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

Potential Use of Common Administration of Emulsion for Parenteral Nutrition and Vinpocetine: Compatibility Study and Prospect

Vinpocetine (VP) is distributed after oral and intravenous administration, and its uptake in the thalamus, basal ganglia, and visual cortex. Due to poor bioavailability (~7%) and marked first-pass effect (~75%), including a short half-life (2-3 h), oral administration of VP is limited. It requires frequent administration of the drug to obtain a therapeutic effect. Attempts to overcome these difficulties include the use of new drug delivery systems and/or alternative routes of drug administration. One possibility is the common administration of lipid emulsion and drug using the same catheter. However, this procedure is not recommended due to potential interaction and lack of safety data. For this purpose, we checked the compatibility of VP solutions with eight commercially available parenteral nutrition admixtures, i.e., Lipoflex special, Omegaflex special, Lipoflex peri, Omegaflex peri, Kabiven, SmofKabiven, Kabiven Peripheral, and Olimel Peri N4E. Coadministration is only possible if the stability of the drug and the lipid emulsion is confirmed. The available data are scarce and only concern the incompatibility of VP with ibuprofen. Compatibility tests were carried out in simulated administration through a Y-site connector using clinical flow rates. The stability of the drug and lipid emulsion was assessed by visual inspection and measurement of pH, osmolality, particle size as mean droplet diameter (MDD) and percentage of lipids residing in globules larger than 5 µm (PFAT5), zeta potential, polydispersity index, and lipid-free parenteral nutrition admixture(PNA) turbidity. The results of the compatibility of VP with eight commercial PN admixtures showed that all lipid emulsions show different signs of destabilization. In the studied samples, particles larger than 1000 nm, a significant increase in MDD, zeta potential, and loss of homogeneity visible as an increase in the polydispersity index were observed. Most of the samples had PFAT5 above the USP limit (0.05%). Taking into account the obtained data, VP should not be administered with the studied lipid emulsions for parenteral nutrition.

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.

Formulation of Glibenclamide proniosomes for oral administration: Pharmaceutical and pharmacodynamics evaluation

Glibenclamide (GB), oral antidiabetic sulfonylurea, is used in the management of diabetes mellitus type II. It suffers from low bioavailability due to low water solubility. This work aimed to enhance the dissolution of GB by formulating the drug as a proniosomes which then improves the pharmacological effect. GB proniosomal formulations were prepared using a slurry method with sucrose as a carrier. The formulations were characterized by particle size, zeta potential, entrapment efficiency %, flow properties of the powder, and in vitro dissolution study. The pharmacological effect was also assessed by determining and measuring the fasting blood glucose level (BGL) before and after the treatment. Formulating GB proniosomes with the slurry method produces a free-flowing powder with a particle size range from 190.050 ± 43.204 to 1369.333 ± 150.407 nm and the zeta potential was above 20 mV (-24 to -58 mV), indicating good stability. The dissolution rate for all formulations was higher than that of the pure drug, indicating the efficiency of the proniosome in enhancing the drug solubility. A significant reduction in the fasting blood glucose level (73 %) was observed in animals treated with proniosomal formulation with no sign of liver damage. In contrast, the pharmacodynamics results show a significant reduction in fasting blood glucose level for animals treated with proniosomes compared to a 17.6 % reduction in BGL after treatment with pure drug. Moreover, the histopathological results showed no sign of liver damage that occurred with proniosomal treatment. GB proniosomal formulations is a promising drug delivery system with good therapeutic efficacy and stability.

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.

Proniosome: A Promising Approach for Vesicular Drug Delivery

Different types of drug delivery systems are intended to deliver therapeutic agents to the appropriate site of interest to get desired pharmacological effect. In the field of drug delivery, the advancement of nanotechnology helps develop novel dosage forms such as liposome, noisome, and proniosome. Proniosomes are promising drug carriers, that are dry formulations, and after hydration, are converted to noisome dispersion. Dry proniosomal powder can deliver a unit dose of the drug with improved drug stability and solubility. By using this formulation, both the hydrophilic and lipophilic drugs can be delivered through different routes like oral, topical, transdermal, vaginal, etc. This review revolves on different features of proniosomes such as their structure, formulation materials of proniosomes, preparation methods, evaluation, and application.

Development of a Novel Bilosomal System for Improved Oral Bioavailability of Sertraline Hydrochloride: Formulation Design, In Vitro Characterization, and Ex Vivo and In Vivo Studies

This study was proposed to develop an optimized sertraline hydrochloride (SER)-loaded bilosomal system and evaluate its potential for enhancement of drug oral bioavailability. A full 2³ factorial design was used to prepare SER-loaded bilosomal dispersions by thin film hydration using span 60, cholesterol (CHL), and sodium deoxycholate (SDC). The investigated factors included the total concentration of span 60 and CHL (X₁), span 60:CHL molar ratio (X₂), and SER:SDC molar ratio (X₃). The studied responses were entrapment efficiency (EE%) (Y₁), zeta potential (Y₂), particle size (Y₃), and in vitro % drug released at 2 (Y₄), 8 (Y₅), and 24 h (Y₆). The selected optimal bilosomal dispersion (N1) composition was 0.5% w/v (X₁), 1:1 (X₂), and 1:2 (X₃). Then, N1 was freeze dried into FDN1 that compared with pure SER for in vitro drug release, ex vivo permeation through rabbit intestine, and in vivo absorption in rats. Moreover, storage effect on FDN1 over 3 months was assessed. The optimal dispersion (N1) showed 68 ± 0.7% entrapment efficiency, - 41 ± 0.78 mV zeta potential, and 377 ± 19 nm particle size. The freeze-dried form (FDN1) showed less % drug released in simulated gastric fluids with remarkable sustained SER release up to 24 h compared to pure SER. Moreover, FDN1 showed good stability, fivefold enhancement in SER permeation through rabbit intestine, and 222% bioavailability enhancement in rats' in vivo absorption study compared to pure SER. The SER-loaded bilosomal system (FDN1) could improve SER oral bioavailability with minimization of gastrointestinal side effects.

The Optimized Delivery of Triterpenes by Liposomal Nanoformulations: Overcoming the Challenges

The last decade has witnessed a sustained increase in the research development of modern-day chemo-therapeutics, especially for those used for high mortality rate pathologies. However, the therapeutic landscape is continuously changing as a result of the currently existing toxic side effects induced by a substantial range of drug classes. One growing research direction driven to mitigate such inconveniences has converged towards the study of natural molecules for their promising therapeutic potential. Triterpenes are one such class of compounds, intensively investigated for their therapeutic versatility. Although the pharmacological effects reported for several representatives of this class has come as a well-deserved encouragement, the pharmacokinetic profile of these molecules has turned out to be an unwelcomed disappointment. Nevertheless, the light at the end of the tunnel arrived with the development of nanotechnology, more specifically, the use of liposomes as drug delivery systems. Liposomes are easily synthesizable phospholipid-based vesicles, with highly tunable surfaces, that have the ability to transport both hydrophilic and lipophilic structures ensuring superior drug bioavailability at the action site as well as an increased selectivity. This study aims to report the results related to the development of different types of liposomes, used as targeted vectors for the delivery of various triterpenes of high pharmacological interest.

New Peceol™/Span™ 60 Niosomes Coated with Chitosan for Candesartan Cilexetil: Perspective Increase in Absolute Bioavailability in Rats

PURPOSE

Candesartan cilexetil (CC), a prodrug of candesartan (CDT), is a class II BCS drug that suffers from poor oral bioavailability because of low aqueous solubility, P-gp efflux and first-pass metabolism. The absolute bioavailability reported for CC was only 15% and the methods to increase it remain elusive, thus the aim of our work was to prepare new CC-loaded niosomes encompassing, for the first time, glycerol monooleate GMO (Peceol™), as P-gp efflux inhibitor and promoter of lymphatic transport with Span™ 60 as bioenhancer. The prepared niosomes were further coated with chitosan for augmenting the CC oral absorption.

METHODS

The niosomes were prepared by thin film hydration method through quality by design approach, using two levels of each of three critical process parameters (CPPs), namely, XA (the molar ratio of surfactant mixture to cholesterol) at a ratio of 1:1 or 2:1; XB (the molar ratio of Span™ 60 to Peceol™) at a ratio of 1:1 or 2:1; and XC (the drug amount) at 15 mg or 30 mg. The investigated critical quality attributes (CQAs) were entrapment efficiency percent, particle size, and polydispersity index. The optimized uncoated and chitosan coated formulations were subjected to DSC and stability study. In vitro drug release, biocompatibility with Caco-2 cells and lastly the absolute bioavailability evaluation in rats were assessed.

RESULTS

The physical properties of the optimized and stable niosomes were satisfactory. The ingredients were compatible with each other and biocompatible with Caco-2 cells. The synergistic combination of Peceol™ and Span™ 60 probably surmounted the P-gp efflux with an increase in oral absolute bioavailability of niosomes to five times that of CC suspension.

CONCLUSION

The new niosomal formulations of CC containing Peceol™ with Span™ 60 and cholesterol either uncoated or coated with chitosan were a successful paradigm in achieving high oral absolute bioavailability and increased Caco-2 cells biocompatibility.

Design and optimization of nano invasomal gel of Glibenclamide and Atenolol combination: in vitro and in vivo evaluation

Background

There are many circumstances where chronic disease is associated with other disorders, especially in diseases such as diabetes with noncommunicable disease risk factors, such as hypertension. The current therapies for treating such chronic comorbid diseases are limited and challenging due to the difficulties in overcoming the side effects from complex therapeutic treatment regimen. The present study is aimed to develop and optimize the combinational nano invasomal gel of Glibenclamide (GLB) and Atenolol (ATN) as a novel combination therapy for comorbid treatment of diabetic hypertensive patients. The developed formulations were characterized for various parameters, including in-vitro skin permeation, skin irritation, in-vivo antidiabetic, and antihypertensive activities.

Results

OCNIG showed that the % entrapment efficiency of GLB is 96.67 ± 0.65% and % entrapment efficiency of ATN is 93.76 ± 0.89%, flux of GLB (240.43 ± 1.76 μg/cm2/h), and flux of ATN (475.2 ± 1.54 μg/cm2/h) which was found to conform to the expected value. The results indicated desired release and permeation profiles. Optimized formulation showed significant pharmacokinetic properties, which shows improvement in bioavailability by 134.30% and 180.32% respectively for two drugs, when compared to marketed oral preparation. Pharmacodynamic studies showed improved and prolonged management of diabetes and hypertension in Wistar rats, compared to oral and drug-loaded nano invasomes formulations.

Conclusion

Overall, the results showed that nano invasomal gel was found to be a useful and promising transdermal delivery system for the treatment of concurrent diseases.

DAP derived fatty acid amide organogelators as novel carrier for drug incorporation and pH-responsive release

Low-molecular mass fatty acid amide gelators were synthesized using 2,6-diaminopyridine as a linker and alkyl chains of varying lengths. The prepared organogel-elusions are able to trap and release ibuprofen molecule without changing its structure and activity.

Design, Characterization, and Application of a pH-Triggered In Situ Gel for Ocular Delivery of Vinpocetine

We developed a pH-triggered in situ gel (ISG) for ocular delivery of vinpocetine to achieve systemic absorption and a brain-targeting effect in rats. Carbopol acted as a gelling agent combined with hydroxypropyl methylcellulose (HPMC) as a viscosity-enhancing agent. The concentration of Carbopol (0.2%, w/v) and HPMC (1.5%, w/v) was optimized for the ISG system. The optimized formulation was evaluated for studies on release in vitro, rheology, differential scanning calorimetry, ocular irritation, residence time, and in vivo pharmacokinetics. The vinpocetine ISG stayed longer in rabbit eyes than vinpocetine ointment. In vivo pharmacokinetics showed that compared with vinpocetine ointment, vinpocetine ISG attained a peak plasma concentration and area under the curve that was 1-2 folds greater in rat plasma. The Drug Targeting Index (DTI) was 1.06 and 1.26 for vinpocetine ointment and vinpocetine ISG, respectively, after ocular administration, showing that vinpocetine ISG had better distribution in rat brain. These results revealed that a pH-triggered ISG system via ocular administration could be an alternative approach compared with traditional ophthalmic formulations.

Direct silica coating of drug crystals for ultra-high loading

To push the limit of synthetic control, we create a thin layer (5 nm) of silica on the surface of drug nanocrystals, achieving a loading content (88%) that approaches the theoretical limit. The uniform silica shell provides a tailored diffusion barrier for controlled drug release. The method can be generally applied to 11 organic crystals, including 4 drugs.

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.

Nanocarriers and Their Loading Strategies

Nanocarriers are of paramount significance for drug delivery and nanomedicine technology. Given the imperfect systems and nonideal therapeutic effects, there are works to be done in synthesis as much as in biological studies, if not more so. Building the foundation of synthesis would offer more tools and deeper insights for exploring the biological systems with extreme complexity. This review aims at a broad-scope summary and classification of nanocarriers for drug delivery, with focus on the synthetic strategy and structural implications. The nanocarriers are divided into four categories according to the loading principle: molecular-level loading, surface loading, matrix loading, and cavity loading systems. Making comparisons across diverse nanocarrier systems would make it easier to see the fundamental characteristics, from where the weakness can be addressed and the strengths combined. The systematic comparisons may also inspire new ideas and methods.

Release of small bioactive molecules from physical gels

Pharmaceutical drugs with low water solubility have always received great attention within the scientific community. The reduced bioavailability and the need of frequent administrations have motivated the investigation of new drug delivery systems. Within this context, drug carriers that release their payload in a sustained way and hence reduce the administration rate are highly demanded. One interesting strategy to meet these requirements is the entrapment of the drugs into gels. So far, the most investigated materials for such drug-loaded gels are derived from polymers and based on covalent linkages. However, over the last decade the use of physical (or supramolecular) gels derived from low molecular weight compounds has experienced strong growth in this field, mainly due to important properties such as injectability, stimuli responsiveness and ease of synthesis. This review summarizes the use of supramolecular gels for the encapsulation and controlled release of small therapeutic molecules.

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.

Pharmacodynamics of long-acting folic acid-receptor targeted ritonavir-boosted atazanavir nanoformulations

Long-acting nanoformulated antiretroviral therapy (nanoART) that targets monocyte-macrophages could improve the drug's half-life and protein-binding capacities while facilitating cell and tissue depots. To this end, ART nanoparticles that target the folic acid (FA) receptor and permit cell-based drug depots were examined using pharmacokinetic and pharmacodynamic (PD) tests. FA receptor-targeted poloxamer 407 nanocrystals, containing ritonavir-boosted atazanavir (ATV/r), significantly increased drug bioavailability and PD by five and 100 times, respectively. Drug particles administered to human peripheral blood lymphocyte reconstituted NOD.Cg-Prkdc(scid)Il2rg(tm1Wjl)/SzJ mice and infected with HIV-1ADA led to ATV/r drug concentrations that paralleled FA receptor beta staining in both the macrophage-rich parafollicular areas of spleen and lymph nodes. Drug levels were higher in these tissues than what could be achieved by either native drug or untargeted nanoART particles. The data also mirrored potent reductions in viral loads, tissue viral RNA and numbers of HIV-1p24+ cells in infected and treated animals. We conclude that FA-P407 coating of ART nanoparticles readily facilitates drug carriage and antiretroviral responses.