Injectable testosterone PLGA microsphere with different characteristics: effect of preparation method (paddle mixing versus microfluidic device).

The purpose of this study was to compare the characteristics of testosterone polylactic-co-glycolic (PLGA) microspheres prepared by a paddle mixer or microfluidics device. The comparison was conducted by not only in vitro evaluation but also in vivo evaluation which has not been reported up to date. We discovered that, among the steps in microsphere preparation, the solvent removal process strongly impacted drug content, particle size and surface morphology. Spectroscopic measurements suggested that molecular interactions and crystallinity of the drug incorporated in the microspheres differed. For the drug release profile, although both mixer- and microfluidics-prepared samples showed similar sustained release of the incorporated drug for approximately one month in vitro, they exhibited different plasma concentration profiles in vivo. Together, our findings show that the preparation process, especially the solvent removal process, may affect the physicochemical characteristics of testosterone PLGA microspheres, leading to different in vivo performance.

Polymer Characteristics for Drug Layering on Particles Using a Novel Melt Granulation Technology, MALCORE®.

MALCORE®, a novel manufacturing technology for drug-containing particles (DCPs), relies on the melt granulation method to produce spherical particles with high drug content. The crucial aspect of particle preparation through MALCORE® involves utilizing polymers that dissolve in the melt component, thereby enhancing viscosity upon heating. However, only aminoalkyl methacrylate copolymer E (AMCE) has been previously utilized. Therefore, this study aims to discover other polymers and comprehend the essential properties these polymers need to possess. The results showed that polyvinylpyrrolidone (PVP) was soluble in the stearic acid (SA) melt component. FTIR examination revealed no interaction between SA and polymer. The phase diagram was used to analyze the state of the SA and polymer mixture during heating. It revealed the mixing ratio and temperature range where the mixture remained in a liquid state. The viscosity of the mixture depended on the quantity and molecular weight of the polymer dissolved in SA. Furthermore, the DCPs prepared using PVP via MALCORE® exhibited similar pharmaceutical properties to those prepared with AMCE. In conclusion, understanding the properties required for polymers in the melt granulation process of MALCORE® allows for the optimization of manufacturing conditions, such as temperature and mixing ratios, for efficient and consistent drug layering.

Prognostic nutritional index after introduction of atezolizumab with bevacizumab predicts prognosis in advanced hepatocellular carcinoma: A multicenter study.

INTRODUCTION: Atezolizumab plus bevacizumab (Atez/Bev) is the preferred treatment for advanced hepatocellular carcinoma (HCC). However, biomarkers of therapeutic efficacy have remained unclear. We took a retrospective approach to explore the role of prognostic nutritional index (PNI) for predicting the outcomes of Atez/Bev treatment. METHODS: One hundred twenty-five HCC patients were enlisted; these patients received Atez/Bev treatment and underwent dynamic computerized tomography/magnetic resonance imaging to determine the treatment response on at least one occasion between October 2020 and January 2023, and their PNI before treatment and at the beginning of the second cycle (PNI-2c) was evaluated. RESULTS: During the initial evaluation, 2 (2%), 28 (22%), 70 (56%), and 25 (20%) patients exhibited a complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD), respectively. Patients with non-PD tended to have higher PNI at baseline and PNI-2c than those with PD (p = 0.245 and 0.122, respectively), with optimal baseline PNI and PNI-2c cut-off values of 42.6 and 40.4, respectively. PNI at baseline could not be used to predict overall survival (OS) or progression-free survival (PFS). However, PNI-2c predicted OS and PFS (PNI-2c ≥ 40.4 vs. < 40.4: 25.3 vs. 16.2 months, P = 0.008 for OS; 12.7 vs. 8.4 months, P = 0.036 for PFS). A multivariate analysis showed a significant association between PNI-2c and OS. CONCLUSIONS: PNI-2c is a predictor of prognosis in HCC patients treated with Atez/Bev therapy.

Drug Extended-Release System Utilizing Micelle Formation of Highly Water-Soluble Drugs and a Counter Polymer.

The objective of this study is to clarify the mechanism of extending release of highly water-soluble drugs via counter polymer (CP) utilization in poly(ethylene oxide) (PEO)/polyethylene glycol (PEG) matrix tablets. Carbomer, poly(acrylic acid), was used as a CP, which has the opposite charges to the drugs. The in vitro release of several highly water-soluble drugs from PEO/PEG tablet with or without CP were tested, the relationship between the sustained release effect by a CP (SRE) and the physicochemical properties of the drugs was investigated. The results demonstrated that the utilization of CP can extend the release of some highly water-soluble drugs by effectively controlling the drug diffusion through matrices. On the other hand, the effectiveness of CP was different depending on the drugs applied. There were not statistical correlations between SRE and physicochemical properties such as solubility, molecular weight, and charge intensity of the drugs, while a micelle forming property of the drugs played an important role in SRE by CP. It was concluded that CP, Carbomer, having negative charges could effectively interact with opposite charges on the surface of stable drug micelles, which could result in a significant decrease in drug diffusion leading to extended drug release. It is considered that the system utilizing CP is a promising approach to achieve extended release of highly water-soluble drugs with a reasonable tablet size, especially in the case of large drug loading.

Dual role of autotaxin as novel biomarker and therapeutic target in pancreatic neuroendocrine neoplasms.

Pancreatic neuroendocrine neoplasms (panNENs) are rare pancreatic neoplasms, and descriptions of treatment remain limited. Autotaxin (ATX) is a secreted autocrine motility factor involved in the production of lysophosphatidic acid (LPA), a lipid mediator that promotes the progression of various cancers. The aim of this study was to clarify the importance of the ATX-LPA axis in panNENs and to confirm its contribution to panNEN progression using clinical data, cell lines, and a mouse model. Serum ATX level was higher in patients with panNEN than in patients with other pancreatic diseases (chronic pancreatitis, pancreatic ductal adenocarcinoma [PDAC], intraductal papillary mucinous neoplasm, autoimmune pancreatitis) and healthy controls, and 61% of clinical specimens stained strongly for ATX. In a case we encountered, serum ATX level fluctuated with disease progression. An in vitro study showed higher ATX mRNA expression in panNEN cell lines than in PDAC cell lines. Cell proliferation and migration in panNEN cell lines were stimulated via the ATX-LPA axis and suppressed by RNA interference or inhibitors. An in vivo study showed that intraperitoneal injection of GLPG1690, an ATX inhibitor, suppressed tumor progression in a xenograft model. These findings revealed that ATX expression is significantly elevated in panNEN and is related to the progression of panNEN. We showed the potential of ATX as a novel biomarker and therapeutic target.

3D-Printed Fast-Dissolving Oral Dosage Forms via Fused Deposition Modeling Based on Sugar Alcohol and Poly(Vinyl Alcohol)-Preparation, Drug Release Studies and In Vivo Oral Absorption.

Three-dimensional printing technology holds marked promise for the pharmaceutical industry and is now under intense investigation. Most research is aimed at a greater efficiency in printing oral dosage forms using powder bed printing or fused deposition modeling (FDM). Oral dosage forms printed by FDM tend to be hard objects, which reduce the risk of cracking and chipping. However, one challenge in printing oral dosage forms via FDM is achieving rapid drug release, because the materials for FDM are basically thermoplastic polymers with slow drug release properties. In this study, we investigated printing a fast-dissolving oral dosage form by adding sugar alcohol to a poly(vinyl alcohol)-based formulation for FDM. Filaments which contain sugar alcohol were successfully prepared, and objects were printed with them as oral dosage forms by FDM. On drug release testing, a printed oral dosage form in a ring shape which contained 55% maltitol showed a more than 85% drug release in 15 min. In vivo oral absorption of this printed oral dosage form in dogs was comparable to that of a conventional fast-dissolving tablet. Of particular interest, the drug release profile and drug amount of the oral dosage forms can be easily controlled by a change in shape using 3D Computer Aided Design. These characteristics will encourage the prevalence of FDM by the pharmaceutical industry, and contribute to the promotion of personalized medicine.

Sangelose-based gels and films: effects of glycerol and α-cyclodextrin and their pharmaceutical application.

OBJECTIVE: To evaluate the possible application of Sangelose as an alternative to gelatin and carrageenan for the development of film substrates, and to examine the effect of glycerol and α-cyclodextrin (α-CyD) on the viscoelastic properties of Sangelose-based gels and the physical properties of the films. SIGNIFICANCE: Sangelose-based gels/films can serve as a potential viable alternative to gelatin and carrageenan in pharmaceutical applications. METHODS: Glycerol (a plasticizer) and α-CyD (a functional additive) were added to Sangelose, and gels and films were prepared. The gels were evaluated by dynamic viscoelasticity measurements, and the films were evaluated by scanning electron microscopy, Fourier-transform infrared spectroscopy, tensile tests, and contact angle measurements. Soft capsules were prepared using the formulated gels. RESULTS: The strength of the gels was affected when only glycerol was added to Sangelose and α-CyD addition resulted in rigid gels. However, the addition of α-CyD with 10% glycerol weakened the gels. Tensile tests suggested that glycerol addition affected the formability and malleability of the films, while α-CyD addition affected their formability and elongation properties. The addition of 10% glycerol and α-CyD did not affect the flexibility of the films, suggesting that the malleability and strength were impacted. Soft capsules could not be prepared by adding only glycerol or α-CyD to Sangelose. Soft capsules with favorable disintegration behavior were obtained upon adding α-CyD to gels along with 10% glycerol. CONCLUSIONS: Sangelose combined with a suitable amount of glycerol and α-CyD has preferable characteristics for film formation and may have potential applications in the pharmaceutical and health food sectors.

The neutrophil-to-lymphocyte ratio at the start of the second course during atezolizumab plus bevacizumab therapy predicts therapeutic efficacy in patients with advanced hepatocellular carcinoma: A multicenter analysis.

AIM: Atezolizumab plus bevacizumab (Atez/Bev) therapy is expected to have good therapeutic efficacy for patients with advanced hepatocellular carcinoma (HCC). However, the clinical indicators that predict therapeutic efficacy have not been established. We retrospectively investigated whether the neutrophil-to-lymphocyte ratio (NLR) during Atez/Bev therapy could predict therapeutic efficacy. METHOD: In total, 110 patients with HCC were enrolled; they were treated with Atez/Bev therapy and evaluated for their initial response by dynamic CT or MRI at least once between October 2020 and July 2022. RESULTS: Of the 110 patients with HCC at the initial evaluation, two (2%) showed a complete response (CR), 22 (20%) partial response (PR), 62 (56%) stable disease (SD), and 24 (21%) progressive disease (PD). The NLR at the start of the second course (NLR-2c) increased from CR + PR to SD to PD. There was no significant association between the baseline NLR and the initial therapeutic response. Patients with CR + PR had lower NLR-2c values than those with SD + PD (p < 0.001) and the optimal cut-off value of NLR-2c was 1.97. Patients with NLR-2c <1.97 had better overall survival and progression-free survival (PFS) than those with NLR-2c ≥1.97 (p = 0.005 for overall survival; p < 0.001 for PFS). A multivariate analysis showed that female sex, higher PIVKA-II levels at baseline, and higher values of NLR-2c were significantly associated with poorer PFS. CONCLUSIONS: The NLR-2c value predicts the initial therapeutic response and prognosis of patients with HCC treated with Atez/Bev therapy.

Clinical impact of bile-derived exosomal microRNAs as novel diagnostic and prognostic biomarkers for biliary tract cancers.

Sampling of bile juice during endoscopic retrograde cholangiopancreatography (ERCP) has potential benefit of being amenable to the identification of novel biomarkers in liquid biopsy. This study reports the results of a global investigation of exosomal microRNAs (miRNAs) in bile to identify potential biomarkers for biliary tract cancers (BTCs). Eighty-eight bile samples collected during ERCP (45 BTC and 43 noncancer control samples) were enrolled in this study. Eleven BTC samples and nine control samples were assigned as the discovery set. Exosomes in bile and serum samples were collected using a glass membrane column with size-controlled macroporous glass (MPG), and exosomal miRNA expression profiles were evaluated using comprehensive miRNA microarray analysis (3D-Gene). For validation, exosomal miRNA in the bile samples of 34 BTCs and 34 controls were comprehensively evaluated using 3D-Gene. In the discovery set, eight exosomal miRNAs in bile were identified as significant aberrant expression markers, while no miRNA with aberrant expression in serum was identified. In a comparison of the discovery and validation sets, miR-451a and miR-3619-3p were identified as reproducible upregulated markers, and the combination of the two bile miRNAs showed an excellent area under the curve (0.819) value for diagnosing BTCs. In addition, high miR-3619-3p expression in bile reflects poorer prognosis of BTCs (hazard ratio = 2.89). The MPG-extracted exosomal miRNAs in bile aspirated during ERCP provide a convenient new approach for diagnosing biliary diseases. Bile-derived miRNA analysis with miR-451a and miR-3619-3p represents a potentially valuable diagnostic strategy for identifying BTCs as well as a predictive indicator of BTC prognosis.

Intranasal Administration of N-acetyl-L-cysteine Combined with Cell-Penetrating Peptide-Modified Polymer Nanomicelles as a Potential Therapeutic Approach for Amyotrophic Lateral Sclerosis.

Intranasal administration is a promising route for direct drug delivery to the brain; its combination with nanocarriers enhances delivery. We have previously shown that intranasal administration combined with PEG-PCL-Tat (a nanocarrier) efficiently delivers drugs to the brain and exhibits excellent therapeutic efficacy against brain diseases. We aimed to clarify whether intranasal administration combined with PEG-PCL-Tat represents a useful drug delivery system (DDS) for amyotrophic lateral sclerosis (ALS) pharmacotherapy. We used N-acetyl-L-cysteine (NAC) as a model drug with low transferability to the spinal cord and determined the physicochemical properties of NAC/PEG-PCL-Tat. After intranasal administration of NAC/PEG-PCL-Tat, we measured the survival duration of superoxide dismutase-1 G93A mutant transgenic mice (G93A mice), widely used in ALS studies, and quantitatively analyzed the tissue distribution of NAC/PEG-PCL-Tat in ddY mice. The mean particle size and zeta potential of NAC/PEG-PCL-Tat were 294 nm and + 9.29 mV, respectively. Treatment with repeated intranasal administration of NAC/PEG-PCL-Tat considerably prolonged the median survival of G93A mice by 11.5 days compared with that of untreated G93A mice. Moreover, the highest distribution after a single administration of NAC/PEG-PCL-Tat was measured in the spinal cord. These results suggest that intranasal administration combined with PEG-PCL-Tat might represent a useful DDS for ALS therapeutics.

Impact of Properties of Hydrated Silicon Dioxide as Core Material on the Characteristics of Drug-containing Particles Prepared by the 2-step Process Melt Granulation Technology, MALCORE®.

Drug-containing particles (DCPs) are frequently used as cores in the development of solid oral dosage forms. The wet layering technique, which is a typical approach for preparing DCPs, requires the use of solvents and a long manufacturing time. In our previous study, we developed a novel manufacturing technology, MALCORE®, which can solve these problems through melt granulation. However, particle size control methods for DCPs in MALCORE® and the effect of the physical properties of the hydrated silicon dioxide (HSD) used for the core have not been clarified. The aim of this study was to examine the effects of the particle and pore sizes of HSD on the properties of the prepared DCPs. The results showed that the DCPs prepared using MALCORE® could be controlled by the particle size of HSD. The drug-loading efficiency tended to decrease as HSD particle size increased. Additionally, the amount of drug layering in DCPs increased as the pore size of HSD increased, but HSDs with a pore size much larger than the particle size were not able to properly layer the drug. These findings are helpful for applying MALCORE® to a variety of oral drug formulations.

Increased Tropism of Extracellular Vesicles Derived from Palmitic Acid-Treated Hepatocytes to Activated Hepatic Stellate Cells.

Myofibroblast-like activated hepatic stellate cells (aHSCs), which produce collagen, a major cause of liver fibrosis, are specific target cells for antifibrotic treatment. Recently, several reports have indicated that extracellular vesicles (EVs) play important roles in cell-to-cell communication through their tropism for specific cells or organs. Therefore, the present study aimed to identify aHSC-directed EVs by focusing on cell-to-cell interactions in the liver under pathological conditions. EVs were derived from the hepatocyte cell line AML12 treated with or without palmitic acid (PA) and evaluated for their physical properties and uptake by the aHSC cell line LX-2. AML12-derived EVs had a mean particle diameter of 110-130 nm, negative charge, and expressed the exosomal makers CD9 and CD63. PA-treated AML12 cells released larger EVs with higher protein levels than those without PA treatment. The intracellular uptake efficacy of EVs derived from PA-treated AML12 cells into activated LX-2 cells was significantly higher than those without PA treatment. Our study revealed that PA treatment induces hepatocytes to release EVs with aHSC-tropism. These findings may contribute to the development of an EV-based drug delivery system (DDS) for aHSC-targeted therapy and provide new insights into the role of steatotic hepatocyte-derived EVs in physiological or pathophysiological functions.

A New Approach for Characterizing the Thixotropic Properties of Gel Formulations as Sprayable Agents Based on Rheological Analysis.

The present study evaluated the rheological properties of gel formulations composed of the thixotropic peptide amphiphile, palmitoyl-glycine-histidine (Pal-GH), and the thickener, propylene glycol alginate (PGA), to propose a proper approach to design sprayable gel formulations with good spray performance and high retention of a therapeutic agent. The hysteresis loop area (HLA), a conventional index of thixotropy, was determined from the relationship between the shear stress and shear rate of various formulations with different amounts of Pal-GH and PGA. In addition, a new assessment method for characterizing the thixotropy using the initial structure recovery speed was determined based on the time course of the complex modulus (G*) after structural breakdown of the gel formulations. The G* values increased with the increase in the amount of Pal-GH and PGA, indicating that the formulations were not deformable. Additionally, high HLA and high initial structure recovery speed are preferable when selecting a formulation with good spray performance and high retention. As suitable combinations of Pal-GH and PGA could exhibit both high HLA and high initial structure recovery speed, they are promising components for gel formulations to be used as sprayable agents with good spray performance and high retention. The results also suggested that the initial structure recovery speed would reflect the thixotropy for the formulation more appropriately than HLA. Thus, the initial structure recovery speed could be a useful scale for the preparation of sprayable gel formulations.

Nose-to-brain/spinal cord delivery kinetics of liposomes with different surface properties.

The administration of liposomes via nose-to-brain delivery is expected to become a strategy for efficient drug delivery to the central nervous system. Efficient nose-to-brain delivery and the kinetics of drugs administered in this manner depend on the properties of liposomes. However, there is a lack of basic knowledge of which liposomes are suitable for this purpose. Here, a qualitative study of intranasally administered liposomes (positively charged, neutral, and negatively charged, with or without polyethylene glycol [PEG] modification; particle size <100 nm) was performed to elucidate their dynamics in the brain and spinal cord. Additionally, a quantitative investigation was performed to ascertain their distribution in each part of the brain and spinal cord. The effects of liposome surface charge and PEG modification on the kinetics and distribution post intranasal administration were investigated via two experiments. Qualitative evaluation was performed via ex vivo observation after intranasal administration of fluorescently labeled liposomes. Neutral PEG-modified liposomes were distributed throughout the brain and spinal cord 60 min after administration, and the fluorescence intensity increased with time. By contrast, non-PEG-modified neutral liposomes showed particularly strong fluorescence in the olfactory bulb, and the fluorescence was localized in the anterior part of the brain. Positively charged liposomes showed low fluorescence around the lateral part of the brain and lumbar spinal cord 60 min after administration. Low fluorescence was observed in the whole brain and spinal cord, with strong fluorescence being observed in the olfactory bulb after 120 min of administration. Negatively charged liposomes showed no fluorescence at 60 min after administration, but low fluorescence was observed throughout the brain and spinal cord 120 min after administration. We quantified the radioactivity in the brain and spinal cord after intranasal administration of radioisotope-labeled liposomes. Neutral liposomes showed the highest distribution by area under the drug concentration-time curve (AUC60-120) in the brain and spinal cord compared to other liposomes. Compared with negatively charged liposomes, positively charged liposomes had a higher distribution in the olfactory bulb and forebrain, while negatively charged liposomes had a higher distribution in the hindbrain and bulbospinal tract cord. In addition, the distribution of PEG-modified neutral liposomes in the brain and spinal cord was significantly enhanced compared to that of non-PEG-modified neutral liposomes after 90 min of intranasal administration. These results indicate that surface charge and PEG modification strongly affect the efficiency of nose-to-brain delivery kinetics, and that PEG-modified neutral liposomes are excellent carriers for drug delivery to a wide area of the brain and spinal cord.

Testosterone Sustained Release Microspheres for the Treatment of Fecal Incontinence.

The objective of this study was to develop a testosterone sustained release formulation for the treatment of fecal incontinence. To suppress the initial burst release of testosterone, which can lead to systemic toxicity, we incorporated a washing step using an aminoalkyl methacrylate copolymer E solution or propylene glycol solution into a typical o/w emulsion method to prepare polylactic-co-glycolic acid microspheres. We used this method to develop a polylactic-co-glycolic acid microsphere formulation that shows sustained release of testosterone for up to one month. Not only did this formulation show a sustained release profile after administration into the intersphincteric groove in minipigs, it also increased both the anal pressure and mass of the external anal sphincter, while keeping systemic testosterone exposure low. Thus, this formulation successfully affected both the internal and external anal sphincters with a sufficient safety profile, deeming it a promising candidate treatment strategy for fecal incontinence.

Drug delivery to the intestinal lymph by oral formulations.

Oral drug delivery systems (DDS) targeting lymphocytes in intestinal lymphatic vessels, ducts, and nodes are useful for treating diverse diseases. The intestinal lymph harbors numerous lymphocyte subsets, and DDS containing lipids such as triglycerides and fatty acids can deliver drugs to the lymph through the chylomicron pathway. DDS are efficient, thus allowing the administration of reduced drug doses, which mitigate systemic adverse effects. Here we review orally administered lipid formulations comprising oil solutions, suspensions, micro/nanoemulsions, self-micro/nano emulsifying DDS, liposomes, micelles, solid lipid nanoparticles, and nanostructured lipid carriers for targeting drugs to the lymph. We first describe the structures of lymphatic vessels and lymph nodes and the oral absorption of lipids and drugs into the intestinal lymph. We next summarize the effects of the properties and amounts of lipids and drugs delivered into the lymph and lymphocytes, as well as their effects on drug delivery ratios of lymph to blood. Finally, we describe lymphatic DDS containing saquinavir, tacrolimus, and methotrexate, and their potency that reduces drug concentrations in blood, which are associated with systemic adverse effects.

One-step versus two-step distal self-expandable metal stent placement: A multicenter prospective randomized trial.

BACKGROUND AND AIM: Two methods of transpapillary covered self-expandable metal stent (SEMS) placement are used for distal malignant biliary obstruction (MBO): after initial drainage by plastic stent (two-step method) and without previous drainage (one-step method). METHODS: In total, 90 patients with unresectable pancreatic cancer and distal MBO were enrolled in this prospective multicenter randomized study and allocated to one-step (n = 45) and two-step (n = 45) groups. The main outcome was the time to recurrent biliary obstruction (TRBO). Secondary outcomes were the rates of early and late adverse events, survival time, the time required for bilirubin level reduction, and cost-effectiveness. RESULTS: The median TRBO did not differ significantly between the one-step and two-step groups (not available vs 314 days, P = 0.134). SEMS migration occurred significantly more frequently in the two-step group (14.3% vs 0%, P = 0.026). No significant difference was observed between groups in early (7.3% vs 14.3%, P = 0.483) or late (12.2% and 11.9%, P = 1) adverse events other than RBO, survival time (P = 0.104), or the median number of days required to reach a bilirubin level considered to be acceptable for chemotherapy administration (<3 mg/dL; P = 0.881). The total costs of stent placement and reintervention were significantly lower in the one-step SEMS group (3347 vs 5465 US dollars, P < 0.001). CONCLUSIONS: The superiority of TRBO with two-step SEMS placement was not demonstrated. One-step SEMS placement might be a promising method from the viewpoints of cost-effectiveness and less invasiveness (UMIN-CTR clinical trial registration number: UMIN000016010).

Scintigraphic evaluation of the in vivo performance of dry-coated delayed-release tablets in humans.

We characterized the gastrointestinal (GI) transit and drug release characteristics of dry-coated delayed-release tablets under both prandial states in humans using a gamma scintigraphy approach. We also estimated the onset time of drug release from the dry-coated tablets after dissolution of the outer layer in a clinical study, and compared findings with those of in vitro release testing. The dry-coated tablets used in this study were composed of a core containing radiolabeled resin (111-Indium) and a gel forming outer layer made of polyethylene oxide and polyethylene glycol. The dry-coated tablets were administered to human subjects in the fasted and fed state (30 min after ingestion of a standard breakfast radiolabeled with 99m-Technetium). Gastric emptying time, small intestinal transit time, and onset of radioactivity release in the GI tract were estimated from scintigraphic imaging. Release characteristics of the radiolabel from the dry-coated tablets were also assessed in in vitro dissolution testing using a USP apparatus 2 (paddle). Ingestion of food affected the gastric emptying time of the dry-coated tablets but not small intestinal transit. Onset timing of the release of radioactivity from the core of two different formulas of dry-coated tablets was characterized. The onset timing of drug release in the fasted subjects was markedly similar to that in the in vitro dissolution testing at a paddle rate of 200 rpm.

Design of novel tacrolimus formulations with chemically synthesized oils for oral lymphatic delivery.

High consumption of oil formulations has been reported to reduce the blood exposure of drugs like tacrolimus. Consumption of oil formulations has also been shown to inhibit T-cell production of interleukin-2 (IL-2) compared to solid dispersion formulations (SDFs). However, a large amount of oil causes gastrointestinal side effects such as diarrhea and low compliance. Here, we investigated the feasibility of reducing the amount of oil and substitution of chemically synthetized oils for natural oils in these formulations. Reducing the amount of sunflower oil increased blood tacrolimus exposure despite sufficient suppression of IL-2 production. While medium-chain triglyceride (MCT) increased tacrolimus blood exposure, addition of 10% glyceryl monostearate (GMS) to MCT significantly decreased drug blood exposure without requiring a large amount of oil (p < .05). Effects of the contents of GMS in the MCT/GMS formulations, and fatty acid composition in GMS on drug blood exposure were also investigated. The results indicated that both the amount and type of oil were important for maintaining a good balance between a reduction in blood exposure and sufficient IL-2 suppression. The ratio of drug concentration in lymphocytes to that in whole blood after dosing with an oil formulation was significantly higher than that after administration of the SDF (p < .01). These results indicate the feasibility of developing oral oil tacrolimus formulations to reduce systemic side effects and maintain high efficacy for practical use in patients.

Effects of Diurnal Variation and Food on Gastrointestinal Transit of 111In-Labeled Hydrogel Matrix Extended-Release Tablets and 99mTc-Labeled Pellets in Humans.

The aim of this research was to characterize the effect of food ingestion and circadian rhythm on the gastrointestinal transit of 2 dosage forms: a hydrogel matrix extended-release (ER) tablet and pellets with the diameter of 9 mm and 150-200 µm, respectively, in humans. Radiolabeled (111In) hydrogel matrix ER tablet and capsule containing radiolabeled (99mTc) pellets were administered with 240 mL of water under the following dosing conditions: fasted state at 8 AM or 8 PM and fed state at 8 AM or 8 PM. A high-fat and high-calorie meal was ingested in the fed state studies. The gastric emptying times and small intestinal transit times of the 2 dosage forms were monitored using gamma scintigraphy. Meal ingestion prolonged gastric emptying times for both dosage forms but had no significant impact on the small intestinal transit times of them. Administration time tended to affect gastric emptying of the ER tablet but had no significant impact on gastric emptying and small intestinal transit for both dosage forms.