Enhanced oral bioavailability of isradipine via proniosomal systems

Development and Optimization of Proniosomal Formulation of Irbesartan Using a Box-Behnken Design to Enhance Oral Bioavailability: Physicochemical Characterization and In Vivo Assessment

This research work aimed to develop and evaluate proniosomes for the oral delivery of the lipophilic drug Irbesartan (IRB) to improve its solubility and bioavailability. Proniosomes of Irbesartan were formulated using a lipid, surfactant, and carrier by a slurry method. Based on the prepared preliminary trial batches and their evaluation, the formulation was optimized by employing a Box-Behnken design (BBD) in which concentrations of span 60 (X1), cholesterol (X2), and mannitol (X3) were used as three independent variables and the vesicular size (VS) (Y1), % entrapment efficiency (% EE) (Y2), and % cumulative drug release (% CDR) (Y3) were used as dependent variables. The optimized batch B1 was obtained from the BBD experiment after validation of checkpoint analysis, and their characterization was done for VS, % EE, % CDR, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) analysis. The optimized batch showed a VS of 199 ± 5.4 nm, a % EE of 99.25 ± 2.24%, and a % CDR of 97.36 ± 1.13% at 24 h. Scanning electron microscopy (SEM) study showed a smooth surface of batch B1. DSC and XRD studies indicated the amorphous nature of the proniosomal formulation. The proniosomal formulation showed increased solubility (2.65 ± 0.2 mg/mL) in phosphate buffer, pH 6.8, as compared to water (0.059 ± 0.02 mg/mL). The pharmacokinetic study in rats confirmed the increased bioavailability of the drug in optimized proniosomal formulation compared with its pure drug suspension. Cmax, Tmax, and AUC0-t of the drug also increased by 2-fold compared to those of drug suspension. Thus, in conclusion, the proniosomal formulation proved to be an efficient carrier for improved oral delivery of Irbesartan by improving the solubility and bioavailability of the drug.

Eco-friendly preparation, characterization, evaluation of anti-melanogenesis/antioxidant effect and in vitro/in vivo safety profile of kojic acid loaded niosome as skin lightener preparation

In the current study, an ultrasonic approach (as green method) was utilized to prepared kojic acid niosome (kojisome) which aimed to increase the dermal delivery and improving anti-melanogenesis properties. The study's findings demonstrated that increasing cholesterol enhanced the mean particle size from 68.333 ± 5.686 nm to 325.000 ± 15.099 nm and entrapment efficiency 0% to 39.341 ± 4.126% of the kojisome. Cholesterol may enhance the number and rigidity of bilayers that induced a size enhancement and entrapment efficiency. The skin permeability test revealed that kojisome gel had more kojic acid in dermal layers (437.563 ± 29.857 μg/cm2 or 16.624 ± 1.379%) than kojic acid plain gel (161.290 ± 14.812 μg/cm2 or 6.128 ± 0.672%). The niosome's lipophilicity allowed for gradual penetration, possibly due to better contact with the skin layers. Also, the extended-release behavior of improved kojisome exhibited high safety profile and low side effect in In vitro cytotoxicity assay, dermal irritation test, and Histo-pathological evaluation. Furthermore, optimum kojisome inhibited melanin formation (53.093 ± 2.985% at 1000 µM) higher than free kojic acid (62.383 ± 1.958%) significantly (p < 0.05). In addition, Kojisome 6 inhibited L-dopa auto-oxidation greater extent (94.806 ± 2.411%) than pure kojic acid solution (72.953 ± 2.728%). Kojisome by delivering and targeting large amount of kojic acid on specific site causes high efficacy in inhibition of melanin synthesis. The observations of this study revealed that the produced kojisome might be used as a potential nano-vehicle for kojic acid dermal administration, thereby opening up innovative options for the treatment of hyperpigmentation problems.

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.

Cholesterol-Based Nanovesicles Enhance the In Vitro Cytotoxicity, Ex Vivo Intestinal Absorption, and In Vivo Bioavailability of Flutamide

Critical adverse effects and frequent administration, three times per day, limit the use of flutamide (FLT) as a chemotherapeutic agent in the treatment of prostate cancer. Therefore, our research aimed to develop new cholesterol-based nanovesicles for delivering FLT to malignant cells in an endeavor to maximize its therapeutic efficacy and minimize undesired adverse effects. Draper–Lin small composite design was used to optimize the critical quality attributes of FLT-loaded niosomes and ensure the desired product quality. The influence of the selected four independent variables on mean particle size (Y₁), zeta potential (Y₂), drug entrapment efficiency (Y₃), and the cumulative drug release after 24 h (Y₄) was examined. The optimized nanovesicles were assessed for their in vitro cytotoxicity, ex-vivo absorption via freshly excised rabbit intestine as well as in vivo pharmacokinetics on male rats. TEM confirmed nanovescicles’ spherical shape with bilayer structure. Values of dependent variables were 748.6 nm, −48.60 mV, 72.8% and 72.2% for Y₁, Y₂, Y₃ and Y₄, respectively. The optimized FLT-loaded niosomes exerted high cytotoxic efficacy against human prostate cancer cell line (PC-3) with an IC₅₀ value of 0.64 ± 0.04 µg/mL whilst, it was 1.88 ± 0.16 µg/mL for free FLT. Moreover, the IC₅₀ values on breast cancer cell line (MCF-7) were 0.27 ± 0.07 µg/mL and 4.07 ± 0.74 µg/mL for FLT-loaded niosomes and free FLT, respectively. The permeation of the optimized FLT-loaded niosomes through the rabbit intestine showed an enhancement ratio of about 1.5 times that of the free FLT suspension. In vivo pharmacokinetic study displayed an improvement in oral bioavailability of the optimized niosomal formulation with AUC and C_max values of 741.583 ± 33.557 μg/mL × min and 6.950 ± 0.45 μg/mL compared to 364.536 ± 45.215 μg/mL × min and 2.650 ± 0.55 μg/mL for the oral FLT suspension. With these promising findings, we conclude that encapsulation of FLT in cholesterol-loaded nanovesicles enhanced its anticancer activity and oral bioavailability which endorse its use in the management of prostate cancer.

Just add water: hydratable, morphologically diverse nanocarrier powders for targeted delivery

Two major obstacles that limit the widespread usage of polymeric nanocarriers include the complexity of formulation methods and their stability during storage. To address both of these issues, here we present morphologically complex nanocarriers in a hydratable powder form, which bypasses the need for expensive, harsh, and/or time-consuming nanocarrier fabrication techniques. The powders are composed of carbohydrates and self-assembling polymer amphiphiles having a low glass transition temperature. Hydration requires less than one minute and only involves the addition of aqueous media (water or saline) to rapidly obtain self-assembled micelles, worm-like micelles (i.e. filomicelles), or polymersomes from poly(ethylene glycol)-b-poly(propylene sulfide) (PEG-b-PPS) polymers. The formulated powders are highly stable, achieving hydration into monodisperse nanocarriers following >6 months of storage. Diverse drug cargoes were efficiently encapsulated during hydration, including hydrophobic small molecules for micellar morphologies, as well as individual and concurrent loading of both hydrophobic and hydrophilic molecules for vesicular morphologies. Hydrated polymersomes are shown to load hydrophilic biological macromolecules, and encapsulated enzymes retain bioactivity. Furthermore, we demonstrate that inclusion of lipid-anchored ligands in powder form permits the surface-display of targeting ligands and enhances target cell uptake, thereby extending this technology to targeted drug delivery applications. Our powder-based formulation strategy was extendable to commercially available polymer amphiphiles, including PEG-b-polystyrene and PEG-b-polycaprolactone. The formulated nanotechnologies described herein are highly modular, require minimal preparation, and remain stable in ambient long-term storage (bypassing cold chain requirements), which will enable their use in medicine (human and veterinary), research, and commercial applications from cosmetics to agriculture.

Quality by Design for the Development and Analysis of Enhanced In-Situ Forming Vesicles for the Improvement of the Bioavailability of Fexofenadine HCl in Vitro and in Vivo

Drug absorption from the gastrointestinal tract (GIT) is one of the major problems affecting the bioavailability of orally absorbed drugs. This work aims to enhance Fexofenadine HCl oral bioavailability in vivo, the drug used for allergic rhinitis. In this study, novel spray-dried lactose-based enhanced in situ forming vesicles were prepared using different absorption enhancer by the slurry method. Full factorial design was used to obtain an optimized formulation, while central composite design was used to develop economic, environment-friendly analysis method of Fexofenadine HCl in plasma of rabbits. The optimized formulation containing Capryol 90 as absorption enhancer has a mean particle size 202.6 ± 3.9 nm and zeta potential -31.6 ± 0.9 mV. It achieved high entrapment efficiency of the drug 73.7 ± 1.7% and rapid Q3h release reaches 71.5 ± 2.7%. The design-optimized HPLC assay method in rabbit plasma could separate Fexofenadine HCl from endogenous plasma compounds in less than 3.7 min. The pharmacokinetic study and the pharmacological effect of the fexofenadine-loaded optimized formulation showed a significant increase in blood concentration and significantly higher activity against compound 48/80 induced systemic anaphylaxis-like reactions in mice. Therefore, enhanced in situ forming vesicles were effective nanocarriers for the entrapment and delivery of Fexofenadine HCl.

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.

Optimization of Aceclofenac Proniosomes by Using Different Carriers, Part 1: Development and Characterization

In the contemporary medical model world, the proniosomal system has been serving as a new drug delivery system that is considered to significantly enhance the bioavailability of drugs with low water solubility. The application of this system can improve the bioavailability of aceclofenac that is used for the relief of pain and inflammation in osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis. The present study is intended to develop an optimized proniosomal aceclofenac formula by the use of different carriers. Aceclofenac proniosomes have been prepared by slurry method, and different carriers such as maltodextrin, mannitol, and glucose were tried. Prepared proniosomes characterized by differential scanning calorimetry (DSC) analysis and Fourier transform infrared (FTIR) analysis revealed the compatibility of the drug chosen with the ingredient added, powder X-ray diffractometry (XRD) confirmed the amorphous phase of the prepared proniosomes, and finally, the surfactant layer was observed by scanning electron microscopy (SEM). Aceclofenac physical state transformations were confirmed with all formulas but maltodextrin proniosomes exhibited solubility more than other formulations. HPLC method has been used to analyze the niosomes derived from proniosomes in terms of their entrapment capability and drug content. The obtained results revealed that aceclofenac proniosomes can be successfully prepared by using different carriers.

Development and evaluation of isradipine via rutin-loaded coated solid-lipid nanoparticles

The objective was to develop a stable and non-compliance coated solid-lipid nanoparticles (coated SLN) using polymer (Eudragit L100) and lipoid (glycerol monostearate: soya lecithin) for partial dose reduction of isradipine [ISR; 2.5 mg by combination of bioenhancing agent (rutin; Ru) in equivalent ratio]. The physicochemical characterizations were performed by FT-IR and DSC of elected model drug (ISR), drug mixer with Ru/polymer and coated SLN with Ru (ONbp); the resulted distinctive peaks demonstrated that no chemical interaction and incompatibility found between them. The plasma samples of formulation (ONbp) were analyzed by liquid chromatography (HPLC) using UV-spectrometer. Data were integrated and analyzed with the help of a computer-designed program "Kinetica Software" (Thermo Scientific Kinetica, PK/PD Analysis, version 5.0, Philadelphia, PA). The pharmacokinetic study showed 3.2- to 4.7-folds enhancement in oral bioavailability of coated SLN of ISR with Ru (ONbp) when compared to a coated formulation of ISR without Ru (ONps) and conventional drug suspension. In vivo studies were revealed significantly at greater extent in (drug stability and solubility) oral absorption, which has shown potential entrapment efficiency (97.85% ± 1.02%) to improve biological activity against hypertension. Hence, nano-system of ISR against hypertension is achieved with consequent dose reduction with enhanced systemic bioavailability.

Proniosomes derived niosomes: recent advancements in drug delivery and targeting

Vesicular drug delivery systems have gained wide attention in the field of nanotechnology. Among them proniosomes become the superior over other vesicular carriers. Proniosomes are dry formulations of water soluble nonionic surfactant coated carrier system which immediately forms niosomes upon hydration. They have the capability to overcome the instability problems associated with niosomes and liposomes and have the potential to improve solubility, bioavailability, and absorption of various drugs. Furthermore, they offer versatile drug delivery concept for enormous number of hydrophilic and hydrophobic drugs. They have the potential to deliver drugs effectively through different routes at specific site of action to achieve controlled release action and reduce toxic effects associated with drugs. This review discusses the general preparation techniques of proniosomes and mainly focus on the applications of proniosomes in drug delivery and targeting. Moreover, this review demonstrates critical appraisal of the literature for proniosomes. Additionally, this review extensively explains the potential of proniosomes in delivering drugs via different routes, such as oral, parenteral, dermal and transdermal, ocular, oral mucosal, vaginal, pulmonary, and intranasal. Finally, the comparison of proniosomes with niosomes manifests the clear distinction between them. Moreover, proniosomes need to be explored for proteins and peptide delivery and in the field of nutraceuticals and develop pilot plant scale up studies to investigate them in industrial set up.

Technology overview and drug delivery application of proniosome

Rapid advancement in the field of colloidal science has shown a great progress in the development of proniosome technology (PT) as an impending drug delivery system. PT is a valuable carrier system for delivery of hydrophobic as well as hydrophilic drugs. It is a liquid crystalline compact niosomal hybrid, which upon hydration gives niosomes. They can augment the bioavailability of encapsulated drug and provide better therapeutic activity in a controlled manner. Non-toxicity, penetration enhancing the effect of surfactant and modified drug release from the proniosomal transdermal gel has attracted a greater attention of formulation scientist toward PT. Free flowing dry proniosomal powder are suitable for unit dosage forms such as tablet and capsules. Proniosomes are auspicious drug delivery system for the future. Proniosomes-derived niosomes are a better alternative to the other vesicular system due to their superior physicochemical stability and effective drug delivery capability. The focus of this review is to bring out all the aspects of proniosomes including their different compositions, various methods of preparation, characterization and recent development in their therapeutic applications.

Potentials of proniosomes for improving the oral bioavailability of poorly water-soluble drugs

Abstract Objective: The objectives of this study were, first, to develop a free-flowing and stable proniosome formulation for poorly water-soluble drugs such as vinpocetine; and second, to estimate its bioavailability as oral drug delivery system.

METHODS

The proniosomes consisting of span60, cholesterol, sorbitol and vinpocetine were prepared by a novel approach. After the proniosomes were contacted with water, the suspension of vinpocetine-loaded niosomes formed automatically. The proniosomes and reconstituted niosomes were evaluated for their physicochemical characteristics, in vitro drug dissolution and release, integrity and stability at different GI tract pH conditions, in situ single-pass intestinal perfusion and in vivo bioavailability.

RESULTS

The proniosome powder exhibited excellent flowability. The reconstituted niosomes with high drug entrapment efficiency (89.67 ± 3.28%) showed spherical morphology with smooth surface under transmission electron microscope (TEM). X-ray diffraction (XRD) indicated that the drug was in an amorphous or molecular state in proniosome powder. In vitro dissolution and release study, proniosomes did enhance the dissolution and release rate compared to vinpocetine suspension in phosphate buffer solution (pH 7.2). Proniosome-derived niosomes could keep their integrity and stability at different GI tract pH conditions. The in situ single-pass intestinal perfusion indicated that encapsulation of vinpocetine into niosomes could largely improved the absorption of vinpocetine. The AUC(0-∞) of F2 and F3 was about 4.0- and 4.9-fold higher than that of the vinpocetine suspension, respectively. The results demonstrated the proniosomes indeed remarkably enhanced the oral bioavailability of vinpocetine.

CONCLUSION

This study suggested the potential of proniosomes as stable precursors for the immediate preparation of niosome carrier systems.