no differences in complications between the 2 groups. CONCLUSION: Perioperative use of IPL results in a significant reduction in opioid consumption following laparoscopic colon surgery when compared to IVL. This suggests that the peritoneal cavity/compartment is a strategic target for local anesthetic administration. Future enhanced recovery after surgery recommendations should consider IPL as an important component of a multimodal pain strategy following colectomy.

Identification of the toxic threshold of 3-hydroxybutyrate-sodium supplementation in septic mice.

BACKGROUND: In septic mice, supplementing parenteral nutrition with 150 mg/day 3-hydroxybutyrate-sodium-salt (3HB-Na) has previously shown to prevent muscle weakness without obvious toxicity. The main objective of this study was to identify the toxic threshold of 3HB-Na supplementation in septic mice, prior to translation of this promising intervention to human use. METHODS: In a centrally-catheterized, antibiotic-treated, fluid-resuscitated, parenterally fed mouse model of prolonged sepsis, we compared with placebo the effects of stepwise escalating doses starting from 150 mg/day 3HB-Na on illness severity and mortality (n = 103). For 5-day survivors, also the impact on ex-vivo-measured muscle force, blood electrolytes, and markers of vital organ inflammation/damage was documented. RESULTS: By doubling the reference dose of 150 mg/day to 300 mg/day 3HB-Na, illness severity scores doubled (p = 0.004) and mortality increased from 30.4 to 87.5 % (p = 0.002). De-escalating this dose to 225 mg still increased mortality (p ≤ 0.03) and reducing the dose to 180 mg/day still increased illness severity (p ≤ 0.04). Doses of 180 mg/day and higher caused more pronounced metabolic alkalosis and hypernatremia (p ≤ 0.04) and increased markers of kidney damage (p ≤ 0.05). Doses of 225 mg/day 3HB-Na and higher caused dehydration of brain and lungs (p ≤ 0.05) and increased markers of hippocampal neuronal damage and inflammation (p ≤ 0.02). Among survivors, 150 mg/day and 180 mg/day increased muscle force compared with placebo (p ≤ 0.05) up to healthy control levels (p ≥ 0.3). CONCLUSIONS: This study indicates that 150 mg/day 3HB-Na supplementation prevented sepsis-induced muscle weakness in mice. However, this dose appeared maximally effective though close to the toxic threshold, possibly in part explained by excessive Na+ intake with 3HB-Na. Although lower doses were not tested and thus might still hold therapeutic potential, the current results point towards a low toxic threshold for the clinical use of ketone salts in human critically ill patients. Whether 3HB-esters are equally effective and less toxic should be investigated.

Propofol rather than Isoflurane Accelerates the Interstitial Fluid Drainage in the Deep Rat Brain.

Objective: Different anesthetics have distinct effects on the interstitial fluid (ISF) drainage in the extracellular space (ECS) of the superficial rat brain, while their effects on ISF drainage in the ECS of the deep rat brain still remain unknown. Herein, we attempt to investigate and compare the effects of propofol and isoflurane on ECS structure and ISF drainage in the caudate-putamen (CPu) and thalamus (Tha) of the deep rat brain. Methods: Adult Sprague-Dawley rats were anesthetized with propofol or isoflurane, respectively. Twenty-four anesthetized rats were randomly divided into the propofol-CPu, isoflurane-CPu, propofol-Tha, and isoflurane-Tha groups. Tracer-based magnetic resonance imaging (MRI) and fluorescent-labeled tracer assay were utilized to quantify ISF drainage in the deep brain. Results: The half-life of ISF in the propofol-CPu and propofol-Tha groups was shorter than that in the isoflurane-CPu and isoflurane-Tha groups, respectively. The ECS volume fraction in the propofol-CPu and propofol-Tha groups was much higher than that in the isoflurane-CPu and isoflurane-Tha groups, respectively. However, the ECS tortuosity in the propofol-CPu and propofol-Tha groups was much smaller than that in isoflurane-CPu and isoflurane-Tha groups, respectively. Conclusions: Our results demonstrate that propofol rather than isoflurane accelerates the ISF drainage in the deep rat brain, which provides novel insights into the selective control of ISF drainage and guides selection of anesthetic agents in different clinical settings, and unravels the mechanism of how general anesthetics function.

Parenteral iron therapy and phosphorus homeostasis: A review.

Phosphorus has an essential role in cellular and extracellular metabolism; maintenance of normal phosphorus homeostasis is critical. Phosphorus homeostasis can be affected by diet and certain medications; some intravenous iron formulations can induce renal phosphate excretion and hypophosphatemia, likely through increasing serum concentrations of intact fibroblast growth factor 23. Case studies provide insights into two types of hypophosphatemia: acute symptomatic and chronic hypophosphatemia, while considering the role of pre-existing conditions and comorbidities, medications, and intravenous iron. This review examines phosphorus homeostasis and hypophosphatemia, with emphasis on effects of iron deficiency and iron replacement using intravenous iron formulations.

A novel treatment of bromelain and acetylcysteine (BromAc) in patients with peritoneal mucinous tumours: A phase I first in man study.

BACKGROUND: Bromelain (Brom) and Acetylcysteine (Ac) have synergistic activity resulting in dissolution of tumour-produced mucin both in vitro and in vivo. The aim of this study was to determine whether treatment of mucinous peritoneal tumour with BromAc can be performed with an acceptable safety profile and to conduct a preliminary assessment of efficacy in a clinical setting. METHODS: Under radiological guidance, a drain was inserted into the tumour mass or intraperitoneally. Each patient could have more than one tumour site treated. Brom 20-60 mg and Ac 1·5-2 g was administered in 5% glucose. At 24 h, the patient was assessed for symptoms including treatment-related adverse events (AEs) and the drain was aspirated. The volume of tumour removed was measured. A repeat dose via the drain was given in most patients. All patients that received at least one dose of BromAc were included in the safety and response analysis. FINDINGS: Between March 2018 and July 2019, 20 patients with mucinous tumours were treated with BromAc. Seventeen (85%) of patients had at least one treatment-emergent AE. The most frequent treatment-related AEs were CRP rise (n = 16, 80%), WCC rise (n = 11, 55%), fever (n = 7, 35%, grade I) and pain (n = 6, 30%, grade II/III). Serious treatment-related AEs accounted for 12·5% of all AEs. There were no anaphylactic reactions. There were no deaths due to treatment-related AEs. An objective response to treatment was seen in 73·2% of treated sites. CONCLUSION: Based on these preliminary results and our preclinical data, injection of BromAc into mucinous tumours had a manageable safety profile. Considerable mucolytic activity was seen by volume of mucin extracted and radiological appearance. These results support further investigation of BromAC for patients with inoperable mucinous tumours and may provide a new and minimally invasive treatment for these patients.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal and appendiceal peritoneal metastases - The Hong Kong experience and literature review.

INTRODUCTION: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is increasingly used to treat peritoneal metastases from appendiceal or colorectal origin. We evaluate our institution's experience and survival outcomes with this procedure, and its efficacy in symptom relief. METHODS: This is a single-centre retrospective observational study on patients with peritoneal metastases (PM) from appendiceal neoplasm or colorectal cancer who underwent CRS/HIPEC in Queen Mary Hospital. Our primary endpoints were overall survival (OS) and morbidity and mortality of this procedure; secondary endpoints included disease-free survival (DFS) and symptom-free survival. RESULTS: Between 2006 and 2018, thirty CRS/HIPEC procedures were performed for 28 patients - 17 (60.7%) had appendiceal PM while 11 (39.9%) had colorectal PM. The median peritoneal cancer index was 20; complete cytoreduction was achieved in 83.3% patients. High-grade morbidity occurred in 13.3% cases. There was no 30-day mortality. Two-year OS were 71.6% and 50% for low-grade appendiceal PM and colorectal PM patients (p = 0.20). Complete cytoreduction improved OS (2-year OS 75.4% vs 20%, p = 0.04). Median DFS was 11.8 months. Median symptom-free duration was 36.8 months; patients with complete cytoreduction were more likely to remain asymptomatic (82.9% at 1 year, vs 60% in incomplete cytoreduction group, p < 0.01). 91.7% low-grade appendiceal PM patients and 58.4% colorectal PM patients remained asymptomatic at post-operative one year (p = 0.31). CONCLUSION: CRS/HIPEC is beneficial to appendiceal PM and selected colorectal PM patients - improving survival and offering prolonged symptom relief, with reasonable morbidity and mortality. Complete cytoreduction is key to realising this benefit.

Parenteral fish oil: An adjuvant pharmacotherapy for coronavirus disease 2019?

The new coronavirus associated with severe acute respiratory syndrome (SARS-CoV-2), surprisingly, does not affect only the lungs. The severe response to SARS-CoV-2 appears to include a "cytokine storm," which indicates a state of hyperinflammation and subsequent dysfunction of multiple organs and tissues in the most severe cases. This could be the reason why populations at the highest risk for death from the SARS-CoV-2 infection-induced disease (coronavirus disease 2019 [COVID-19]) are those suffering from chronic low-grade inflammation, but prone to hyperinflammation. This includes individuals of advanced age and those with obesity, type 2 diabetes, hypertension, and metabolic syndrome. Inflammation resolution is strongly dependent on lipid mediators, the specialized pro-resolution mediators (SPMs). ω-3 polyunsaturated fatty acids (ω-3 PUFAs) are precursors of very potent SPMs, including resolvins, protectins, and maresins. Additionally, they are associated with a less aggressive inflammatory initiation, after competing with ω-6 fatty acids for eicosanoid synthesis. Therefore, it makes sense to consider the use of ω-3 PUFAs for clinical management of COVID-19 patients. ω-3 PUFAs may be given by oral, enteral, or parenteral routes; however, the parenteral route favors faster incorporation into plasma phospholipids, blood cells, and tissues. Here, we discuss these aspects to propose the parenteral infusion of ω-3 PUFAs as adjuvant immunopharmacotherapy for hospitalized patients with COVID-19.

Observations from a peculiar case of volatile substance dependence-A case report.

Volatile substance dependence is a relatively rare form of substance use disorders. It is predominantly noted in the adolescent age group. Higher prevalence is also seen in individuals from the lower socio-economic strata. These agents induce a rapid mood change by altering the levels of central neurotransmitters. Here we present a unique case of volatile substance dependence in a middle aged female with iron deficiency anemia. We managed this with the SSRIs and parenteral iron preparations which led to recovery. This emphasizes the fact that any treatment regimen must address all the factors, co-morbidities and patient characteristics for complete recovery.

DNA damage and health effects in juvenile haddock (Melanogrammus aeglefinus) exposed to PAHs associated with oil-polluted sediment or produced water.

The research objective was to study the presence of DNA damages in haddock exposed to petrogenic or pyrogenic polyaromatic hydrocarbons (PAHs) from different sources: 1) extracts of oil produced water (PW), dominated by 2-ring PAHs; 2) distillation fractions of crude oil (representing oil-based drilling mud), dominated by 3-ring PAHs; 3) heavy pyrogenic PAHs, mixture of 4/5/6-ring PAHs. The biological effect of the different PAH sources was studied by feeding juvenile haddock with low doses of PAHs (0.3-0.7 mg PAH/kg fish/day) for two months, followed by a two-months recovery. In addition to the oral exposure, a group of fish was exposed to 12 single compounds of PAHs (4/5/6-ring) via intraperitoneal injection. The main endpoint was the analysis of hepatic and intestinal DNA adducts. In addition, PAH burden in liver, bile metabolites, gene and protein expression of CYP1A, GST activity, lipid peroxidation, skeletal deformities and histopathology of livers were evaluated. Juvenile haddock responded quickly to both intraperitoneal injection and oral exposure of 4/5/6-ring PAHs. High levels of DNA adducts were detected in livers three days after the dose of the single compound exposure. Fish had also high levels of DNA adducts in liver after being fed with extracts dominated by 2-ring PAHs (a PW exposure scenario) and 3-ring PAHs (simulating an oil exposure scenario). Elevated levels of DNA adducts were observed in the liver of all exposed groups after the 2 months of recovery. High levels of DNA adduct were found also in the intestines of individuals exposed to oil or heavy PAHs, but not in the PW or control groups. This suggests that the intestinal barrier is very important for detoxification of orally exposures of PAHs.

HIPEC in advanced epithelial ovarian cancer: why is there controversy?

PURPOSE OF REVIEW: The randomized OVHIPEC study provided further evidence that adding heated intraperitoneal chemotherapy (HIPEC) to interval cytoreductive surgery significantly improved recurrence-free and overall survival in stage III epithelial ovarian cancer (EOC) patients, who were ineligible for primary cytoreductive surgery due to extensive intraperitoneal disease. Because opinions have been divided as to whether HIPEC is now a new standard of care for advanced EOC, the pros and cons of this approach are examined. A comparison with the ongoing discussion about the role of intraperitoneal chemotherapy is made. RECENT FINDINGS: For both techniques, experience is crucial and a learning curve essential. Compared with intraperitoneal chemotherapy, intraoperative application of HIPEC provides superior distribution through the peritoneal cavity. HIPEC, as given in OVHIPEC, did not significantly increase adverse events, had no negative effect on quality of life and was cost-effective. SUMMARY: Despite the ongoing debate about HIPEC, an important first step in attempting to demonstrate the efficacy of HIPEC in the first-line setting has been made with OVHIPEC. Critics have been of value to optimize future trials with HIPEC in patients with EOC.

Molecular Aspects and Treatment of Iron Deficiency in the Elderly.

Iron deficiency (ID) is the most frequent nutritional deficiency in the whole population worldwide, and the second most common cause of anemia in the elderly. The prevalence of anemia is expecting to rise shortly, because of an ageing population. Even though WHO criteria define anemia as a hemoglobin serum concentration <12 g/dL in women and <13 g/dL in men, several authors propose different and specific cut-off values for the elderly. Anemia in aged subjects impacts health and quality of life, and it is associated with several negative outcomes, such as longer time of hospitalization and a higher risk of disability. Furthermore, it is an independent risk factor of increased morbidity and mortality. Even though iron deficiency anemia is a common disorder in older adults, it should be not considered as a normal ageing consequence, but a sign of underlying dysfunction. Relating to the molecular mechanism in Iron Deficiency Anemia (IDA), hepcidin has a key role in iron homeostasis. It downregulates the iron exporter ferroportin, inhibiting both iron absorption and release. IDA is frequently dependent on blood loss, especially caused by gastrointestinal lesions. Thus, a diagnostic algorithm for IDA should include invasive investigation such as endoscopic procedures. The treatment choice is influenced by the severity of anemia, underlying conditions, comorbidities, and the clinical state of the patient. Correction of anemia and iron supplementation should be associated with the treatment of the causal disease.

Oncologic outcomes and morbidity following heated intraperitoneal chemotherapy at cytoreductive surgery for primary epithelial ovarian cancer: A systematic review and meta-analysis.

OBJECTIVES: Heated intraperitoneal chemotherapy (HIPEC) has not been universally adopted at the time of interval cytoreductive surgery for primary epithelial ovarian cancer (EOC) despite evidence of a 12-month overall survival (OS) benefit in a recent landmark randomized trial. We performed a systematic review and meta-analysis to assess oncologic outcomes and perioperative morbidity following HIPEC among primary EOC patients. METHODS: We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews, from inception to August 2019, for observational and randomized studies of primary EOC patients undergoing HIPEC. We assessed risk of bias using the Institute of Health Economics Quality Appraisal Checklist for single-arm cohort studies, Newcastle-Ottawa Scale for comparative cohort studies, and Cochrane Collaboration's Tool for randomized trials. We qualitatively summarized survival outcomes and calculated the pooled proportion of 30-day grade III-IV morbidity and postoperative death. RESULTS: We identified 35 articles including 2252 primary EOC patients; one study was a randomized trial, and only six studies included a comparator group of surgery alone. The timing, temperature, and chemotherapeutic agents used for HIPEC differed across studies. Reported OS was highly variable (3-year OS range: 46-77%); three comparative cohort studies and the sole randomized trial reported statistically significant survival benefits for HIPEC over surgery alone, while two comparative cohort studies did not. The pooled proportions for grade III-IV morbidity and postoperative death at 30 days were 34% (95% CI 20-52) and 0% (95% CI 0-5) respectively. CONCLUSION: One randomized trial suggests that HIPEC at time of interval cytoreductive surgery should be considered in patients with primary EOC. However, there is significant heterogeneity in literature with respect to an appropriate HIPEC regimen, short- and long-term outcomes. High-quality prospective randomized trials are urgently needed to clarify the role of HIPEC in the first-line treatment of primary EOC.

Evaluating the Potential of Ursolic Acid as Bioproduct for Cutaneous and Visceral Leishmaniasis.

Leishmaniasis affects around 12 million people worldwide and is estimated to cause the ninth-largest disease burden. There are three main forms of the disease, visceral (VL), cutaneous (CL), and mucocutaneous (MCL), leading to more than one million new cases every year and several thousand deaths. Current treatments based on chemically synthesized molecules are far from ideal. In this study, we have tested the in vitro and in vivo efficacy of ursolic acid (UA), a multifunctional triterpenoid with well-known antitumoral, antioxidant, and antimicrobial effects on different Leishmania strains. The in vitro antileishmanial activity against the intracellular forms was six and three-fold higher compared to extracellular forms of L. amazonensis and L. infantum, respectively. UA also showed to be a potent antileishmanial drug against both VL and CL manifestations of the disease in experimental models. UA parenterally administered at 5 mg/kg for seven days significantly reduced the parasite burden in liver and spleen not only in murine acute infection but also in a chronic-infection model against L. infantum. In addition, UA ointment (0.2%) topically administered for four weeks diminished (50%) lesion size progression in a chronic infection model of CL caused by L. amazonensis, which was much greater than the effect of UA formulated as an O/W emulsion. UA played a key role in the immunological response modulating the Th1 response. The exposure of Leishmania-infected macrophages to UA led to a significant different production in the cytokine levels depending on the Leishmania strain causing the infection. In conclusion, UA can be a promising therapy against both CL and VL.

Comparison of Oral and Parenteral Iron Administration on Iron Homeostasis, Oxidative and Immune Status in Anemic Neonatal Pigs.

The present study was to evaluate the consequences of iron status across oral and parenteral iron administrations in prevention of iron deficiency anemia. A total of 24 one-day-old male neonatal piglets were allocated into three groups given non-iron supplementation (NON), intramuscular iron dextran injection (FeDex), and oral administration of ferrous glycine chelate (FeGly), respectively. At day 8, no significant differences in final body weight, average weight gain, and tissue coefficients were observed among three groups (P > 0.05). Both oral FeGly and FeDex injection significantly increased serum iron, ferritin, hemoglobin, and tissue iron deposition (P < 0.05). However, FeDex-injected supplementation resulted in rapidly rising hepcidin levels and hepatic iron deposition (P < 0.05). In addition, compared to parenteral iron supplementation, greater serum IgA level, SOD, and GSH-Px activities, lower expressions of IL-1ß and TNF-α in the liver, and lower expressions of IL-6 and TNF-α in the spleen were found in oral iron piglets (P < 0.05). According to our results, oral administration of ferrous glycine chelate improved iron homeostasis, and oxidative and immune status in anemic neonatal pigs.

Colorectal cancer peritoneal metastases: Biology, treatment and next steps.

The presence of peritoneal metastases in patients with advanced colorectal cancer is associated with poor prognosis but the mechanisms for this are unclear. This review summarises the current knowledge of the pathophysiology, clinical features, prevalence, prognosis, and molecular biology of peritoneal metastases and the risk factors for the development of peritoneal metastases following resection of a primary colorectal tumour. Furthermore, the evidence for treatment strategies are described including cytoreductive surgery, hyperthermic intraperitoneal chemotherapy, early post-operative intraperitoneal chemotherapy, sequential post-operative intraperitoneal chemotherapy and emerging novel strategies. Active areas of research should include the identification of individuals at high risk of peritoneal metastases after curative resection of primary tumour, development of a surveillance program for high-risk patients, optimisation of systematic therapies and further investigation of the use of intraperitoneal chemotherapy.

Preparation of an oil suspension containing ondansetron hydrochloride as a sustained release parenteral formulation.

Ondansetron hydrochloride (ODS) is a selective 5-hydroxytryptamine type 3 antagonist for nausea and emesis prevention in neoplastic patients. To reduce dosing frequency and side effects and improve patient compliance, a sustained release parenteral formulation of ODS was developed. Microparticles of methylcellulose (MC) and ODS were prepared using the spray-drying method and suspended in oils to form oil suspensions. The formulations were evaluated for residual moisture, drug content, size distribution, DSC, XRD, FTIR, SEM, drug release, and pharmacokinetic studies. The effects of polymers and oils on the drug release were evaluated. MC showed the most prominent sustained release effect among various polymers examined with the optimum MC/ODS ratio of 2:1 (w/w). The particle size of the produced microparticles was in the mean diameter of approximately 3 µm. Physicochemical characterization suggested that ODS existed in an amorphous matrix within the microparticles and interacted with MC via hydrogen bonds. Corn oil was selected as the appropriate oil for suspension due to the sustained release of ODS and the appropriate viscosity. The optimized sustained release formulation of ODS was the corn oil suspension of spray-dried microparticles containing MC and ODS (2:1, w/w). It showed an in vitro drug sustained release up to 120 h, while the oil suspension of ODS without any polymer released the drug within 2 h. Following subcutaneous administration in rats, the optimized formulation could prolong the drug release until 72 h with the enhanced bioavailability in comparison with the ODS solution. The oil suspension of spray-dried microparticles might be an efficient approach for prolongation of the drug effect in the management of nausea and emesis. Graphical abstract.