Improved oral bioavailability of poorly water-soluble glimepiride by utilizing microemulsion technique

Preparation, in vitro and in vivo evaluation of a novel mitiglinide microemulsions

This study aimed to prepare an o/w mitiglinide microemulsion (MTGME) to improve the drug solubility and bioavailability. The formulation of o/w MTGME was optimized by the solubility study of drug, pseudo-ternary phase diagram and Box-Behnken design successively. MTGME was characterized by dynamic laser light scattering (DLS), zeta potential and transmission electron microscopy (TEM), moreover, the storage stability, pharmacodynamics and pharmacokinetics were investigated. The optimal prescription for MTGME consisted of Maisine 35-1 (oil), Cremophor EL (surfactant) and propylene glycol (PG, cosurfactant). MTGME with a spherical dimension of 58.1 ± 5.86 nm was stable when stored at 4 °C for 3 months. The blood glucose levers (BGL) of diabetic mice were uniformly and significantly decreased by intragastric (i.g.) administration of 1-4 mg/kg MTGME, in which BGL (i.g. 4 mg/kg MTGME) was reduced by 69% during 24 h. The pharmacokinetics study of MTGME (i.g., 20 mg/kg) in Wistar rats showed higher plasma drug concentration (Cmax, 2.9 folds), larger area under curve (AUC, 4.6 folds) and oral bioavailability than those of MTG suspensions. Generally, the MTGME (o/w) showed good effect on controlling hyperglycemia. Therefore, microemulsion can be used as an effective oral drug delivery system to improve the bioavailability of MTG.

Double layer spherical nanoparticles with hyaluronic acid coating to enhance oral delivery of exenatide in T2DM rats

Soybean phospholipid was used as an amphiphilic material to form reverse micelles (RMs) in medium glycerol monolinoleate (Maisine) with Exenatide (EXT.) encapsulated in the polar core formed by the hydrophilic part of phospholipid. Cremopher RH40 and caprylocaproyl macrogol-8 glycerides EP/caprylocaproyl polyoxyl-8 glycerides NF (Labrasol) were added as surfactants to prepare reverse micelles-self emulsifying drug delivery system (RMs-SEDDS). On this basis, oil in water (O/W) emulsion was further prepared. By adding DOTAP, the surface of the emulsion was positively charged. Finally, hyaluronic acid wrapping in the outermost layer by electrostatic adsorption and reverse micelles-O/W-sodium hyaluronate (RMs-O/W-HA) nanoparticles containing Exenatide were prepared. RMs-SEDDS was spherical with an average particle size of 213.6 nm and RMs-O/W-HA was double-layered spherical nanoparticle with an average particle size of 309.2 nm. HA coating enhanced the adhesion of nanoparticles (NPs), and RMs-O/W-HA increased cellular uptake through CD44-mediated endocytosis. Pharmacodynamics results showed that RMs-SEDDS and RMs-O/W-HA could reduce blood glucose in type 2 diabetic rats, protect pancreatic β cells to a certain extent, and relieve insulin resistance and hyperlipemia complications with good safety.

Development of Osthole-Loaded Microemulsions as a Prospective Ocular Delivery System for the Treatment of Corneal Neovascularization: In Vitro and In Vivo Assessments

Osthole (OST), a natural coumarin compound, has shown a significant inhibitory effect on corneal neovascularization (CNV). But, its effect on treating CNV is restricted by its water insolubility. To overcome this limitation, an OST-loaded microemulsion (OST-ME) was created to improve the drug's therapeutic effect on CNV after topical administration. The OST-ME formulation comprised Capryol-90 (CP-90), Cremophor® EL (EL-35), Transcutol-P (TSP) and water, and sodium hyaluronate (SH) was also included to increase viscosity. The OST-ME had a droplet size of 16.18 ± 0.02 nm and a low polydispersity index (0.09 ± 0.00). In vitro drug release from OST-ME fitted well to the Higuchi release kinetics model. Cytotoxicity assays demonstrated that OST-ME was not notably toxic to human corneal epithelial cells (HCECs), and the formulation had no irritation to rabbit eyes. Ocular pharmacokinetics studies showed that the areas under the concentration-time curves (AUC0-t) in the cornea and conjunctiva were 19.74 and 63.96 μg/g*min after the administration of OST-ME, both of which were 28.2- and 102.34-fold higher than those after the administration of OST suspension (OST-Susp). Moreover, OST-ME (0.1%) presented a similar therapeutic effect to commercially available dexamethasone eye drops (0.025%) on CNV in mouse models. In conclusion, the optimized OST-ME exhibited good tolerance and enhanced 28.2- and 102.34-fold bioavailability in the cornea and conjunctiva tissues compared with suspensions in rabbit eyes. The OST-ME is a potential ocular drug delivery for anti-CNV.

Optimization of Potential Nanoemulgels for Boosting Transdermal Glimepiride Delivery and Upgrading Its Anti-Diabetic Activity

Transdermal drug delivery has been widely adopted as a plausible alternative to the oral route of administration, especially for drugs with poor systemic bioavailability. The objective of this study was to design and validate a nanoemulsion (NE) system for transdermal administration of the oral hypoglycemic drug glimepiride (GM). The NEs were prepared using peppermint/bergamot oils as the oil phase and tween 80/transcutol P as the surfactant/co-surfactant mixture (S_mix). The formulations were characterized using various parameters such as globule size, zeta potential, surface morphology, in vitro drug release, drug-excipient compatibility studies, and thermodynamic stability. The optimized NE formulation was then incorporated into different gel bases and examined for gel strength, pH, viscosity, and spreadability. The selected drug-loaded nanoemulgel formulation was then screened for ex vivo permeation, skin irritation, and in vivo pharmacokinetics. Characterization studies revealed the spherical shape of NE droplets with an average size of ~80 nm and a zeta potential of -11.8 mV, which indicated good electrokinetic stability of NE. In vitro release studies revealed enhanced drug release from the NE formulation compared to the plain drug. GM-loaded nanoemulgel showed a 7-fold increment in drug transdermal flux compared to plain drug gel. In addition, the GM-loaded nanoemulgel formulation did not elicit any signs of inflammation and/or irritation on the applied skin, suggesting its safety. Most importantly, the in vivo pharmacokinetic study emphasized the potential of nanoemulgel formulation to potentiate the systemic bioavailability of GM, as manifested by a 10-fold rise in the relative bioavailability compared to control gel. Collectively, transdermal NE-based GM gel might represent a promising alternative to oral therapy in the management of diabetes.

Influences of Glimepiride Self-Nanoemulsifying Drug Delivery System Loaded Liquisolid Tablets on the Hypoglycemic Activity and Pancreatic Histopathological Changes in Streptozotocin-Induced Hyperglycemic Rats

The development of an oral anti-diabetic medication characterized by enhanced hypoglycemic activity is in high demand. The goal was to study the hypoglycemic activity and pancreatic histopathology after the black-seed-based self-nanoemulsifying drug delivery system (SNEDDS) loaded with glimepiride liquisolid tablets to diabetic rats. The solubility of glimepiride in various vehicles was investigated. An optimization SNEDDS formulation was developed using a mixture of the experimental design approach. Box-Behnken design (BBD) was used to develop glimepiride liquisolid tablets utilizing Avicel PH 101 and Neusilin as a carrier mixture and FujiSil as a coating material. The quality attributes of the prepared tablets were assessed. Following the administration of the optimized tablets to diabetic rats, the pharmacodynamics and histopathological changes were investigated and compared to a commercial drug product. Results revealed that the optimized SNEDDS formulation that contains 15.43% w/w black seed oil, 40% w/w Tween 80, and 44.57% w/w Polyethylene glycol 400 showed an average droplet size of 34.64 ± 2.01 nm and a drug load of 36.67 ± 3.13 mg/mL. The optimized tablet formulation contained 0.31% Avicel in the carrier mixture, a 14.99 excipient ratio, and 8% superdisintegrant. Pre- and post-compression properties were satisfactory, and the optimized glimepiride liquisolid tablet showed a two-fold increase in dissolution. The optimized tablet demonstrated superior pharmacodynamics. The pancreatic tissues of the group treated with the optimized tablet displayed normal histological structure. The obtained data offered a commercially viable alternative for manufacturing solid dosage forms containing water-insoluble drugs, but additional clinical research is required.

Characterization and antimicrobial activity of spice extract-loaded algal microcomposites based on the microemulsion technique

In recent years, with the increase in knowledge and awareness, people's efforts to return to nature have increased in the field of medical science and cosmetics industry. Spices, sumac and coriander, grown and frequently used in Turkey, have different bioactive effects. Microalgae are preferred in the treatment of skin problems. The aim of this study was to synthesize algae microcomposites that were effective against bacterial infections, prepared based on microemulsion technique and loaded with spice extract. Microemulsion formulations were prepared by the titration method. Aqueous and ethanolic extractions of sumac/coriander were carried out using the ultrasonic-assisted extraction method. Twenty-four different algal microcomposites loaded with extracts were synthesized. The disk diffusion method was used to determine the antimicrobial activity. The DPPH free radical scavenging activities, the total phenolic content (TPSC), and the characteristics (FT-IR) of the microcomposites were investigated. In addition, the chemical contents of extracts were determined by the GC-MS method. Aqueous extracts of both sumac and coriander were highly effective against Escherichia coli (ES DII). The highest antimicrobial activity against Staphylococcus aureus (F6 III) was obtained with M9 (microcomposite containing ethanolic extract of sumac) and M15 (microcomposite containing aqueous extract of coriander). The highest TPSC value (6.025 mg GAE/gr) was detected in the aqueous extract of coriander. The DPPH radical scavenging activities of coriander extracts were lower than those of sumac extracts. It has been determined that the spices contain organic (propanoic, butanoic, malic and benzoic) acids and fatty (palmitic, oleic and myristic) acids. According to the results of FT-IR spectroscopy, microcomposites prepared with sumac and coriander extracts were successfully synthesized. The synthesized algae-based microcomposites have properties that could be in the green-labeled bio-based category.

Sorafenib-loaded nanostructured lipid carriers for topical ocular therapy of corneal neovascularization: development, in-vitro and in vivo study

Sorafenib (SRB), a multikinase inhibitor, is effective in reducing experimental corneal neovascularization (CNV) after oral administration; however, its therapeutic use in ocular surface disorders is restricted due to poor solubility and limited bioavailability. This study aimed to develop and optimize SRB-loaded nanostructured lipid carriers (SRB-NLCs) for topical ocular delivery by a central composite design response surface methodology (CCD-RSM). It was spherical and uniform in morphology with an average particle size of 111.87 ± 0.93 nm and a narrow size distribution. The in vitro drug release from the released SRB-NLC formulation was well fitted to Korsmeyer Peppas release kinetics. The cell counting kit-8 (CCK-8) cell viability assay demonstrated that SRB-NLC was not obviously cytotoxic to human corneal epithelial cells (HCECs). An in vivo ocular irritation test showed that SRB-NLC was well tolerated by rabbit eyes. Ocular pharmacokinetics revealed 6.79-fold and 1.24-fold increase in the area under concentration-time curves (AUC_0-12h) over 12 h in rabbit cornea and conjunctiva, respectively, treated with one dose of SRB-NLC compared with those treated with SRB suspension. Moreover, SRB-NLC (0.05% SRB) and dexamethasone (0.025%) similarly suppressed corneal neovascularization in mice. In conclusion, the optimized SRB-NLC formulation demonstrated excellent physicochemical properties and good tolerance, sustained release, and enhanced ocular bioavailability. It is safe and potentially effective for the treatment of corneal neovascularization.

Synthesized nano particles of glimepiride via spray freezing into cryogenic liquid: characterization, antidiabetic activity, and bioavailability

The aim of this work was to formulate glimepiride (class II drug) which is characterized by low solubility and high permeability as nanostructured particles using a cryogenic technique with an aid of water-soluble polymer to improve its aqueous solubility and hence its bioavailability. 27 formula of glimepiride nano size particles were prepared by a spray freezing into cryogenic liquid (SCFL) using poly vinyl pyrrolidone K-30 (PVP K-30); that three drug polymer ratio (1:1, 1:2, and 1:3), with three different volumes of feeding solution (50, 100, 150 mL), at three flow rates (10, 20, and 30 mL/min). The prepared formulations were evaluated for production yield, particle size, zeta potential, drug content, release rate, in vivo hypoglycemic activity, and bioavailability. All prepared formulations showed high production yield and drug content ranged between 91.1 ± 3.4% and 94.3 ± 1.8% and 95.1 ± 2.8% and 97.1 ± 2.5%, respectively. The mean particles size was ranged between 280 ± 62 nm and 520 ± 30 nm. The results of in vitro release study revealed significant enhancement in the solubility of prepared formulations compared with the pure drug. It was found that optimal formula showed a significant reduction in blood glucose levels in diabetic rats, and 1.79-fold enhancements in oral bioavailability compared with market tablets. Nanoparticle prepared by SCFL method is an encouraging formula for improving the solubility and the bioavailability of glimepiride.

Development of 3D-Printed, Liquisolid and Directly Compressed Glimepiride Tablets, Loaded with Black Seed Oil Self-Nanoemulsifying Drug Delivery System: In Vitro and In Vivo Characterization

Glimepiride is characterized by an inconsistent dissolution and absorption profile due to its limited aqueous solubility. The aim of this study was to develop glimepiride tablets using three different manufacturing techniques, as well as to study their quality attributes and pharmacokinetics behavior. Black seed oil based self-nanoemulsifying drug delivery system (SNEDDS) formulation was developed and characterized. Glimepiride liquisolid and directly compressed tablets were prepared and their pre-compression and post-compression characteristics were evaluated. Semi-solid pastes loaded with SNEDDS were prepared and used to develop three-dimensional printing tablets utilizing the extrusion technique. In vivo comparative pharmacokinetics study was conducted on Male Wistar rats using a single dose one-period parallel design. The developed SNEDDS formulation showed a particle size of 45.607 ± 4.404 nm, and a glimepiride solubility of 25.002 ± 0.273 mg/mL. All the studied tablet formulations showed acceptable pre-compression and post-compression characteristics and a difference in their in vitro drug release behavior. The surface of the liquisolid and directly compressed tablets was smooth and non-porous, while the three-dimensional printing tablets showed a few porous surfaces. The inner structure of the liquisolid tablets showed some cracks and voids between the incorporated tablet ingredients while that of the three-dimensional printing tablets displayed some tortuosity and a gel porous-like structure. Most of the computed pharmacokinetic parameters improved with the liquisolid and three-dimensional printed tablets. The relative bioavailabilities of the three-dimensional printed and liquisolid tablets compared to commercial product were 121.68% and 113.86%, respectively. Therefore, the liquisolid and three-dimensional printed tablets are promising techniques for modifying glimepiride release and improving in vivo performance but more clinical investigations are required.

Development of a naringenin microemulsion as a prospective ophthalmic delivery system for the treatment of corneal neovascularization: in vitro and in vivo evaluation

Naringenin, a flavonoid, possesses antiangiogenic potential and inhibits corneal neovascularization (CNV); however, its therapeutic use is restricted due to poor solubility and limited bioavailability. In this study, we developed a naringenin microemulsion (NAR-ME) for inhibiting CNV. NAR-ME formulation was composed of triacetin (oil phase), Cremophor RH40 (CRH40), PEG400, and water, its droplet size was 13.22 ± 0.13 nm with a narrow size distribution (0.112 ± 0.0014). The results demonstrated that NAR-ME released higher and permeated more drug than NAR suspension (NAR-Susp) in in vitro drug release and ex vivo corneal permeation study. Human corneal epithelial cells (HCECs) toxicity study showed no toxicity with NAR-ME, which is consistent with the result of ocular irritation study. NAR-ME had high bioavailability 1.45-fold, 2.15-fold, and 1.35-fold higher than NAR-Susp in the cornea, conjunctiva, and aqueous humor, respectively. Moreover, NAR-ME (0.5% NAR) presented efficacy comparable to that of dexamethasone (0.025%) in the inhibition of CNV in mice CNV model induced by alkali burning, resulting from the attenuation of corneal vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP-14) expression. In conclusion, the optimized NAR-ME formulation demonstrated excellent physicochemical properties and good tolerance, enhanced ocular bioavailability and corneal permeability. This formulation is promising, safe, and effective for the treatment of CNV.

Development of Multi-Compartment 3D-Printed Tablets Loaded with Self-Nanoemulsified Formulations of Various Drugs: A New Strategy for Personalized Medicine

This work aimed to develop a three-dimensional printed (3DP) tablet containing glimepiride (GLMP) and/or rosuvastatin (RSV) for treatment of dyslipidemia in patients with diabetes. Curcumin oil was extracted from the dried rhizomes of Curcuma longa and utilized to develop a self-nanoemulsifying drug delivery system (SNEDDS). Screening mixture experimental design was conducted to develop SNEDDS formulation with a minimum droplet size. Five different semi-solid pastes were prepared and rheologically characterized. The prepared pastes were used to develop 3DP tablets using extrusion printing. The quality attributes of the 3DP tablets were evaluated. A non-compartmental extravascular pharmacokinetic model was implemented to investigate the in vivo behavior of the prepared tablets and the studied marketed products. The optimized SNEDDS, of a 94.43 ± 3.55 nm droplet size, was found to contain 15%, 75%, and 10% of oil, polyethylene glycol 400, and tween 80, respectively. The prepared pastes revealed a shear-thinning of pseudoplastic flow behavior. Flat-faced round tablets of 15 mm diameter and 5.6–11.2 mm thickness were successfully printed and illustrated good criteria for friability, weight variation, and content uniformity. Drug release was superior from SNEDDS-based tablets when compared to non-SNEDDS tablets. Scanning electron microscopy study of the 3DP tablets revealed a semi-porous surface that exhibited some curvature with the appearance of tortuosity and a gel porous-like structure of the inner section. GLMP and RSV demonstrated relative bioavailability of 159.50% and 245.16%, respectively. Accordingly, the developed 3DP tablets could be considered as a promising combined oral drug therapy used in treatment of metabolic disorders. However, clinical studies are needed to investigate their efficacy and safety.

Development and in vitro and in vivo evaluations of a microemulsion formulation for the oral delivery of oxaprozin

BACKGROUND

Oxaprozin is labeled as a Class II drug in the biopharmaceutical classification system, and its poor solubility in the entire gastrointestinal tract may be the main reason for its poor oral absorption capacity.

OBJECTIVE

The purpose of this study was to develop an oxaprozin formulation to enhance its oral absorption.

METHOD

Oxaprozin-loaded microemulsions were prepared using the titration method and pseudoternary phase diagram. Characterization experiments were performed on microemulsion preparations, including pH, particle size, shape, zeta potential and stability (thermodynamic, dilution, and differential scanning calorimetry). Then, the in vitro release of the microemulsion and in vivo pharmacokinetics in rats were evaluated.

RESULTS

Several microemulsion formulations were prepared. The optimal formulation was 15% oleoyl macrogolglycerides, 35% Tween 20/isopropanol (Km=2) and 50% distilled water. Its particle size met the requirements, and it had a spherical shape with a negatively charged surface. This microemulsion-loaded drug was applied to in vitro release and in vivo pharmacokinetic experiments at 7.47 mg/mL. In vitro release of the oxaprozin-loaded microemulsion best fit the first-order model, while the microemulsion preparation had a certain sustained release effect. In vivo pharmacokinetic experiments indicated that the microemulsion formulation significantly delayed the peak time of the blood concentration and simultaneously prolonged the half-life of drug elimination.

CONCLUSION

The obtained data revealed satisfactory results for this novel microemulsion of oxaprozin, which is very meaningful for clinical trials.

Herbal Drugs and Natural Products in the light of Nanotechnology and Nanomedicine for Developing Drug Formulations

Natural products and medicinal plants have played a vital role in providing healthcare and ensuring well-being for many civilizations since antiquity. It is estimated that around 50% of drugs in the market have a natural product origin especially medicinal plants and herbal drugs, animals, fungi, and marine organisms. Some of these biologically active constituents of extracts have low absorption and distribution which, as a result, lead to loss of bioavailability and efficacy and might hamper their applications in the clinic. To overcome these impediments for the formulation of herbal drugs, food supplements, and essential oils, several nanomedical approaches such as liposomes, microemulsions, polymeric nanoparticles, solid lipid nanoparticles (SLNs), liquid crystal systems (LC), and precursor systems for liquid crystals (PSLCs) have been proposed. Nanoparticles have been used to modify and ameliorate the pharmacokinetic and pharmacodynamic properties of different drugs, thus incorporating biotechnological systems may be useful to enhance the bioavailability and bioactivity of herbal drug formulations. Consequently, essential for any natural compounds is the extent of its absorption after being ingested and its ability to be distributed in various tissues or organs of the body. The present review article aims to give an overview of the recent advancements in developing herbal drug formulations based on nanoparticle technologies.

Design of experiments (DoE) to develop and to optimize nanoparticles as drug delivery systems

Nanotechnology has been widely applied to develop drug delivery systems to improve therapeutic performance. The effectiveness of these systems is intrinsically related to their physicochemical properties, so their biological responses are highly susceptible to factors such as the type and quantity of each material that is employed in their synthesis and to the method that is used to produce them. In this context, quality-oriented manufacturing of nanoparticles has been an important strategy to understand and to optimize the factors involved in their production. For this purpose, Design of Experiment (DoE) tools have been applied to obtain enough knowledge about the process and hence achieve high-quality products. This review aims to set up the bases to implement DoE as a strategy to improve the manufacture of nanocarriers and to discuss the main factors involved in the production of the most common nanocarriers employed in the pharmaceutical field.

Preparation and characterization of sorafenib-loaded microprecipitated bulk powder for enhancing oral bioavailability

The aim of this study was to prepare and evaluate Eudragit-based microprecipitated bulk powder (MBP) formulations to enhance the oral bioavailability of sorafenib. Cationic Eudragit E PO and anionic Eudragit S100 were selected for MBP preparation. Ursodeoxycholic acid (UDCA)-incorporated MBP was also prepared to study the synergistic effect of UDCA in enhancing the bioavailability of sorafenib. Sorafenib-loaded MBPs were successfully prepared by a pH-controlled precipitation method using an aqueous antisolvent. Submicron-sized particles of MBPs were observed by scanning electron microscopy, and the amorphous form of sorafenib in MBPs was confirmed by powder X-ray diffraction. MBPs of cationic and anionic Eudragits showed different in vitro dissolution and pharmacokinetic profiles in rats. Sorafenib in Eudragit E PO-based MBP (E PO-MBP) was rapidly dissolved at low pH conditions (pH 1.2 and 4.0), but was precipitated again at pH 4.0 within 4 h. Dissolution of sorafenib from Eudragit S100-based MBP (S100-MBP) was high at pH 7.4 and did not precipitate for up to 4 h. After oral administration to rats, all MBPs, compared with powder, improved the oral absorption of sorafenib, with S100-MBP showing 1.5-fold higher relative oral bioavailability than E PO-MBP. Moreover, incorporation of UDCA in S100-MBP (S100-UDCA-MBP) further increased the C_max and oral bioavailability of sorafenib, although the dissolution was not significantly different from that of S100-MBP. Taken together, Eudragit-based MBP formulations could be a promising strategy for enhancing the oral bioavailability of sorafenib.

Development and Characterization of Glimepiride Novel Solid Nanodispersion for Improving Its Oral Bioavailability

Glimepiride is an antidiabetic drug which is one of the third generation sulfonylureas. It belongs to class II, according to the BCS (Biopharmaceutical Classification System), which is characterized by low solubility and high permeability. The aim of this work was to formulate glimepiride as solid dispersion using water-soluble carriers to enhance its aqueous solubility and thus enhance its bioavailability. Nine formulations of glimepiride solid dispersion were prepared by a solvent evaporation technique using three different carriers (mannitol, polyethylene glycol 6000, and β-cyclodextrin) with three different drug carrier ratio (1:1, 1:3, and 1:6). Formulation variables were optimized using 32 full factorial design. The prepared formulations were evaluated for production yield, drug content, micromeritic properties, thermal analysis, in-vitro release, and in-vivo hypoglycemic effect. All prepared formulations showed high production yield ranged from 98.4 ± 2.8 to 99.8 ± 2.2% and high drug content in the range of 97.2 ± 3.2 to 99.6 ± 2.1%. The micromeritic properties revealed that all prepared glimepiride formulations showed good flowability. The differential scanning calorimetry study revealed the presence of the drug in the more soluble amorphous form. In accordance with the results of in vitro release study, it was found that the solubility of glimepiride was increased by increasing the drug carrier ratio, compared with the pure form of the drug. It was found that F9 showed a high and rapid reduction in blood glucose levels in diabetic rats, which indicated the success of a solid dispersion technique in improving the solubility and hence the bioavailability of glimepiride.

Liquiritigenin-Loaded Submicron Emulsion Protects Against Doxorubicin-Induced Cardiotoxicity via Antioxidant, Anti-Inflammatory, and Anti-Apoptotic Activity

Background

The clinical use of doxorubicin (DOX) is severely limited due to its cardiotoxicity. Thus, there is a need for prophylactic and treatment strategies against DOX-induced cardiotoxicity.

Purpose

The purpose of this study was to develop a liquiritigenin-loaded submicron emulsion (Lq-SE) with enhanced oral bioavailability and to explore its efficacy against DOX-induced cardiotoxicity.

Methods

Lq-SE was prepared using high-pressure homogenization and characterized using several analytical techniques. The formulation was optimized by central composite design response surface methodology (CCD-RSM). In vivo pharmacokinetic studies, biochemical analyses, reactive oxygen species (ROS) assays, histopathologic assays, and Western blot analyses were performed.

Results

Each Lq-SE droplet had a mean particle size of 221.7 ± 5.80 nm, a polydispersity index (PDI) of 0.106 ± 0.068 and a zeta potential of -28.23 ± 0.42 mV. The area under the curve (AUC) of Lq-SE was 595% higher than that of liquiritigenin (Lq). Lq-SE decreased the release of serum cardiac enzymes and ameliorated histopathological changes in the hearts of DOX-challenged mice. Lq-SE significantly reduced oxidative stress by adjusting the levels of ROS, increasing the activity of antioxidative enzymes and inhibiting the protein expression of NOX4 and NOX2. Furthermore, Lq-SE significantly improved the inflammatory response through the mitogen-activated protein kinase (MAPK)/nuclear factor-κB (NF-κB) signalling pathway and induced cardiomyocyte apoptosis.

Conclusion

Lq-SE could be used as an effective cardioprotective agent against DOX in chemotherapy to enable better treatment outcomes.

Promises of Nanotherapeutics in Obesity

The application of nanotechnology to medicine promises a wide range of new tools and possibilities, from earlier diagnostics and improved imaging, to better, more efficient, and more targeted therapies. This emerging field could help address obesity, with advances in drug delivery, nutraceuticals, and genetic and epigenetic therapeutics. Its application to obesity is still largely in the development phase. Here, we review the novel angle of nanotech applied to human consumable products and their specific applications to addressing obesity through nutraceuticals, with respect to benefits and limitations of current nanotechnology methods. Further, we review potential future applications to deliver genetic and epigenetic miRNA therapeutics. Finally, we discuss future directions, including theranostics, combinatory therapy, and personalized medicine.

Highly Soluble Glimepiride and Irbesartan Co-amorphous Formulation with Potential Application in Combination Therapy

One-third of the population of the USA suffers from metabolic syndrome (MetS). Treatment of patients with MetS regularly includes drugs prescribed simultaneously to treat diabetes and cardiovascular diseases. Therefore, the development of novel multidrug formulations is recommended. However, the main problem with these drugs is their low solubility. The use of binary co-amorphous systems emerges as a promising strategy to increase drug solubility. In the present study, irbesartan (IBS) and glimepiride (GMP), class II active pharmaceutical ingredients (API), widely used in the treatment of arterial hypertension and diabetes, were selected to develop a novel binary co-amorphous system with remarkable enhancement in the dissolution of both APIs. The phase diagram of IBS-GMP was constructed and co-amorphous systems were prepared by melt-quench, in a wide range of compositions. Dissolution profile (studied at pH 1.2 and 37°C for mole fractions 0.01, 0.1, and 0.5) demonstrated that the x_GMP = 0.01 formulation presents the highest enhancement in its dissolution. GMP went from being practically insoluble to reach 3.9 ± 0.9 μg/mL, and IBS showed a 12-fold increment with respect to the dissolution of its crystalline form. Infrared studies showed that the increase in the dissolution profile is related to the intermolecular interactions (hydrogen bonds), which were dependent of composition. Results of structural and thermal characterization performed by XRD and DSC showed that samples have remained in amorphous state for more than 10 months of storage. This work contributes to the development of a highly soluble co-amorphous drugs with potential used in the treatment of MetS.

Nanoparticulate-based drug delivery systems for small molecule anti-diabetic drugs: An emerging paradigm for effective therapy

Emergence of nanoparticulate drug delivery systems in diabetes has facilitated improved delivery of small molecule drugs which could dramatically improve the quality of life for diabetics. Conventional dosage forms of the anti-diabetic drugs exhibit variable/less bioavailability and short half-life, demanding frequent dosing and causing increased side-effects resulting in ineffectiveness of therapy and non-compliance with the patients. Considering the chronic nature of diabetes, nanotechnology-based approaches are more promising in terms of providing site-specific delivery of drugs with higher bioavailability and reduced dosage regimen. Nanomedicines act at the cellular and molecular levels to enhance the uptake of the drug into the cells or block the efflux mechanisms thus retaining the drug inside the cell for a longer duration of time. Many studies have hinted at the possibility of administering peptide drugs like glucagon like peptides orally by encapsulation into nanoparticles. Nanoparticles also allow further modifications including their encapsulation into microparticles, polyethylene glycol (PEG)-PEGylation- or functionalization with ligands for active targeting. Nevertheless, such remarkable benefits are fraught with their long-term safety concerns, regulatory hurdles, limitations of scale-up and ineffective patent protection which have hindered their commercialization. This review summarizes the latest advances in the area of nanoformulations as applied to the delivery of anti-diabetics. STATEMENT OF SIGNIFICANCE: The present work describes the latest advancements in the area of nanoformulations for anti-diabetic therapy along with highlighting the advantages that these nanoformulations offer at molecular level for diabetes. Although several potent orally active anti-hyperglycemic agents are available, the current challenges in efficient management of diabetes include optimization of the present therapies to ensure an optimum and stable level of glucose, and also to reduce the occurrence of long term complications associated with diabetes. Nanoformulations because of their high surface area to volume ratio provide improved efficacy, targeting their delivery to the desired site of action tends to minimize adverse effects and administration of peptide drugs by oral route is also possible by encapsulating them in nanoparticles. As we reflect on the success and failures of latest research on nanoformulations for the treatment of diabetes, it is important not to dwell on lack of FDA approvals but rather define future directions that guarantee more effective anti-diabetic treatment. In proposed review we have explored the latest advancement in anti-diabetic nanotechnology based formulations.

Glimepiride Administered in Chow Reversibly Impairs Glucose Tolerance in Mice

Sulfonylureas are a class of antidiabetes medications prescribed to millions of individuals worldwide. Rodents have been used extensively to study sulfonylureas in the laboratory. Here, we report the results of studies treating mice with a sulfonylurea (glimepiride) in order to understand how the drug affects glucose homeostasis and tolerance. We tested the effect of glimepiride on fasting blood glucose, glucose tolerance, and insulin secretion, using glimepiride sourced from a local pharmacy. We also examined the effect on glucagon, gluconeogenesis, and insulin sensitivity. Unexpectedly, glimepiride exposure in mice was associated with fasting hyperglycemia, glucose intolerance, and decreased insulin. There was no change in circulating glucagon levels or gluconeogenesis. The effect was dose-dependent, took effect by two weeks, and was reversed within three weeks after removal. Glimepiride elicited the same effects in all strains evaluated: four wild-type strains, as well as the transgenic Grn-/- and diabetic db/db mice. Our findings suggest that the use of glimepiride as a hypoglycemic agent in mice should proceed with caution and may have broader implications about mouse models as a proxy to study the human pharmacopeia.

A top-down technique to improve the solubility and bioavailability of aceclofenac: in vitro and in vivo studies

The aim of the present work was to tackle the solubility issue of a biopharmaceutics classification system (BCS)-II drug, aceclofenac. Although a number of attempts to increase the aqueous solubility have been made, none of the methods were taken up for scale-up. Hence size reduction technique by a top-down approach using wet milling process was utilized to improve the solubility and, consequently, the dissolution velocity of aceclofenac. The quality of the final product was ensured by Quality by Design approach wherein the effects of critical material attributes and critical process parameters were assessed on the critical quality attributes (CQAs) of nanocrystals. Box–Behnken design was applied to evaluate these effects on critical quality attributes. The optimized nanocrystals had a particle size of 484.7±54.12 nm with a polydispersity index (PDI) of 0.108±0.009. The solid state characterization of the formulation revealed that the crystalline nature of the drug was slightly reduced after the milling process. With the reduced particle size, the solubility of the nanocrystals was found to increase in both water and 0.1 N HCl when compared with that of unmilled pure aceclofenac. These results were further supported by in vitro release studies of nanocrystals where an appreciable dissolution velocity with 100.07%±2.38% release was observed for aceclofenac nanocrystals compared with 47.66%±4.53% release for pure unmilled aceclofenac at the end of 2 h. The in vivo pharmacokinetic data generated showed a statistically significant increase in the C_max for aceclofenac nanocrystals of 3.75±0.28 µg/mL (for pure unmilled aceclofenac C_max was 1.96±0.17 µg/mL). The results obtained indicated that the developed nanocrystals of aceclofenac were successful in improving the solubility, thus the absorption and bioavailability of the drug. Hence, it may be a viable and cost-effective alternative to the current therapy.