Development and in vitro/in vivo evaluation of controlled release provesicles of a nateglinide-maltodextrin complex

Water in nigella oil microemulsion for enhanced oral bioavailability of linagliptin

Linagliptin is hydrophilic antidiabetic with poor oral bioavailability due to poor permeability and pre-systemic metabolism. The objective was to assess w/o microemulsion for enhanced oral bioavailability of linagliptin. Nigella oil was used as oily phase based on its reported antidiabetic effect. Isopropyl myristate (IPM) or capryol were combined with nigella oil to impart intestinal membrane permeabilizing abilities. Pseudoternary phase diagrams were constructed utilizing nigella oil in presence and absence of isopropyl myristate or capryol as oily phase using Tween 60 as surfactant. W/O microemulsion formulations were selected from the constructed phase diagrams and linagliptin was loaded in the internal aqueous phase at a concentration of 0.5 mg/ml. The prepared formulations were physically evaluated and linagliptin in vitro release was monitored. Eventually, the in vivo hypoglycemic effect was assessed using diabetic rats. The developed microemulsions were of w/o type and exhibited Newtonian flow behavior with nigella/capryol microemulsion recording the lowest viscosity. The recorded droplet size values were 104.9, 121.2 and 86.4 nm for nigella, nigella/IPM and nigella/capryol microemulsions, respectively. All microemulsion formulations showed slower drug release rate compared with aqueous suspension with nigella/capryol microemulsion showing the highest release rate compared to other microemulsions. Release data from microemulsion best fitted to Higuchi model. In vivo oral hypoglycemic activity measurement reflected a more intensified hypoglycemic effect with rapid onset after oral ingestion of microemulsion compared to linagliptin dispersion. Nigella oil/IPM-based microemulsion was ranked as the most effective. The investigation highlighted the feasibility of w/o microemulsion for enhanced oral bioavailability of hydrophilic drugs like linagliptin.

Optimized mucoadhesive niosomal carriers for intranasal delivery of carvedilol: A quality by design approach

Carvedilol (CV), a β-blocker essential for treating cardiovascular diseases, faces bioavailability challenges due to poor water solubility and first-pass metabolism. This study developed and optimized chitosan (CS)-coated niosomes loaded with CV (CS/CV-NS) for intranasal (IN) delivery, aiming to enhance systemic bioavailability. Utilizing a Quality-by-Design (QbD) approach, the study investigated the effects of formulation variables, such as surfactant type, surfactant-to-cholesterol (CHOL) ratio, and CS concentration, on CS/CV-NS properties. The focus was to optimize specific characteristics including particle size (PS), polydispersity index (PDI), zeta potential (ZP), entrapment efficiency (EE%), and mucin binding efficiency (MBE%). The optimal formulation (Opt CS/CV-NS), achieved with a surfactant: CHOL ratio of 0.918 and a CS concentration of 0.062 g/100 mL, using Span 60 as the surfactant, exhibited a PS of 305 nm, PDI of 0.36, ZP of + 33 mV, EE% of 63 %, and MBE% of 57 %. Opt CS/CV-NS was characterized for its morphological and physicochemical properties, evaluated for stability under different storage conditions, and assessed for in vitro drug release profile. Opt CS/CV-NS demonstrated a 1.7-fold and 4.8-fold increase in in vitro CV release after 24 h, compared to uncoated CV-loaded niosomes (Opt CV-NS) and free CV, respectively. In vivo pharmacokinetic (PK) study, using a rat model, demonstrated that Opt CS/CV-NS achieved faster Tmax and higher Cmax compared to free CV suspension indicating enhanced absorption rate. Additionally, Opt CV-NS showed a 1.68-fold higher bioavailability compared to the control. These results underscore the potential of niosomal formulations in enhancing IN delivery of CV, offering an effective strategy for improving drug bioavailability and therapeutic efficacy.

Tocopherol succinate-loaded ethosomal gel synthesized by cold method technique: Deeper biophysical characterizations for translational application on human skin

BACKGROUND

Tocopherols are well-known antioxidant and moisturizing agent. Tocopherol succinate (TS) are widely used in many skin products especially used in anti-aging and skin whitening product formulation.

AIM

We previously reported the successful synthesis and preliminary characterizations of stable TS ethosomal gels (TSEG) (DOI: 10.1111/jocd.14907). Herein, we develop and further characterize TSEG to enhance the stability of the developed formulation with increased permeation through skin.

METHODS

Cold method technique was used to prepare TS ethosomes. The developed ethosomal vesicle size was 250 nm, which allowed TS to penetrate through the stratum corneum layer and act on melanocytes. For stability study was assessed by thermogravimetric analysis (TGA) by placing TSEG and unloaded/control ethosomal gel (CEG) at various temperature conditions, that is, 8°C, 25°C, 40°C, and 40°C ± 75% RH for 3 months. Organoleptic evaluation was done in terms of color, odor, and phase separation. Transmission electron microscopy (TEM), Fourier Transform infrared spectroscopy (FTIR), x-ray diffraction spectroscopy (XRD), zeta potential (ZP) and particle size (PS) was used for TSEG physical characterizations. In vitro dissolution and ex-vivo permeation studies (using Franz diffusion cell) were performed for both TSEG and CEG formulations. Human women (N = 34) were used to evaluate in vivo biophysical parameters including erythema, melanin, moisture content, sebum level, and skin elasticity.

RESULTS

Developed formulation was highly thermostable during the 3 months. Erythema, melanin, and sebum level decreased while marked improvement (p < 0.05) in moisture content and elasticity have been observed for the developed TSEG.

CONCLUSION

The developed TSEG formulation was found to be efficient, safe (no adverse effects observed), stable (at least for 3 months), and easy to use for topical application with improved skin complexation and skin integrity.

PEGylated Tween 80-functionalized chitosan-lipidic nano-vesicular hybrids for heightening nose-to-brain delivery and bioavailability of metoclopramide

A PEGylated Tween 80-functionalized chitosan-lipidic (PEG-T-Chito-Lip) nano-vesicular hybrid was developed for intranasal administration as an alternative delivery route to help improve the poor oral bioavailability of BCS class-III model/antiemetic (metoclopramide hydrochloride; MTC). The influence of varying levels of chitosan, cholesterol, PEG 600, and Tween 80 on the stability/release parameters of the formulated nanovesicles was optimized using Draper-Lin Design. Two optimized formulations (Opti-Max and Opti-Min) with both maximized and minimized MTC-release goals, were predicted, characterized, and proved their vesicular outline via light/electron microscopy, along with the mutual prompt/extended in-vitro release patterns. The dual-optimized MTC-loaded PEG-T-Chito-Lip nanovesicles were loaded in intranasal in-situ gel (ISG) and further underwent in-vivo pharmacokinetics/nose-to-brain delivery valuation on Sprague-Dawley rats. The absorption profiles in plasma (plasma-AUC_0-∞) of the intranasal dual-optimized MTC-loaded nano-vesicular ISG formulation in pretreated rats were 2.95-fold and 1.64-fold more than rats pretreated with orally administered MTC and intranasally administered raw MTC-loaded ISG formulation, respectively. Interestingly, the brain-AUC_0-∞ of the intranasal dual-optimized MTC-loaded ISG was 10 and 3 times more than brain-AUC_0-∞ of the MTC-oral tablet and the intranasal raw MTC-loaded ISG, respectively. It was also revealed that the intranasal dual-optimized ISG significantly had the lowest liver-AUC_0-∞ (862.19 ng.g^-1.h^-1) versus the MTC-oral tablet (5732.17 ng.g^-1.h^-1) and the intranasal raw MTC-loaded ISG (1799.69 ng.g^-1.h^-1). The brain/blood ratio profile for the intranasal dual-optimized ISG was significantly enhanced over all other MTC formulations (P < 0.05). Moreover, the 198.55% drug targeting efficiency, 75.26% nose-to-brain direct transport percentage, and 4.06 drug targeting index of the dual-optimized formulation were significantly higher than those of the raw MTC-loaded ISG formulation. The performance of the dual-optimized PEG-T-Chito-Lip nano-vesicular hybrids for intranasal administration evidenced MTC-improved bioavailability, circumvented hepatic metabolism, and enhanced brain targetability, with increased potentiality in heightening the convenience and compliance for patients.

Formulation of tizanidine hydrochloride-loaded provesicular system for improved oral delivery and therapeutic activity employing a 23 full factorial design

Tizanidine hydrochloride (TZN) is one of the most effective centrally acting skeletal muscle relaxants. The objective of this study is to prepare TZN-loaded proniosomes (TZN-PN) aiming at enhanced oral delivery and therapeutic activity. TZN-PN were prepared by coacervation phase separation method. The developed vesicles were characterized via entrapment efficiency percentage (EE%), vesicular size (VS), and zeta potential (ZP). A 2³ full factorial design was employed to attain an optimized TZN-PN formulation. The optimized TZN-PN were further characterized via in vitro release study and transmission electron microscopy (TEM). In vivo rotarod test was employed for determination of the muscle relaxant activities of rats and levels of GABA and EAAT2 were detected. The developed TZN-PN exhibited relatively high EE% (75.78-85.45%), a VS ranging between (348-559 nm), and a ZP (-26.47 to -59.64). In vitro release profiles revealed sustained release of TZN from the optimized TZN-PN, compared to free drug up to 24 h. In vivo rotarod study revealed that the elevation in coordination was in the following order: normal control < free TZN < market product < TZN-PN (F6). Moreover, the optimized TZN-PN exhibited significant elevated coordination activity by 39% and 26% compared to control group and market product group, respectively. This was accompanied with an elevation in both GABA and EAAT2 serum levels. Thus, it could be concluded that encapsulation of TZN in the provesicular nanosystem proniosomes has enhanced the anti-nociceptive effect of the drug and consequently its therapeutic activity.

Ultra-stable dextran conjugated prodrug micelles for oxidative stress and glycometabolic abnormality combination treatment of Alzheimer's disease

Sophisticated nanomedicines are continually being developed, but big obstacles remain before they finish the drug release mission. The first challenge is rupture possibility of structure when infinite dilution, competitive reaction of electrolytes and protein in blood circulation. In addition, low responsive drug release efficiency in the lesion site remains the major challenge for clinical application of nanomedicine combination treatment. In this study, we discussed the opportunities for Alzheimer's disease (AD) combination therapy based on the thermodynamically ultra-stable dextran conjugated prodrug micelles. Dextran-nateglinide conjugated prodrug micelles (NA) and dextran-vitamin E succinate conjugated prodrug micelles (VES) presented ultra-low critical micelle concentration of ~10^-5 mM and high physiological stability when challenged by NaCl, sodium dodecyl sulphate (SDS), dodecyl dimethyl benzyl ammonium chloride (DDBAC) and no rupture of structure happened. The NA/insulin polymer-drug conjugate micelles (NA/INS PDC) and VES/insulin polymer-drug conjugate micelles (VES/INS PDC) efficiently cleaved by reactive oxygen species (ROS), leading to over 80% release of the encapsulated and conjugated drugs. The combination of nateglinide and insulin, vitamin E succinate and insulin improved the glucose metabolism, reduced oxidative stress, improved the mitochondrial function and recovered the cognitive capacity of mice. This work demonstrated a paradigm for specific and high efficacy AD combination therapy.

Analysis of topical dosing and administration effects on ocular drug delivery in a human eyeball model using computational fluid dynamics

Predicting the spatial and temporal drug concentration distributions in the eyes is essential for quantitative analysis of the therapeutic effect and overdose issue via different topical administration strategies. To address such needs, an experimentally validated computational fluid dynamics (CFD) based virtual human eye model with physiologically realistic multiple ophthalmic compartments was developed to study the effect of administration frequency and interval on drug concentration distributions. Timolol was selected as the topical dosing drug for the numerical investigation of how administration strategy can influence drug transport and concentration distribution over time in the human eye. Administration frequencies employed in this study are 1-4 times per day, and the administration time intervals are Δt = 900 s, 1800 s, and 3600 s. Numerical results indicate that the administration frequency can significantly affect the temporal timolol concentration distributions in the ophthalmic compartments. More administrations per day can prolong the mediations at relatively high levels in all compartments. CFD simulation results also show that shorter administration intervals can help the medication maintain a relatively higher concentration during the initial hours. Longer administration intervals can provide a more stable medication concentration during the entire dosing time. Furthermore, numerical parametric analysis in this study indicates that the elimination rate in the aqueous humor plays a dominant role in affecting the drug concentrations in multiple ophthalmic compartments. However, it still needs additional clinical data to identify how much drugs can be transported into the cardiac and/or respiratory systems via blood circulation for side effect assessment.

Fluticasone propionate-loaded solid lipid nanoparticles with augmented anti-inflammatory activity: optimisation, characterisation and pharmacodynamic evaluation on rats

This work aimed to elaborate an optimised fluticasone propionate (FP)-loaded solid lipid nanoparticles (SLNs) to enhance FP effectiveness for topical inflammatory remediation. The influences of drug amount, lipid, and surfactant ratios, on drug release pattern and stability were investigated utilising Box-Behnken design. Elaboration, characterisation, and pharmacodynamic evaluation in comparison with the marketed formulation (Cutivate® cream, 0.05%w/w FP), were conducted for the optimised SLNs. The optimised SLNs with a size of 248.3 ± 1.89 nm (PDI = 0.275) and -32.4 ± 2.85 mV zeta potential were evidenced good stability physiognomies. The optimised SLNs pre-treated rats exhibited non-significant difference in paw volume from that of the control group and showed a significant reduction in both PGE₂ and TNF-α levels by 51.5 and 61%, respectively, in comparison with the Carrageenan group. The optimised FP-loaded SLNs maximised the efficacy of FP towards inflammation alleviation that increase its potential as efficient implement in inflammatory skin diseases remediation.

Proniosomal Telmisartan Tablets: Formulation, in vitro Evaluation and in vivo Comparative Pharmacokinetic Study in Rabbits

Objective

The purpose of this study was to prepare proniosomal vesicles of Telmisartan (TEL) to be compressed into tablets which will be further evaluated in vitro and in vivo.

Materials and Methods

An experimental design was adopted using surfactants of different HLB values (span 40-brij 35), different cholesterol ratios (20–50%) and different phospholipid types (egg yolk-soyabean). Different responses were measured followed by tablet manufacturing. The highest EE was shown in F3 (85%) while the lowest value was obtained in F7 (8.4%). Finally, zeta potential results were in the range of −0.67 to −27.6 mv. Compressibility percent revealed that F5 showed an excellent flowability characteristic with a value of 9.74±1.61 while F3 and F6 showed good flowability characteristics. By the end of the release, F6 showed approximately 90% drug release.

Results

F6 was selected for the in vivo study; C_max was increased by 1.5-fold while AUC_0-∞ also increased significantly by 3-fold when compared with commercial tablet and finally, t_max was increased by 3-fold indicating sustained release pattern. The relative bioavailability was also increased by 3.2-fold.

Conclusion

The results of this study suggested that the formulation of compressed tablets containing more stable proniosomal powder extended the release of TEL and increased its bioavailability as well.

Formulation Development and Evaluation of Novel Vesicular Carrier for Enhancement of Bioavailability of Poorly Soluble Drug

BACKGROUND

Niosomes are a vesicular carrier system comprised of a Nonionic surfactant bilayer surrounding an aqueous compartment. Niosomes are presumed to raise the intake of the poorly water-soluble drugs by M cells of Peyer's patches present in the intestine's lymphatic tissues, thereby avoiding the first-pass metabolism and increasing its oral bioavailability. Biodegradability, nonimmunogenic nature, minimal side effects, low cost, good stability, and flexibility to incorporate hydrophilic and lipophilic drugs are other advantages of niosomes.

OBJECTIVE

To formulate and evaluate a novel vesicular carrier system of a poorly soluble drug Lurasidone hydrochloride for the enhancement of its solubility and bioavailability.

METHODS

The thin-film hydration technique used to prepare Lurasidone hydrochloride loaded niosomes using different grades of nonionic surfactants like Brij, Span, and Tween. They evaluated for particle size, zeta potential, percent entrapment efficiency, in-vitro drug release, and in-vivo study.

RESULTS

Niosomes comprised of Brij S-100 in drug: cholesterol: surfactant (1:1:1) showed particle size (1.15 ± 0.21 μm) and percent entrapment efficiency (97.02 ± 0.21%) and was selected for further studies. Various pharmacokinetic parameters like C_max (281.27ng/ml), T_max (5 h), and AUC (2640.197) were found to be significantly improved compared to plain drug solution.

CONCLUSION

The Niosomal formulation could be the promising drug delivery system for the controlled and sustained release of Lurasidone.

Nanoformulation strategies for improving intestinal permeability of drugs: A more precise look at permeability assessment methods and pharmacokinetic properties changes

The therapeutic efficacy of orally administered drugs is often restricted by their inherent limited oral bioavailability. Low water solubility, limited permeability through the intestinal barrier, instability in harsh environment of the gastrointestinal (GI) tract and being substrate of the efflux pumps and the cytochrome P450 (CYP) can impair oral drug bioavailability resulting in erratic and variable plasma drug profile. As more drugs with low membrane permeability are developed, new interest is growing to enhance their intestinal permeability and bioavailability. A wide variety of nanosystems have been developed to improve drug transport and absorption. Sufficient evidence exists to suggest that nanoparticles are able to increase the transepithelial transport of drug molecules. However, key questions remained unanswered. What types of nanoparticles are more efficient? What are preclinical (or clinical) achievements of each type of nanoformulation in terms of pharmacokinetic (PK) parameters? Addressing this issue in this paper, we have reviewed the current literature regarding permeability enhancement, permeability assessment methods and changes in PK parameters following administration of various nanoformulations. Although permeability enhancement by various nanoformulations holds great promise for oral drug delivery, many challenges still need to be addressed before development of more clinically successful nanoproducts.

Cubosomal based oral tablet for controlled drug delivery of telmisartan: formulation, in-vitro evaluation and in-vivo comparative pharmacokinetic study in rabbits

A nanoparticulate system; cubosomes has been suggested to support the controlled release of Telmisartan (TEL), a poorly water-soluble medication. Four distinctive formulae were selected according to the results of three estimated responses. The liquid cubosomes were successfully adsorbed onto Aerosil 380 to form granules. The formulae were evaluated for their flow properties. The best granules were compressed into tablets suitable for oral administration. The tablets were evaluated for its performance. The in vivo study of the best selected cubosomal tablets was checked after oral administration in the blood of albino rabbits utilizing an HPLC method. Results revealed that the highest EE was shown in formulae C5 (59.68 ± 1.3). All the prepared formulae had particle size less than 500 nm with PDI < 0.5 and the highest zeta potential results were observed in C5, C7, C9, C11 and C12 (>30 mv). A7 and A9 prepared using Aerosil 380 showed a perfect flowability. After 1 h of dissolution testing, the commercial product showed a 66% drug release while the release of all cubosomal formulae didn't exceed 35% during the first hour reaching a 85% of the drug released at the end of 24 h. A7 was selected for the in vivo study; T_max of TEL absorption is increased for cubosomal formula by three folds indicating sustained release pattern. The relative bioavailability is also increased by 2.6 fold. The investigation proposed the rationality of cubosome to figure an effective controlled release tablets to improve its bioavailability and expand its activity.

Enhancement of Dissolution and Skin Permeability of Pentazocine by Proniosomes and Niosomal Gel

Proniosomes (PN) are the dry water-soluble carrier systems that may enhance the oral bioavailability, stability, and topical permeability of therapeutic agents. The low solubility and low oral bioavailability due to extensive first pass metabolism make Pentazocine as an ideal candidate for oral and topical sustained release delivery. The present study was aimed to formulate the PNs by quick slurry method that are converted to niosomes (liquid dispersion) by hydration, and subsequently formulated to semisolid niosomal gel. The PNs were found in spherical shape in the SEM and stable in the physicochemical and thermal analysis (FTIR, TGA, and XRD). The quick slurry method produced high recovery (> 80% yield) and better flow properties (θ = 28.1-37.4°). After hydration, the niosomes exhibited desirable entrapment efficiency (44.45-76.23%), size (4.98-21.3 μm), and zeta potential (- 9.81 to - 21.53 mV). The in vitro drug release (T_100%) was extended to more than three half-lives (2-4 h) and showed good fit to Fickian diffusion indicated by Korsmeyer-Peppas model (n = 0.136-0.365 and R² = 0.9747-0.9954). The permeation of niosomal gel was significantly enhanced across rabbit skin compared to the pure drug-derived gel. Therefore, the PNs are found promising candidates for oral as dissolution enhancement and sustained release for oral and topical delivery of pentazocine for the management of cancer pain.

Enhancing the Therapeutic Efficacy of Tamoxifen Citrate Loaded Span-Based Nano-Vesicles on Human Breast Adenocarcinoma Cells

Serious adverse effects and low selectivity to cancer cells are the main obstacles of long term therapy with Tamoxifen (Tmx). This study aimed to develop Tmx-loaded span-based nano-vesicles for delivery to malignant tissues with maximum efficacy. The effect of three variables on vesicle size (Y₁), zeta potential (Y₂), entrapment efficiency (Y₃) and the cumulative percent release after 24 h (Y₄) were optimized using Box-Behnken design. The optimized formula was prepared and tested for its stability in different storage conditions. The observed values for the optimized formula were 310.2 nm, - 42.09 mV, 75.45 and 71.70% for Y₁, Y₂, Y₃, and Y₄, respectively. The examination using electron microscopy confirmed the formation of rounded vesicles with distinctive bilayer structure. Moreover, the cytotoxic activity of the optimized formula on both breast cancer cells (MCF-7) and normal cells (BHK) showed enhanced selectivity (9.4 folds) on cancerous cells with IC₅₀ values 4.7 ± 1.5 and 44.3 ± 1.3 μg/ml on cancer and normal cells, respectively. While, free Tmx exhibited lower selectivity (2.5 folds) than optimized nano-vesicles on cancer cells with IC₅₀ values of 9.0 ± 1.1 μg/ml and 22.5 ± 5.3 μg/ml on MCF-7 and BHK cells, respectively. The promising prepared vesicular system, with greater efficacy and selectivity, provides a marvelous tool to overcome breast cancer treatment challenges.

Improving Properties of Albendazole Desmotropes by Supramolecular Systems with Maltodextrin and Glutamic Acid

Albendazole, an effective broad-spectrum anthelmintic agent, showed unpredictable therapeutic response caused by poor water solubility and slow dissolution rate. Then, novel binary and multicomponent supramolecular systems of two different solid forms of albendazole (I and II) with maltodextrin alone or with glutamic acid were studied as an alternative to improve the oral bioavailability of albendazole. The interactions and effects on the properties of albendazole were studied in solution and solid state. The solid systems were characterized using Raman and Fourier transform-infrared spectroscopy, thermal analysis, powder X-ray diffraction, and scanning electron microscopy. The solubility measurements, performed in aqueous and simulated gastric fluid, showed that albendazole (form II) was the most soluble form, while its supramolecular systems showed the highest solubility in simulated gastric fluid. On the other hand, the dissolution profiles of binary and multicomponent systems in simulated gastric fluid displayed pronounced increments of the dissolved drug and a faster dissolution rate compared to those of free albendazole forms. Thus, these supramolecular structures constitute an interesting alternative to improve the physicochemical properties of albendazole, with potential application for the preparation of pharmaceutical oral formulations.