Dose translation between laboratory animals and human in preclinical and clinical phases of drug development

Bu-Shen-Fang-Chuan formula attenuates T-lymphocytes recruitment in the lung of rats with COPD through suppressing CXCL9/CXCL10/CXCL11-CXCR3 axis

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease characterized by irreversible airflow limitation. The current medications show limited effects on the decline of pulmonary function in COPD. Our multicenter clinical trial found that Bu-Shen-Fang-Chuan fomula (BSFCF), a Chinese herbal formula, markedly reduced the frequencies of acute exacerbation of COPD and delayed lung function decline. However, the underlying mechanisms are still unclear. In this study, we established a COPD rat model through a 6-month exposure to cigarette smoke (CS) and found that BSFCF (7.2 g/kg) effectively improved CS-induced reduction in pulmonary function and remarkably decreased the numbers of inflammatory cells in bronchoalveolar lavage fluid (BALF). Importantly, BSFCF treatment notably prevented the accumulation of T-lymphocytes (especially CD8⁺ T-cells) in the lung of COPD rats. RNA sequencing analysis of lung tissue demonstrated that CXCL9/CXCL10/CXCL11-CXCR3 chemokine axis in the lung of CS-exposed rats was significantly suppressed by BSFCF. Moreover, our Real-time PCR data verified that BSFCF evidently inhibited the mRNA expressions of CXCL9, CXCL10, CXCL11 and CXCR3. Conclusively, BSFCF markedly improved pulmonary function and attenuated CD8⁺ T-cells recruitment in the lung of CS-exposed rats, which were partially through inhibition of CXCL9/CXCL10/CXCL11-CXCR3 axis.

Development of Asialoglycoprotein Receptor-Targeted Nanoparticles for Selective Delivery of Gemcitabine to Hepatocellular Carcinoma

Selective targeting of anticancer drugs to the tumor site is beneficial in the pharmacotherapy of hepatocellular carcinoma (HCC). This study evaluated the prospective of galactosylated chitosan nanoparticles as a liver-specific carrier to improve the therapeutic efficacy of gemcitabine in HCC by targeting asialoglycoprotein receptors expressed on hepatocytes. Nanoparticles were formulated (G1–G5) by an ionic gelation method and evaluated for various physicochemical characteristics. Targeting efficacy of formulation G4 was evaluated in rats. Physicochemical characteristics exhibited by nanoparticles were optimal for administering and targeting gemcitabine effectively to the liver. The biphasic release behavior observed with G4 can provide higher drug concentration and extend the pharmacotherapy in the liver target site. Rapid plasma clearance of gemcitabine (70% in 30 min) from G4 was noticed in rats with HCC as compared to pure drug (p < 0.05). Higher uptake of gemcitabine predominantly by HCC (64% of administered dose; p < 0.0001) demonstrated excellent liver targeting by G4, while mitigating systemic toxicity. Morphological, biochemical, and histopathological examination as well as blood levels of the tumor marker, alpha-fetoprotein, in rats confirmed the curative effect of G4. In conclusion, this study demonstrated site-specific delivery and enhanced in vivo anti-HCC efficacy of gemcitabine by G4, which could function as promising carrier in hepatoma.

Mucoadhesive buccal film of almotriptan improved therapeutic delivery in rabbit model

Administration of almotriptan as an oral therapy is largely limited because of poor aqueous solubility and rather low bioavailability. The aim of present investigation was to formulate oral mucoadhesive film of almotriptan to improve the drug delivery and desired therapeutic effects. Placebo films (F1-F8) were prepared by varying the concentrations of Proloc 15 (7.5-15% w/v) and Eudragit RL 100/RS 100 (15-30% w/v) polymers. Physicomechanical and pharmaceutical characteristics of drug loaded films (FA1-FA4) were examined. Selected FA4 film was evaluated in vivo by assessing the pharmacokinetic profile and compared with oral therapy in rabbits. FA1-FA4 films exhibited excellent physicomechanical properties and rapid hydration. A biphasic and considerably greater drug release (p < 0.05) was observed in FA3 and FA4 films contain higher amount of hydrophilic polymer. The rate of permeation of almotriptan was found to be significantly higher in FA4 than FA3 film (p < 0.005). Fourier transform infrared spectral scan indicates no incompatibility exists between the drug and polymers used. Differential scanning calorimetry thermogram represents the evidence of almotriptan amorphization and molecular dispersion of it in the film. Scanning electron microscopy images shows that FA4 possess good morphological features and hence suitable for use in the buccal application. In vivo data demonstrated rapid and efficient absorption (p < 0.005) of almotriptan with greater AUC_0-12 (>2 folds, p < 0.0001) by FA4 film as compared to oral (control). In general, the data established the potential of FA4 film to improve the therapeutic delivery of almotriptan and offers a promising option in migraine therapy.

Medicines discovery for auditory disorders: Challenges for industry

Currently, no approved medicines are available for the prevention or treatment of hearing loss. Pharmaceutical industry productivity across all therapeutic indications has historically been disappointing, with a 90% chance of failure in delivering a marketed drug after entering clinical evaluation. To address these failings, initiatives have been applied in the three cornerstones of medicine discovery: target selection, clinical candidate selection, and clinical studies. These changes aimed to enable data-informed decisions on the translation of preclinical observations into a safe, clinically effective medicine by ensuring the best biological target is selected, the most appropriate chemical entity is advanced, and that the clinical studies enroll the correct patients. The specific underlying pathologies need to be known to allow appropriate patient selection, so improved diagnostics are required, as are methodologies for measuring in the inner ear target engagement, drug delivery and pharmacokinetics. The different therapeutic strategies of protecting hearing or preventing hearing loss versus restoring hearing are reviewed along with potential treatments for tinnitus. Examples of current investigational drugs are discussed to highlight key challenges in drug discovery and the learnings being applied to improve the probability of success of launching a marketed medicine.

Gellan Gum-Based Hydrogel for the Transdermal Delivery of Nebivolol: Optimization and Evaluation

Poor solubility and appreciable first-pass metabolism have limited the oral bioavailability of nebivolol. The objective of the current investigation was to design, formulate, and optimize a hydrogel-based transdermal system for nebivolol using factorial design and compare its pharmacokinetics with oral suspension. Hydrogel formulations (F1-F8) were prepared by varying the amounts of gellan gum, carbopol, and polyethylene glycol. A 23 full factorial design was used to assess the effect of independent variables such as gellan gum, carbopol, and polyethylene glycol 400 on dependent variables like viscosity, in vitro release, and ex vivo permeation after 2 h at two levels. Optimized gel (F7), containing nebivolol hydrochloride (75 mg), gellan gum (300 mg), carbopol (150 mg), polyethylene glycol 400 (20 µl), tween 80 (1 ml), ethanol (10 ml), and water (up to 30 ml) was selected and evaluated in albino rats. The physicochemical properties of F7 (pH: 7.1 ± 0.15, viscosity: 8943 ± 116 centipoise, drug content: 98.81% ± 2.16%) seem ideal for transdermal application. It was noticed that the concentration of carbopol has a more significant role than gellan gum in gel viscosity. A biphasic release pattern was exhibited by gels, and the release rate was mainly influenced by the concentration of gellan gum. Greater transdermal flux (30.86 ± 4.08 µg/cm2/h) was observed in F7 as compared with other prepared gels. Noticeable enhancement in AUC0-α value (986.52 ± 382.63 ng.h/ml; p < 0.01) of transdermal therapy (~2-fold higher compared with oral administration) established the potential of F7 to improve the rate and extent of nebivolol delivery. The overall results demonstrated here signify that F7 could be a feasible alternative to oral therapy of nebivolol.

Monounsaturated Fatty Acids in a High-Fat Diet and Niacin Protect from White Fat Dysfunction in the Metabolic Syndrome

SCOPE

Obesity is a principal causative factor of metabolic syndrome. Niacin potently regulates lipid metabolism. Replacement of saturated fatty acids by MUFAs or inclusion of omega-3 long-chain PUFAs in the diet improves plasma lipid levels. However, the potential benefits of niacin in combination with MUFAs or omega-3 long-chain PUFAs against white adipose tissue (WAT) dysfunction in the high fat diet (HFD)-induced metabolic syndrome are unknown.

METHODS AND RESULTS

Male Lep^ob/ob LDLR^-/- mice are fed a chow diet or HFDs based on milk cream (21% kcal), olive oil (21% kcal), or olive oil (20% kcal) plus 1% kcal from eicosapentaenoic and docosahexaenoic acids, including immediate-release niacin (1% w/v) in drinking water, for 8 weeks. Mice are then phenotyped. Dietary MUFAs are identified as positive regulators of adipose NAD⁺ signaling pathways by triggering NAD⁺ biosynthesis via the salvage pathway. This coexists with overexpression of genes involved in recognition of NAD⁺ and fatty acids, a surrounding lipid environment dominated by exogenous oleic acid and an alternatively activated macrophage profile, which culminate in a healthy expansion of WAT and improvement of several hallmarks that typify the metabolic syndrome.

CONCLUSION

Niacin in combination with dietary MUFAs can favor WAT homeostasis in the development of HFD-induced obesity and metabolic syndrome.

Effective Therapeutic Delivery and Bioavailability Enhancement of Pioglitazone Using Drug in Adhesive Transdermal Patch

The administration of pioglitazone as an oral therapy is restricted due to various challenges. The aim of the current investigation was to evaluate the suitability of pioglitazone in adhesive transdermal patch as an alternative delivery system, in order to improve therapeutic delivery. Drug in adhesive pioglitazone (2% w/w) transdermal patch were optimized for drug release, suitable adhesive, and skin permeation enhancer. The selected patch was examined for drug-loading capacity and the patch with greater pioglitazone (6% w/w) was evaluated in rat models. The release of pioglitazone was influenced by the tested adhesive and was shown to be significantly higher (p < 0.001) with patch, prepared using Duro-Tak 87-2516. The ex vivo permeation results substantiate the release data as a greater transdermal flux (15.67 ± 2.35 µg/cm²/h) was demonstrated in patch fabricated with Duro-Tak 87-2516. Skin penetration enhancers promoted the ex vivo transdermal delivery of pioglitazone, and was ~2 folds (p < 0.0001) higher with propylene glycol, as compared to patch without enhancer. The maximum solubility of pioglitazone in Duro-Tak 87-2516 was found to be 6% w/w. Increasing the drug content in patch enhanced the transdermal flux and was highest when the pioglitazone level was 6% w/w (72.68 ± 5.76 µg/cm²/h). In vivo pharmacokinetic data demonstrate that the AUC_0-α in transdermal application (13,506.51 ± 1649.92 ng·h/mL) was ~2 times higher (p < 0.0001) as compared to oral dosage form. In conclusion, the promising results observed here signifies that developed patch could be a viable alternative for oral therapy of pioglitazone.

Quantitative Prediction of Human Pharmacokinetics and Pharmacodynamics of CKD519, a Potent Inhibitor of Cholesteryl Ester Transfer Protein (CETP)

CKD519, a selective inhibitor of cholesteryl ester transfer protein(CETP), is undergoing development as an oral agent for the treatment of primary hypercholesterolemia and mixed hyperlipidemia. The aim of this study was to predict the appropriate efficacious dose of CKD519 for humans in terms of the inhibition of CETP activity by developing a CKD519 pharmacokinetic/pharmacodynamic (PK/PD) model based on data from preclinical studies. CKD519 was intravenously and orally administered to hamsters, rats, and monkeys for PK assessment. Animal PK models of all dose levels in each species were developed using mixed effect modeling analysis for exploration, and an interspecies model where allometric scaling was applied was developed based on the integrated animal PK data to predict the human PK profile. PD parameters and profile were predicted using in vitro potency and same-in-class drug information. The two-compartment first-order elimination model with Weibull-type absorption and bioavailability following the sigmoid E_max model was selected as the final PK model. The PK/PD model was developed by linking the interspecies PK model with the E_max model of the same-in-class drug. The predicted PK/PD profile and parameters were used to simulate the human PK/PD profiles for different dose levels, and based on the simulation result, the appropriate efficacious dose was estimated as 25 mg in a 60 kg human. However, there were some discrepancies between the predicted and observed human PK/PD profiles compared to the phase I clinical data. The huge difference between the observed and predicted bioavailability suggests that there is a hurdle in predicting the absorption parameter only from animal PK data.

Pinto Beans (Phaseolus vulgaris L.) Lower Non-HDL Cholesterol in Hamsters Fed a Diet Rich in Saturated Fat and Act on Genes Involved in Cholesterol Homeostasis

BACKGROUND

Pinto beans contain multiple active agents such as polyphenols, flavonoids, and saponins, and have been shown to lower cholesterol, but the mechanisms involved in this effect have not been explored.

OBJECTIVE

This study was to investigate the changes in cholesterol metabolism in response to whole pinto beans (wPB) and their hulls (hPB) supplemented into a diet rich in saturated fat and the molecular mechanisms potentially responsible for these effects in hamsters.

METHODS

Forty-four 9-wk-old male Golden Syrian hamsters were randomly assigned to 4 diet groups (n = 11), including a 5% (wt:wt) fat diet [normal-fat diet (NF)], a 15% (wt:wt) fat diet [diet rich in saturated fat (HSF), saturated fatty acids accounted for 70% of total fatty acids], or HSF supplemented with 5% (wt:wt) wPB or 0.5% (wt:wt) hPB for 4 wk. Plasma, liver, intestinal, and fecal samples were collected to evaluate multiple cholesterol markers and gene targets.

RESULTS

The plasma non-high-density lipoprotein (non-HDL) concentration was significantly reduced in the wPB- and hPB-supplemented groups by 31.9 ± 3.5% and 53.6 ± 3.2%, respectively, compared with the HSF group (P < 0.01), to concentrations comparable with the NF group. The wPB-supplemented hamsters had significantly lower liver cholesterol (45.1%, P < 0.001) and higher fecal cholesterol concentrations (94.8%, P = 0.001) than those fed the HSF. The expressions of hepatic 3-hydroxy-3-methylglutaryl CoA reductase (Hmgcr) and small intestinal acyl-coenzyme A: cholesterol acyltransferase 2 (Acat2) were significantly decreased in animals administered wPB (by 89.1% and 63.8%, respectively) and hPB (by 72.9% and 47.7%, respectively) compared with their HSF-fed counterparts (P < 0.05). The wPB normalized the expression of Acat2 to the level of the NF group.

CONCLUSION

Pinto beans remediated high cholesterol induced by HSF in male hamsters by decreasing hepatic cholesterol synthesis and intestinal cholesterol absorption, effects which were partially exerted by the hulls.

Nanoemulsion Based Vehicle for Effective Ocular Delivery of Moxifloxacin Using Experimental Design and Pharmacokinetic Study in Rabbits

Nanoemulsion is one of the potential drug delivery strategies used in topical ocular therapy. The purpose of this study was to design and optimize a nanoemulsion-based system to improve therapeutic efficacy of moxifloxacin in ophthalmic delivery. Moxifloxacin nanoemulsions were prepared by testing their solubility in oil, surfactants, and cosurfactants. A pseudoternary phase diagram was constructed by titration technique and nanoemulsions were obtained with four component mixtures of Tween 80, Soluphor^® P, ethyl oleate and water. An experiment with simplex lattice design was conducted to assess the influence of formulation parameters in seven nanoemulsion formulations (MM1–MM7) containing moxifloxacin. Physicochemical characteristics and in vitro release of MM1–MM7 were examined and optimized formulation (MM3) was further evaluated for ex vivo permeation, antimicrobial activity, ocular irritation and stability. Drug pharmacokinetics in rabbit aqueous humor was assessed for MM3 and compared with conventional commercial eye drop formulation (control). MM3 exhibited complete drug release in 3 h by Higuchi diffusion controlled mechanism. Corneal steady state flux of MM3 (~32.01 µg/cm²/h) and control (~31.53 µg/cm²/h) were comparable. Ocular irritation study indicated good tolerance of MM3 and its safety for ophthalmic use. No significant changes were observed in the physicochemical properties of MM3 when stored in the refrigerator for 3 months. The greater aqueous humor concentration (C_max; 555.73 ± 133.34 ng/mL) and delayed T_max value (2 h) observed in MM3 suggest a reduced dosing frequency and increased therapeutic efficacy relative to control. The area under the aqueous humor concentration versus time curve (AUC_{0–8 h}) of MM3 (1859.76 ± 424.51 ng·h/mL) was ~2 fold higher (p < 0.0005) than the control, suggesting a significant improvement in aqueous humor bioavailability. Our findings suggest that optimized nanoemulsion (MM3) enhanced the therapeutic effect of moxifloxacin and can therefore be used as a safe and effective delivery vehicle for ophthalmic therapy.

Tissue-dependent effects of cis-9,trans-11- and trans-10,cis-12-CLA isomers on glucose and lipid metabolism in adult male mice

Mixtures of the two major conjugated linoleic acid (CLA) isomers trans-10,cis-12-CLA and cis-9,trans-11-CLA are used as over the counter supplements for weight loss. Because of the reported adverse effects of CLA on insulin sensitivity in some mouse studies, we sought to compare the impact of dietary t10c12-CLA and c9t11-CLA on liver, adipose tissue, and systemic metabolism of adult lean mice. We fed 8 week-old C57Bl/6J male mice with low fat diets (10.5% Kcal from fat) containing 0.8% t10c12-CLA or c9t11-CLA for 9 or 38 days. Diets containing c9t11-CLA had minimal impact on the endpoints studied. However, 7 days after starting the t10c12-CLA diet, we observed a dramatic reduction in fat mass measured by NMR spectroscopy, which interestingly rebounded by 38 days. This rebound was apparently due to a massive accumulation of lipids in the liver, because adipose tissue depots were visually undetectable. Hepatic steatosis and the disappearance of adipose tissue after t10c12-CLA feeding was associated with elevated plasma insulin levels and insulin resistance, compared to mice fed a control diet or c9t11-CLA diet. Unexpectedly, despite being insulin resistant, mice fed t10c12-CLA had normal levels of blood glucose, without signs of impaired glucose clearance. Hepatic gene expression and fatty acid composition suggested enhanced hepatic de novo lipogenesis without an increase in expression of gluconeogenic genes. These data indicate that dietary t10c12-CLA may alter hepatic glucose and lipid metabolism indirectly, in response to the loss of adipose tissue in mice fed a low fat diet.

Proniosomal gel for transdermal delivery of lornoxicam: optimization using factorial design and in vivo evaluation in rats

OBJECTIVE

Clinical utility of lornoxicam in oral therapy is primarily restricted by the low solubility and gastric adverse effects. This study evaluated the prospective of optimized proniosomal gel to improve the clinical efficacy of lornoxicam and compare with oral therapy.

METHODS

Proniosomes were formulated by coacervation phase separation technique using span 60, lecithin and cholesterol. A four-factor three-level Box-Behnken design was used to evaluate the effect of amount of four independent variables; span 60 (X₁), cholesterol (X₂), lecithin (X₃) and lornoxicam (X₄) on response variables; vesicle size (Y₁), entrapment efficiency (Y₂) and transdermal flux (Y₃). The selected proniosomal gel (F19) was characterized, and evaluated for the transdermal efficacy by ex vivo and in vivo experiments.

RESULTS

Optimization study signifies that amount of formulation components (span 60, cholesterol, lecithin and lornoxicam) influence the vesicle size, entrapment efficiency and/or transdermal flux. Optimized formulation F19 exhibited nano size with high entrapment efficiency, adequate zeta potential, greater transdermal flux and better stability (at refrigerated conditions). The entrapment of lornoxicam in the bilayers of proniosome vesicles was confirmed by differential scanning calorimeter. Release profile of F19 was distinct (p < 0.001) from gel prepared using hydroxypropyl methylcellulose (control) and displayed steady lornoxicam release by Fickian diffusion. Transdermal administration of F19 significantly inhibited the carrageenan induced hind-paw edema in rats as compared to oral lornoxicam group.

CONCLUSIONS

The data observed in this study demonstrated that the developed proniosomal gel (F19) improved the clinical efficacy of lornoxicam as compared to oral therapy. Graphical Abstract Proniosomal gel for transdermal delivery of lornoxicam: optimization using factorial design and in vivo evaluation in rats.