A pilot-randomized, double-blind crossover trial to evaluate the pharmacokinetics of orally administered 25-hydroxyvitamin D3 and vitamin D3 in healthy adults with differing BMI and in adults with intestinal malabsorption.

BACKGROUND: Obese and malabsorptive patients have difficulty increasing serum 25-hydroxyvitamin D [25(OH)D] after taking vitamin D supplementation. Since 25(OH)D is more hydrophilic than vitamin D, we hypothesized that oral 25(OH)D supplementation is more effective in increasing serum 25(OH)D concentrations in these patients. OBJECTIVES: We aimed to investigate the pharmacokinetics of oral 25-hydroxyvitamin D3 [25(OH)D3] and oral vitamin D3 in healthy participants with differing BMI and malabsorptive patients. METHODS: A randomized, double-blind crossover trial was performed in 6 malabsorptive patients and 10 healthy participants who were given 900 µg of either vitamin D3 or 25(OH)D3 orally followed by a pharmacokinetic study (PKS). After ≥28 d from the first dosing, each participant returned to receive the other form of vitamin D and undergo another PKS. For each PKS, serum vitamin D3 and 25(OH)D3 were measured at baseline and at 2, 4, 6, 8, and 12 h and days 1, 2, 3, 7, and 14. Pharmacokinetic parameters were calculated. RESULTS: Data were expressed as means ± SEMs. The PKS of 900 µg vitamin D3 revealed that malabsorptive patients had 64% lower AUC than healthy participants (1177 ± 425 vs. 3258 ± 496 ng · h/mL; P < 0.05). AUCs of 900 µg 25(OH)D3 were not significantly different between the 2 groups (P = 0.540). The 10 healthy participants were ranked by BMI and categorized into higher/lower BMI groups (5/group). The PKS of 900 µg vitamin D3 showed that the higher BMI group had 53% lower AUC than the lower BMI group (2089 ± 490 vs. 4427 ± 313 ng · h/mL; P < 0.05), whereas AUCs of 900 µg 25(OH)D3 were not significantly different between the 2 groups (P = 0.500). CONCLUSIONS: Oral 25(OH)D3 may be a good choice for managing vitamin D deficiency in malabsorption and obesity. This trial was registered at clinicaltrials.gov as (NCT03401541.

Effect of 1-year oral cholecalciferol on a metabolic profile and blood pressure in poor-controlled type 2 diabetes mellitus: an open-label randomized controlled pilot study.

PURPOSE: Hypovitaminosis D has been associated with many cardio-metabolic disorders, although their pathogenetic link still remains unclear. Our aim was to evaluate whether 1-year vitamin D (D) supplementation could improve glycemic control, lipid profile, systolic (SBP) and diastolic (DBP) blood pressure levels and body composition. METHODS: In an open-label randomized-controlled pilot study, thirty poor-controlled (HbA1c > 59 mmol/mol) type 2 diabetic patients (age 71.5 ± 3.2 years, M/F 21/9, BMI 29.8 ± 3.6 kg/m2) with hypovitaminosis D (25OHD 22.0 ± 11.3 nmol/l) were randomized to cholecalciferol supplementation (500 UI/kg p.o. weekly, + D) or observation (- D) for one year. Changes in parameters of glucose, lipid and blood pressure control at 3, 6, 9 and 12 months vs. baseline were assessed. RESULTS: One-year D supplementation restored D status and had a beneficial effect on fasting glucose (FG, mean percentage changes ± SD, - 1.8% ± 23.1 vs. + 18.8% ± 30.0), glycosylated haemoglobin (HbA1c, - 13.7% ± 14.5 vs. - 4.2% ± 14.1), SBP (- 13.4% ± 8.5 vs. - 2.4% ± 12.6) and HDL-cholesterol levels (- 2.1% ± 14.0 vs. - 10.9% ± 12.9; p < 0.05 for all comparisons) in + D vs. - D patients, respectively. In the former, a reduction in HBA1c, SBP and DBP levels, BMI, fat mass index (FMI) and ratio (FMR) was observed after 1 year (p < 0.05 for all comparisons vs. baseline). We noticed a relationship between 1-year mean percentage changes of serum 25OHD and SBP levels (R = - 0.36, p < 0.05). CONCLUSION: One-year cholecalciferol supplementation, able to restore D status, significantly improves FG, HbA1c, SBP and HDL-cholesterol levels in patients with poor-controlled type 2 diabetes mellitus and D deficiency.

Flash Fabrication of Orally Targeted Nanocomplexes for Improved Transport of Salmon Calcitonin across the Intestine.

Salmon calcitonin (sCT) is a potent calcium-regulating peptide hormone and widely applied for the treatment of some bone diseases clinically. However, the therapeutic usefulness of sCT is hindered by the frequent injection required, owing to its short plasma half-life and therapeutic need for a high dose. Oral delivery is a popular modality of administration for patients because of its convenience to self-administration and high patient compliance, while orally administered sCT remains a great challenge currently due to the existence of multiple barriers in the gastrointestinal (GI) tract. Here, we introduced an orally targeted delivery system to increase the transport of sCT across the intestine through both the paracellular permeation route and the bile acid pathway. In this system, sCT-based glycol chitosan-taurocholic acid conjugate (GC-T)/dextran sulfate (DS) ternary nanocomplexes (NC-T) were produced by a flash nanocomplexation (FNC) process in a kinetically controlled mode. The optimized NC-T exhibited well-controlled properties with a uniform and sub-60 nm hydrodynamic diameter, high batch-to-batch reproducibility, good physical or chemical stability, as well as sustained drug release behaviors. The studies revealed that NC-T could effectively improve the intestinal uptake and permeability, owing to its surface functionalization with the taurocholic acid ligand. In the rat model, orally administered NC-T showed an obvious hypocalcemia effect and a relative oral bioavailability of 10.9%. An in vivo assay also demonstrated that NC-T induced no observable side effect after long-term oral administration. As a result, the orally targeted nanocomplex might be a promising candidate for improving the oral transport of therapeutic peptides.

Pharmacokinetic profile analyses for inhaled drugs in humans using the lung delivery and disposition model.

The kinetic clarification of lung disposition for inhaled drugs in humans via pharmacokinetic (PK) modeling aids in their development and regulation for systemic and local delivery, but remains challenging due to its multiplex nature. This study exercised our lung delivery and disposition kinetic model to derive the kinetic descriptors for the lung disposition of four drugs [calcitonin, tobramycin, ciprofloxacin and fluticasone propionate (FP)] inhaled via different inhalers from the published PK profile data. With the drug dose delivered to the lung (DTL) estimated from the corresponding γ-scintigraphy or in vivo predictive cascade impactor data, the model-based curve-fitting and statistical moment analyses derived the rate constants of lung absorption (ka ) and non-absorptive disposition (knad ). The ka values differed substantially between the drugs (0.05-1.00 h-1 ), but conformed to the lung partition-based membrane diffusion except for FP, and were inhaler/delivery/deposition-independent. The knad values also varied widely (0.03-2.32 h-1 ), yet appeared to be explained by the presence or absence of non-absorptive disposition in the lung via mucociliary clearance, local tissue degradation, binding/sequestration and/or phagocytosis, and to be sensitive to differences in lung deposition. For FP, its ka value of 0.2 h-1 was unusually low, suggesting solubility/dissolution-limited slow lung absorption, but was comparable between two inhaler products. Thus, the difference in the PK profile was attributed to differences in the DTL and the knad value, the latter likely originating from different aerosol sizes and regional deposition in the lung. Overall, this empirical, rather simpler model-based analysis provided a quantitative kinetic understanding of lung absorption and non-absorptive disposition for four inhaled drugs from PK profiles in humans.

Pharmacokinetics of a New Pharmaceutical Form of Vitamin D3 100,000 IU in Soft Capsule.

Vitamin D deficiency is frequent in the general population and both subjects and health professionals could benefit from a broader range of vitamin D3 formulations. We conducted a single-dose, open-label, parallel-group, randomized bioequivalence study to compare a single dose of a newly developed vitamin D3 100,000 IU in a soft capsule (Group 1) with the reference drug vitamin D3 100,000 IU oral solution in ampoule (Group 2) in healthy volunteers over a four-month period. The primary endpoint was the area under the curve (AUC) of serum 25-hydroxyvitamin-D (25(OH)D) concentrations on Day 112. This study was conducted in France from February to June 2014 in 53 young adults with a mean age of 26.9 years. At baseline, low mean serum 25(OH)D levels were observed in both groups (10.6 ng/mL in Group 1 and 9.0 ng/mL in Group 2). On Day 112, the AUC of serum 25(OH)D concentration was 2499.4 ± 463.8 nmol/mL (7.8 ± 0.2 for LogAUC) for Group 1 and 2152.3 ± 479.8 nmol/mL (7.6 ± 0.2 for LogAUC) for Group 2. Bioequivalence of the two treatments was not demonstrated. Superiority of vitamin D3 100,000 IU soft capsule was observed with p = 0.029 for AUC and p = 0.03 for LogAUC using a non-parametric Wilcoxon test. The profile of the serum 25(OH)D concentration showed a significant difference in favor of Group 1 on Days 1, 3, 7, 14 and 90. Mean serum 25(OH)D concentrations in Group 1 were between 20 and 30 ng/mL during the four-month period and under 20 ng/mL throughout the study in Group 2, except on Day 112. Mean Cmax for Group 1 was significantly higher (p = 0.002). Fourteen days were needed to reach Tmax by more than half the subjects in Group 1 compared to 45 days in Group 2. Both treatments were well tolerated, with no severe or related adverse events reported. In conclusion, the pharmacokinetic profile of the new formulation of vitamin D3 100,000 IU soft capsule is superior to that of the oral solution in ampoule. The new formulation increased serum 25(OH)D levels to above 20 ng/mL and maintained levels from 20 ng/mL to 30 ng/mL for four months in late winter and spring.

Pharmacokinetic interaction of calcitriol with 20(S)-protopanaxadiol in mice: Determined by LC/MS analysis.

The physiological and anti-cancer functions of vitamin D3 are accomplished primarily via 1α,25-dihydroxyvitamin D3 (calcitriol), whereas 20(S)-protopanaxadiol (aPPD) is a ginsenoside, which is isolated from Panax ginseng, with potential anti-cancer benefits. In the present study, we report a pharmacokinetic (PK) herb-nutrient interaction between calcitriol and aPPD in mice. A liquid chromatography mass spectrometry (LC/MS) method was developed using 4-phenyl-1,2,4-triazoline-3,5-dione derivatizing agent and we subsequently used the method to quantitate calcitriol in mouse serum. The limit of quantitation was 0.01 ng/ml which is approximately 100 fold lower than the previously reported assay from our laboratory. Calcitriol PK parameters were determined in non-tumor-bearing or C4-2 human prostate tumor-bearing nude mice following oral co-administration of calcitriol either alone or in combination with aPPD. Mice were pretreated with oral aPPD (70 mg/kg) or vehicle control twice daily for seven consecutive days, followed by a single oral dose of 4 µg/kg calcitriol alone or in combination with aPPD. Our PK results demonstrated that co-administration of calcitriol with aPPD (following pre-treatment with vehicle for seven days) resulted in a 35% increase in the area under the curve (AUC0-24 h) and a 41% increase in the maximum serum concentration (Cmax) compared to the calcitriol only group. aPPD therefore significantly increased calcitriol serum exposure. We also saw a reduction in the time required to reach Cmax. In contrast, calcitriol PK in mice co-administered with calcitriol and aPPD as well as those pretreated seven consecutive days with aPPD was no different than that determined for the mice that received vehicle for seven days as pre-treatment. Co-administration of calcitriol with aPPD therefore could increase health benefits of vitamin D3, however any increased risk of hypercalcemia, resulting from this combination approach, requires further investigation. Lastly, we surmise that a cytochrome P450 inhibition-based mechanism may contribute to the observed PK interaction.

Levels of serum sclerostin, FGF-23, and intact parathyroid hormone in postmenopausal women treated with calcitriol.

OBJECTIVE: This study aimed to determine the effect of calcitriol on serum concentrations of fibroblast growth factor-23 (FGF-23), sclerostin, intact parathyroid hormone (PTH), and handgrip strength in postmenopausal women with low bone mass. METHODS: A randomized, double-blind controlled trial was carried out among 141 postmenopausal women with low bone mass. Participants were randomized into two groups: 75 participants received calcitriol 0.5 µg/day and 66 participants received a placebo for 12 weeks. RESULTS: After 12-week calcitriol treatment, significant decreases in serum intact PTH (P=0.035) and sclerostin (P=0.039), as well as significant increases in serum creatinine (P=0.027), uric acid (P=0.032), 24-hour urinary calcium (P=0.0026), and left handgrip strength (P=0.03), were observed, compared to placebo group. Level of serum sclerostin was weakly but significantly positively correlated with serum PTH (r=0.277; P=0.01) and negatively correlated with 24-hour urinary calcium (r=-0.221; P=0.04) and left handgrip strength (r=-0.338; P=0.03) after calcitriol treatment. Multiple regression analysis demonstrated that decrease in serum sclerostin was associated with decrease in PTH serum level after calcitriol treatment (OR, 7.90; 95% CI, 2.28-27.42; P=0.002). However, no significant change in FGF-23 level was observed after calcitriol treatment. CONCLUSION: Calcitriol treatment yields a considerable decrease in serum sclerostin and significant increase of handgrip strength, and the change in serum sclerostin is regulated by serum PTH and by muscle strength.

In Vitro-In Vivo Evaluation of an Oral Ghost Drug Delivery Device for the Delivery of Salmon Calcitonin.

An orally administered site-specific Oral Ghost Drug Delivery (OGDD) device was developed and evaluated for the administration of salmon calcitonin. In vitro drug release studies have been undertaken using biorelevant media and aspirated gastrointestinal fluid from a large white pig in addition to characterization of a formulated trimethyl chitosan blend formulated and prepared into a loaded mini-pellet system. In vivo drug release analysis in a large white pig model has further been undertaken on the OGDD device and a commercial intramuscular injection to ascertain the release properties of the OGDD device in an animal model in comparison with the currently used treatment option for the administration of salmon calcitonin. Results of this study have detailed the success of the prepared system during both in vitro and in vivo analyses with the OGDD providing a greater control of release of salmon calcitonin when compared to the commercial product.