Transdermal drug delivery of paroxetine through lipid-vesicular formulation to augment its bioavailability

Development and pharmacological evaluation of liposomes and nanocapsules containing paroxetine hydrochloride

Depression is one of the most common psychiatric disorders. Nanotechnology has emerged to optimize the pharmacological response. Therefore, the aim of this work was to develop and characterize liposomes and nanocapsules containing paroxetine hydrochloride and evaluate their antidepressant-like effect using the open field and tail suspension tests in mice. Liposomes and nanocapsules were prepared using the reverse-phase evaporation and nanoprecipitation methods, respectively. The particle size of the formulation ranged from 121.81 to 310.73 nm, the polydispersity index from 0.096 to 0.303, the zeta potential from -11.94 to -34.50 mV, the pH from 5.31 to 7.38, the drug content from 80.82 to 94.36 %, and the association efficiency was 98 %. Paroxetine hydrochloride showed slower release when associated with liposomes (43.82 %) compared to nanocapsules (95.59 %) after 10 h. In Vero cells, in vitro toxicity showed a concentration-dependent effect for paroxetine hydrochloride nanostructures. Both nanostructures decreased the immobility time in the TST at 2.5 mg/kg without affecting the number of crossings in the open field test, suggesting the antidepressant-like effect of paroxetine. In addition, the nanocapsules decreased the number of groomings, reinforcing the anxiolytic effect of this drug. These results suggest that the nanostructures were effective in preserving the antidepressant-like effect of paroxetine hydrochloride even at low doses.

Long-acting transdermal drug delivery formulations: Current developments and innovative pharmaceutical approaches

Transdermal administration remains an active research and development area as an alternative route for long-acting drug delivery. It avoids major drawbacks of conventional oral (gastrointestinal side effects, low drug bioavailability, and need for multiple dosing) or parenteral routes (invasiveness, pain, and psychological stress and bio-hazardous waste generated from needles), thereby increasing patient appeal and compliance. This review focuses on the current state of long-acting transdermal drug delivery, including adhesive patches, microneedles, and molecularly imprinted polymeric systems. Each subsection describes an approach including key considerations in formulation development, design, and process parameters with schematics. An overview of commercially available conventional (adhesive) patches for long-acting drug delivery (longer than 24 h), the reservoir- and matrix-type systems under preclinical evaluation, as well as the advanced transdermal formulations, such as the core-shell, nanoformulations-incorporated and stimuli-responsive microneedles, and 3D-printed and molecularly imprinted polymers that are in development, is also provided. Finally, we elaborated on translational aspects, challenges in patch formulation development, and future directions for the clinical advancement of new long-acting transdermal products.

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.

Fabrication of solid lipid nanoparticles-based patches of paroxetine and their ex-vivo permeation behaviour

Paroxetine is not suitable for oral administration due to its extensive first-pass metabolism, thus resulting in less bioavailability. This study aimed to prepare novel paroxetine-loaded solid lipid nanoparticles (SLNs) based sustained-release transdermal patches to overcome these problems by enhancing drug absorption and bioavailability. Nine formulations of paroxetine SLNs were prepared by the hot melt-homogenization method using different concentrations of glycerol monostearate (Kolliwax) and Tween 80. Then these prepared SLNs were incorporated in a matrix type transdermal patch having a matrix of ethyl cellulose and polyvinyl pyrrolidone in 3:2 with polyvinyl alcohol. The SLNs showed a particle size range of 113-230 nm and an entrapment efficiency of 85.14%. The SLNs showed sustained paroxetine release (77.86-95.63% release) up to 48 h. FTIR studies showed no interaction between drug and formulation components. Paroxetine is evenly distributed in an amorphous form in SLNs, as demonstrated by DSC as well as PXRD analysis. SLNs formulated patches showed higher drug permeation through the skin than drug-based transdermal patches., Draize patch test revealed no sign of erythema after applying paroxetine-loaded SLN patches (score 0) as observed with the marketed product. The developed SLNs based transdermal patches showed increased permeability and sustained release behaviour.

Antibacterial activity of paroxetine against Staphylococcus aureus and possible mechanisms of action

Aim: To evaluate the antibacterial activity of paroxetine alone and associated with oxacillin against isolates of methicillin-sensitive and -resistant Staphylococcus aureus. Materials & methods: The broth microdilution and checkerboard techniques were used, with investigation of possible mechanisms of action through flow cytometry, fluorescence microscopy and molecular docking, in addition to scanning electron microscopy for morphological analysis. Results: Paroxetine showed a MIC of 64 μg/ml and bactericidal activity, mostly additive interactions in combination with oxacillin, evidence of action on genetic material and membrane, morphological changes in microbial cells and influence on virulence factors. Conclusion: Paroxetine has antibacterial potential from the perspective of drug repositioning.

Recent Options and Techniques to Assess Improved Bioavailability: In Vitro and Ex Vivo Methods

Bioavailability assessment in the development phase of a drug product is vital to reveal the disadvantageous properties of the substance and the possible technological interventions. However, in vivo pharmacokinetic studies provide strong evidence for drug approval applications. Human and animal studies must be designed on the basis of preliminary biorelevant experiments in vitro and ex vivo. In this article, the authors have reviewed the recent methods and techniques from the last decade that are in use for assessing the bioavailability of drug molecules and the effects of technological modifications and drug delivery systems. Four main administration routes were selected: oral, transdermal, ocular, and nasal or inhalation. Three levels of methodologies were screened for each category: in vitro techniques with artificial membranes; cell culture, including monocultures and co-cultures; and finally, experiments where tissue or organ samples were used. Reproducibility, predictability, and level of acceptance by the regulatory organizations are summarized for the readers.

Development and Optimization of Hyaluronic Acid-Poloxamer In-Situ Gel Loaded with Voriconazole Cubosomes for Enhancement of Activity against Ocular Fungal Infection

Fungal eye infections are largely disseminated, especially in developing countries where they may leave over half a million people blind per year. The current study aims to boost the voriconazole antifungal efficiency via loading it as cubosomes (VZ-Cub) into hyaluronic acid and poloxamer-based ocular in situ gel. VZ-Cub were fabricated applying Box-Behnken design and employing phytantriol, poloxamer F127, and VZ amounts as independent variables. The produced nano vesicles were evaluated for the dependent variables of particle size (PS), entrapment efficiency (EE%), and transcorneal steady-state flux (Jss) of the VZ, and, the obtained optimal VZ-Cub was loaded into an in situ gel base to enhance its ocular residence time. The in situ gel formulation was tested for its gelation temperature, drug release behavior, transcorneal permeation effects, and antifungal activity. The optimized VZ-Cub consisted of 100 mg of phytantriol, 60 mg of poloxamer F127, and 21 mg of VZ. This formulation led to a minimum PS of 71 nm, an EE% of 66%, Jss value of 6.5 µg/(cm²·min), and stability index of 94 ± 2%. The optimized VZ-Cub-loaded in situ gel released 84% VZ after 12 h and yielded a 4.5-fold increase in drug permeation compared with the VZ aqueous dispersion. The antifungal activity, which was obtained by measuring the fungal growth inhibition zones, revealed that the VZ-Cub-loaded in situ gel formulation had a 3.89-fold increase in antifungal activity compared with the VZ dispersion. In summary, an ocular in situ gel loaded with VZ-Cub could be an effective novel nano-paradigm with enhanced transcorneal permeation and antifungal properties.

Preparation and optimization of aloe ferox gel loaded with Finasteride-Oregano oil nanocubosomes for treatment of alopecia

Alopecia areata is a skin disorder characterized by scarless, localized hair loss that is usually managed by topical treatments that might further worsen the condition. Therefore, the current study aimed to develop nano-cubosomes loaded with finasteride (FI) and oregano oil (Or) to improve drug solubility and permeation through skin and then incorporate it into an aloe ferox gel base. An l-optimal coordinate exchange design was adopted to optimize nano-cubosomes. Phytantriol and Alkyl Acrylate were employed as the lipid material, and surfactant respectively for cubosomes manufacture. The produced formulations were assessed for their particle size, entrapment efficiency (EE%), FI steady-state flux (Jss) and minimum inhibitory concentration (MIC) against Pro-pionibacterium acnes. Optimal FI-Or-NCu had a particle size of 135 nm, EE% equals 70%, Jss of 1.85 μg/cm2.h, and MIC of 0.44 μg/ml. The optimum formulation loaded gel gained the highest drug release percent and ex vivo skin permeation compared to FI aqueous suspension, and pure FI loaded gel. Aloe ferox and oregano oil in the optimized gel formulation had a synergistic activity on the FI permeation across the skin and against the growth of p. acne bacteria which could favor their use in treating alopecia. Thus, this investigation affirms the ability of FI-Or-NCu loaded aloe ferox gel could be an effective strategy that would enhance FI release and permeation through skin and maximize its favorable effects in treating alopecia.

Formulation and Development of Oral Fast-Dissolving Films Loaded with Nanosuspension to Augment Paroxetine Bioavailability: In Vitro Characterization, Ex Vivo Permeation, and Pharmacokinetic Evaluation in Healthy Human Volunteers

Paroxetine (PX) is the most potent serotonin reuptake inhibitor utilized in depression and anxiety treatment. It has drawbacks, such as having a very bitter taste, low water solubility, and undergoing extensive first pass metabolism, leading to poor oral bioavailability (<50%). This work aimed to develop and optimize palatable oral fast-dissolving films (OFDFs) loaded with a paroxetine nanosuspension. A PX nanosuspension was prepared to increase the PX solubility and permeability via the buccal mucosa. The OFDFs could increase PX bioavailability due to their rapid dissolution in saliva, without needing water, and the rapid absorption of the loaded drug through the buccal mucosa, thus decreasing the PX metabolism in the liver. OFDFs also offer better convenience to patients with mental illness, as well as pediatric, elderly, and developmentally disabled patients. The PX nanosuspension was characterized by particle size, poly dispersity index, and zeta potential. Twelve OFDFs were formulated using a solvent casting technique. A 2² × 3¹ full factorial design was applied to choose the optimized OFDF, utilizing Design-Expert^® software (Stat-Ease Inc., Minneapolis, MN, USA). The optimized OFDF (F1) had a 3.89 ± 0.19 Mpa tensile strength, 53.08 ± 1.28% elongation%, 8.12 ± 0.13 MPa Young's modulus, 17.09 ± 1.30 s disintegration time, and 96.02 ± 3.46% PX dissolved after 10 min. This optimized OFDF was subjected to in vitro dissolution, ex vivo permeation, stability, and palatability studies. The permeation study, using chicken buccal pouch, revealed increased drug permeation from the optimized OFDF; with a more than three-fold increase in permeation over the pure drug. The relative bioavailability of the optimized OFDF in comparison with the market tablet was estimated clinically in healthy human volunteers and was found to be 178.43%. These findings confirmed the success of the OFDFs loaded with PX nanosuspension for increasing PX bioavailability.

Nanocubosomal based in situ gel loaded with natamycin for ocular fungal diseases: development, optimization, in-vitro, and in-vivo assessment

Natamycin (NT) is a synthetic broad-spectrum antifungal used in eye drops. However, it has low solubility and high molecular weight, limiting its permeation, and generally causes eye discomfort or irritation when administered. Therefore, the present study aimed to develop an ophthalmic in situ gel formulation with NT-loaded cubosomes to enhance ocular permeation, improve antifungal activity, and prolong the retention time within the eye. The NT-loaded cubosome (NT-Cub) formula was first optimized using an I-optimal design utilizing phytantriol, PolyMulse, and NT as the independent formulation factors and particle size, entrapment efficiency %, and inhibition zone as responses. Phytantriol was found to increase particle size and entrapment efficiency %. Higher levels of PolyMulse slightly increased the inhibition zone whereas a decrease in particle size and EE% was observed. Increasing the NT level initially increased the entrapment efficiency % and inhibition zone. The optimized NT-Cub formulation was converted into an in situ gel system using 1.5% Carbopol 934. The optimum formula showed a pH-sensitive increase in viscosity, favoring prolonged retention in the eye. The in vitro release of NT was found to be 71 ± 4% in simulated tear fluid. The optimum formulation enhanced the ex vivo permeation of NT by 3.3 times compared to a commercial formulation and 5.2 times compared to the NT suspension. The in vivo ocular irritation test proved that the optimum formulation is less irritating than a commercial formulation of NT. This further implies that the developed formulation produces less ocular irritation and can reduce the required frequency of administration.

Fluvastatin-Loaded Emulsomes Exhibit Improved Cytotoxic and Apoptosis in Prostate Cancer Cells

Fluvastatin (FLV) is known to inhibit the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA), which is over-expressed in various cancers. FLV has been reported to decrease cancer development and metastasis. However, because of low bioavailability, extensive first-pass metabolism and short half-life of FLV (1.2 h), it is not appropriate for clinical application. Therefore, FLV-loaded emulsomes were formulated and optimized using Box-Behnken experimental design to achieve higher efficiency of formulation. Antitumor activity of optimized FLV-loaded emulsomes was evaluated in prostate cancer cells using cell cytotoxicity, apoptotic activity, cell cycle analysis, and enzyme-linked immunosorbent assay. The FLV-loaded emulsomes exhibited a monodispersed size distribution with a mean particle size less than 100 nm as measured by zetasizer. The entrapment efficiency was found to be 93.74% with controlled drug release profile. FLV-EMLs showed a significant inhibitory effect on the viability of PC3 cells when compared to the free FLV (P < 0.0025). Furthermore, FLV-EMLs showed significant arrest in G2/M and increase in percentage of apoptotic cells as compared to free FLV. FLV-EMLs were more effective than free FLV in reducing mitochondrial membrane potential and increase in caspase-3 activity. These results suggesting that FLV-EMLs caused cell cycle arrest which clarifies its significant antiproliferative effect compared to the free drug. Therefore, optimized FLV-EMLs may be an effective carrier for FLV in prostate cancer treatment.

Transdermal Route: A Viable Option for Systemic Delivery of Antidepressants

The high rise in the population suffering from depression depicts the need for improved and highly effective treatment options for this condition. Efforts to develop existing drugs into user-friendly dosage forms with a number of advantages in major depressive states, including but not limited to: sustained drug release, reduced drug dosing frequency, improved tolerance and adherence, suitability for use in diverse populations and different treatment scenarios, as well as less central nervous system side effects are required. One such non-invasive drug delivery route that could provide the aforementioned benefits in the treatment of depression is the transdermal route. A number of conventional and emerging transdermal delivery strategies have been investigated for some potent antidepressants and results depict the potential of this route as a viable means for systemic delivery of therapeutically relevant doses of the tested agents, with Emsam®, the commercially available patch of selegiline, being an evidence for the same. The investigated approaches include the formulation of transdermal patches, use of vesicular drug carriers, pro-drug approach, microemulsification, chemical as well as physical enhancement technologies. This review provides a comprehensive account of the rationale, developments made till date, scope and future prospects of delivering antidepressants via the transdermal1 route of administration.

Curcumin-loaded proniosomal gel as a biofreindly alternative for treatment of ocular inflammation: In-vitro and in-vivo assessment

Ocular inflammation is a natural defensive phenomenon, but, it results in discomfort in the eye; as well as makes the eye vulnerable to other diseases. The aim of this work is to investigate that Curcumin (CUR) could be an effective safer biofreindly alternative for treatment of ocular inflammation. Complete in-vitro characterization of proniosomal gel loading-CUR using different surfactants was studied. A comparative in-vivo evaluation of selected formulation to a marketed corticosteroid drops in induced-eye inflammation model in rabbits was assessed. The selected formulation (F_{Cr 300}) composed of Cremophore RH surfactant, lecithin and cholesterol (9:9:1) loading CUR (1.2% w/w). The formulation showed mean PS(212.0 ± 0.1)nm, PDI (0.3 ± 0.1) , ZP(-5.1 ± 0.2)mV and % EE (96.0 ± 0.1). TEM showed multilamellar circular shaped niosomes with smooth surface. SEM showed ruptured vesicles for the lyophilized formula. Selected proniosomal gel showed enhanced permeability 3.22-fold and 1.76-fold higher than CUR dispersion and its lyophilized form respectively. Both proniosomal gel (F_Cr300) and corticosteroid drops reduced the induced inflammatory signs effectively by 40% on day-one and complete recovery on day-four. This anti-inflammatory result was confirmed by histopathological analysis after treatment. Assessment of cumulative IOP as a predicted side effect verified the goal of this work. In conclusion, the use of CUR as a natural biofreindly alternative to the current chemical conventional ocular anti-inflammatory treatment protocols is comparable as an anti-inflammatory drug with much less side effects.

Niosomes: Do They Increase the Potency of Topical Natamycin Ketorolac Formula in Treating Aspergillus Keratitis? An Experimental Study

Purpose: Formulation of new drug delivery system as Natamycin (NT)-loaded nanoparticle niosomal formulae mixed in different polymer gel, with the addition of ketorolac tromethamine (KETR). Pharmaceutical and experimental assessments to evaluate their safety and efficacy in treating Aspergillus keratitis. Methods: NT nanoparticle niosomes prepared by reverse-phase evaporation technique were mixed in different polymers, with the addition of KETR. Two formulae are evaluated in this study: F1 [NT-loaded nanoparticle niosomes/0.5% KETR 4% carboxymethyl cellulose (Na.CMC) gel], F2 [NT-loaded nanoparticle niosomes/0.5% KETR 2% hydroxypropylmethyl cellulose (HPMC)-E4 gel], and mixed marketed products (MMP), namely Natamet^® and Ketoroline^® suspension eye drops. NT-loaded nanoparticle niosomes/0.5% KETR were evaluated through viscosity determination, mucoadhesive attractive force, and in vitro NT release studies. The in vivo antifungal evaluation was performed on 45 albino rabbits, Aspergillus species were inoculated in right corneas of all rabbits, and then rabbits were subdivided into 3 groups, 15 rabbits each: Group A: received F1, Group B: received F2, and Group C: received MMP. Daily examination of rabbits was performed for evaluation of corneal infiltration, and signs of iritis. Two weeks later, rabbits were euthanized; their corneas were dissected at the limbus and sent for histopathological evaluation. Results: F1 had a higher viscosity and more mucoadhesive power than F2, and showed better results on corneal infiltration, and level of hypopyon. These results were consistent with the histopathological examination. Conclusion: The formula of NT-loaded nanoparticle niosomes/0.5% KT 4% Na.CMC gel has the best results from all pharmaceutical in vitro evaluations and a better cure percent in experimental application.

Potential application of liposomal nanodevices for non-cancer diseases: an update on design, characterization and biopharmaceutical evaluation

Liposomes, lipid-based vesicular systems, have attracted major interest as a means to improve drug delivery to various organs and tissues in the human body. Recent literature highlights the benefits of liposomes for use as drug delivery systems, including encapsulating of both hydrophobic and hydrophilic cargos, passive and active targeting, enhanced drug bioavailability and therapeutic effects, reduced systemic side effects, improved cargo penetration into the target tissue and triggered contents release. Pioneering work of liposomes researchers led to introduction of long-circulating, ligand-targeted and triggered release liposomes, as well as, liposomes containing nucleic acids and vesicles containing combination of cargos. Altogether, these findings have led to widespread application of liposomes in a plethora of areas from cancer to conditions such as cardiovascular, neurologic, respiratory, skin, autoimmune and eye disorders. There are numerous review articles on the application of liposomes in treatment of cancer, which seems the primary focus, whereas other diseases also benefit from liposome-mediated treatments. Therefore, this article provides an illustrated detailed overview of liposomal formulations, in vitro characterization and their applications in different disorders other than cancer. Challenges and future directions, which must be considered to obtain the most benefit from applications of liposomes in these disorders, are discussed.

Fabrication of Anti-HSV-1 Curcumin Stabilized Nanostructured Proniosomal Gel: Molecular Docking Studies on Thymidine Kinase Proteins

Curcumin is a dietary compound with accrued evidence of antiviral activity. Poor solubility and permeation renders curcumin a good applicant for incorporation into proniosomes. The intent of this study was to formulate curcumin proniosomal gel for topical application and the evaluation of its in-vitro, ex-vivo activities against Herpes Simplex virus type 1 (HSV-1), as well as molecular docking studies on HSV-1 thymidine kinase proteins. Coacervation phase separation tactic, using 23 full factorial design, was used in the preparation of different proniosomes. Cytotoxicity of the selected formulae (F4 and F8) was evaluated on the Vero cell line. Optimal formulae (F4 and F8) showed entrapment efficiency of 97.15 ± 2.47% and 95.85 ± 2.9%, vesicle size of 173.7 ± 2.26 nm and 206.15 ± 4.17 nm and percentages curcumin released after 3 h of 51.9 ± 1.4% and 50.5 ± 1.1%, respectively. Ex-vivo permeation studies demonstrated that the optimal formulae markedly improved the dermal curcumin delivery. Curcumin proniosomal gel formulae exhibited 85.4% reduction of HSV-1 replication. The ability of curcumin to interact with the key amino acids in the enzyme binding sites of 1KI7, 1KI4, and 1E2P, as indicated by its docking pattern, rationalized its observed activity. Therefore, curcumin proniosomes could be considered as a successful topical delivery system for the treatment of HSV-1.

Advancement of Lipid-Based Nanocarriers and Combination Application with Physical Penetration Technique

On account of the advantages of transdermal delivery and the application situation of transcutaneous technology in transdermal delivery, the article critically comments on nanosystems as permeation enhancement model. Nanosystems possess great potential for transcutaneous drug delivery. This review focuses on recent advances in lipid-based nanocarriers, including liposome, transfersomes, ethosomes, nanoemulsions, solid lipid nanoparticles, nanostructured lipid carriers and combination application of the lipid-based nanocarriers with microneedle, iontophoresis, electroporation and sonophoresis in the field for the development of the transdermal drug delivery system. We attempted to give an overview of lipid-based nanocarriers with the aim to improve transdermal and dermal drug delivery. A special focus is given to the nanocarrier composition, characteristic and interaction mechanisms through the skin. Recent combination applications of lipid-based nanocarriers with the physical penetration technology demonstrate the superiority of the combined use of nanocarriers and physical methods in drug penetration enhancement compared to their single use. In the future, lipidbased nanocarriers will play a greater role in the field of transdermal and dermal drug delivery.

Metformin hydrochloride and wound healing: from nanoformulation to pharmacological evaluation

Niosomes as drug delivery systems have the ability to decrease drugs' side effects and increase their therapeutic effectiveness. Metformin HCl is an oral antihyperglycemic agent belonging to biguanides. It is the most commonly chosen drug as a startup therapy for patients newly diagnosed with type 2 diabetes. This study aims to encapsulate metformin HCl inside niosomes to be used as a transdermal formulation helping to prolong its antidiabetic effect and investigate its ability to enhance wound healing in diabetic patients. Thin film hydration method was used to prepare metformin HCl niosomes using different proportions of Span 60, Span 40, Tween 80, and cholesterol. All formulations were characterized using transmission electron microscope, zeta potential, and vesicle size. In vitro release studies, stability studies and in vivo evaluation were conducted on selected niosomal formulations. The results of entrapment efficiency ranged from 13% to 32%. Vesicle sizes were determined in nano-range. The in vitro release profile of metformin HCl from niosomes occurred in two consecutive phases. Biological evaluation on diabetic rats revealed that metformin HCl niosomal gel given every 2 days showed a better sustained antidiabetic effect than oral doses given daily. It also showed an improvement in wound healing for diabetic rats given metformin formulations compared to nontreated ones.

Gastroretentive raft liquid delivery system as a new approach to release extension for carrier-mediated drug

Gabapentin (GBP), an antiepileptic and anti-neuropathic agent, suffers from short half-life (5-7 h), has narrow absorption window, and is absorbed via carrier-mediated mechanism resulting in frequent dosing, poor compliance, and poor bioavailability (<60%). Moreover, GBP is a freely water-soluble drug, thus it is considered a challenging candidate to be formulated as extended release dosage form. In this study, raft forming systems were investigated as a potential drug delivery system for prolonging gastric residence time of GBP. A 23 full factorial design was adopted to study the effect of formulation variables (% gellan gum, % GMO, and % LM-pectin 101), on the percent of GBP released at different time intervals (1, 5, and 8 h) as well as the gel strength, and thus was achieved an optimized formula with zero-order release profile suitable for once-daily administration. In vivo assessment was performed in rats to evaluate gastric residence of the gel formed. In addition, the oral bioavailability of GBP relative to commercially available Neurontin® immediate release oral solution was also investigated. Significant increase was observed for Cmax, AUC(0-t), and AUC(0-∞). The increase in relative bioavailability of GBP from the optimized formula was 1.7 folds.

Finasteride nano-transferosomal gel formula for management of androgenetic alopecia: ex vivo investigational approach

Introduction

Finasteride (FIN) is known as type II 5α-reductase inhibitor, which has been approved for the treatment and prevention of androgenetic alopecia. Administration of FIN by oral route has led to undesirable systemic side effects that include mood disturbance, gynecomastia, decreased libido, erectile dysfunction, and ejaculation disorder. The aim was to improve FIN delivery through skin layers and hair follicles that could possibly reduce its major side effects resulting from long-term oral administration for the treatment and prevention of male pattern baldness.

Materials and methods

FIN was formulated as nano-transferosomal (NTF) gel formulations (F1–3). The prepared formulations were characterized for encapsulation efficiency, particle size, ex vivo skin permeation, and kinetic modeling. In addition, visualization of NTF skin penetration using a fluorescence laser microscope was carried out for the selected formula (F2).

Results and discussion

The results showed that FIN encapsulation efficiency percentage was 69.72 ± 8.36, 89.43 ± 6.82, and 93.1 ± 1.93 for F1, F2, and F3, respectively. FIN-NTF average vesicle sizes were 299.6 ± 45.6, 171 ± 25.6, and 197.4 ± 29.1 nm for F1, F2, and F3, respectively. FIN-NTF formulations (F1–3) showed enhancement and improvement in the amount of FIN permeated compared with raw FIN gel formula. The NTF formula revealed uniform fluorescence (rhodamine) intensity across rat skin, which indicated improved delivery through skin layers compared with control gel formula.

Conclusion

These results indicated that NTF gel formula showed the ability to boost FIN delivery across skin layers and could be applied as an alternative for oral therapy.

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.

InVitro, Ex Vivo, and In Vivo Evaluation of a Dual pH/Redox Responsive Nanoliposomal Sludge for Transdermal Drug Delivery

A dual pH/redox responsive copper-glyglycine-prednisolone succinate-loaded nanoliposomal (NL) sludge was successfully synthesized and optimized using a Box-Behnken design of experiments. Preformulation design variables indicated that relative ratios of phospholipids, considerably influences NL size, thus altering the degree of drug loading in the formulation. In vitro evaluation further confirmed optimum release kinetics of the NL sludge, corresponding closely to ex vivo permeation studies, demonstrating effective transdermal delivery of prednisone succinate (PS) through a pig skin model, which closely resembles human skin anatomy. The pH/redox stimuli responsiveness of the NL sludge further demonstrated superior properties in vivo using a Sprague-Dawley rat model. The NL sludge displayed the greatest release of PS within 24 h of evaluation, falling within the acceptable therapeutic range of PS dose efficiency. In vivo results further displayed the greatest absorption of PS under inflammatory induced conditions, thus confirming the unique pH/redox responsive properties of the NL sludge. It was thus confirmed that the copper-glyglycine-prednisolone succinate-loaded NL sludge has significant potential for application in chronic inflammatory conditions such as tumor necrosis factor receptor-associated periodic syndrome (TRAPS), designed to release an effective dose of corticosteroid, as a transdermal drug delivery formulation, for effective therapeutic efficacy.

Recent advances in nanocarrier-loaded gels: Which drug delivery technologies against which diseases?

The combination of pharmaceutical technologies can be a wise choice for developing innovative therapeutic strategies. The association of nanocarriers and gels provides new therapeutic possibilities due to the combined properties of the two technologies. Gels support the nanocarriers, localize their administration to the target tissue, and sustain their release. In addition to the properties afforded by the gel, nanocarriers can provide additional drug sustained release or different pharmacokinetic and biodistribution profiles than those from nanocarriers administered by the conventional route to improve the drug therapeutic index. This review focuses on recent (over the last ten years) in vivo data showing the advances and advantages of using nanocarrier-loaded gels. Liposomes, micelles, liquid and solid lipid nanocapsules, polymeric nanoparticles, dendrimers, and fullerenes are all nanotechnologies which have been recently assessed for medical applications, such as cancer therapy, the treatment of cutaneous and infectious diseases, anesthesia, the administration of antidepressants, and the treatment of unexpected diseases, such as alopecia.

Synthesis, preclinical, and pharmacokinetic evaluation of a new zoledronate derivative as a promising antiosteoporotic candidate using radiolabeling technique

A novel zoledronic acid (ZL) derivative, 3-(2-ethyl-4-methyi-1H-imidazole-1-yl)-1-hydroxy-1-phosphonopropyl phosphonic acid (EMIHPBP), was synthesized, characterized, and successfully radiolabeled with ^99m Tc. The in vivo biodistribution of ^99m Tc-EMIHPBP was investigated and compared with the previously reported zoledronate derivatives aiming to formulate a novel zoledronate derivative with a high-potential uptake to bone as a promising antiosteoporotic candidate. To further evaluate the bone uptake efficiency, the pharmacokinetics of ^99m Tc-EMIHPBP was investigated and showed that maximum concentration in bone (C_max ) was 31.60 ± 0.15%ID/gram after 60 minutes (t_max ). Cumulative residence of ^99m Tc-EMIHPBP in the bone [AUC _(0-∞) (%ID∙min/gram bone)] was 3685.23, mean residence time was 384.354 minutes, and the calculated bone bioavailability was 15.831%. Finally, the time needed for half of the ^99m Tc-EMIHPBP formulation to be eliminated from bone (t_1/2 ) was 263.914 minutes. Excellent bone uptake can be obtained 1-hour postinjection with high bone/blood ratio of 23.76 detected with gamma counter. The biodistribution and kinetic studies could recommend EMIHPBP as a promising antiosteoporotic candidate with high selectivity to the skeletal system and rapid clearance from soft tissues.

Superiority of liquid crystalline cubic nanocarriers as hormonal transdermal vehicle: comparative human skin permeation-supported evidence

OBJECTIVES

The aim of this investigation was to explore the feasibility of various nanocarriers to enhance progesterone penetration via the human abdominal skin.

METHODS

Four progesterone-loaded nanocarriers; cubosomes, nanoliposomes, nanoemulsions and nanomicelles were formulated and characterized regarding particle size, zeta potential, % drug encapsulation and in vitro release. Structural elucidation of each nanoplatform was performed using transmission electron microscopy. Ex vivo skin permeation, deposition ability and histopathological examination were evaluated using Franz diffusion cells.

RESULTS

Each nanocarrier was fabricated with a negative surface, nanometric size (≤ 270 nm), narrow size distribution and reasonable encapsulation efficiency. In vitro progesterone release showed a sustained release pattern for 24 h following a non-Fickian transport diffusion mechanism. All nanocarriers exhibited higher transdermal flux relative to free progesterone. Cubosomes revealed a higher skin penetration with transdermal steady flux of 48.57.10(-2) ± 0.7 µg/cm(2) h. Nanoliposomes offered a higher percentage of skin progesterone deposition compared to other nanocarriers. Based on the histopathological examination, cubosomes and nanoliposomes were found to be biocompatible for transdermal application. Confocal laser scanning microscopy confirmed the ability of fluoro-labeled cubosomes to penetrate through the whole skin layers.

CONCLUSION

The elaborated cubosomes proved to be a promising non-invasive nanocarrier for transdermal hormonal delivery.

Optimized nano-transfersomal films for enhanced sildenafil citrate transdermal delivery: ex vivo and in vivo evaluation

Sildenafil citrate (SLD) is a selective cyclic guanosine monophosphate-specific phosphodiesterase type 5 inhibitor used for the oral treatment of erectile dysfunction and, more recently, for other indications, including pulmonary hypertension. The challenges facing the oral administration of the drug include poor bioavailability and short duration of action that requires frequent administration. Thus, the objective of this work is to formulate optimized SLD nano-transfersomal transdermal films with enhanced and controlled permeation aiming at surmounting the previously mentioned challenges and hence improving the drug bioavailability. SLD nano-transfersomes were prepared using modified lipid hydration technique. Central composite design was applied for the optimization of SLD nano-transfersomes with minimized vesicular size. The independent variables studied were drug-to-phospholipid molar ratio, surfactant hydrophilic lipophilic balance, and hydration medium pH. The optimized SLD nano-transfersomes were developed and evaluated for vesicular size and morphology and then incorporated into hydroxypropyl methyl cellulose transdermal films. The optimized transfersomes were unilamellar and spherical in shape with vesicular size of 130 nm. The optimized SLD nano-transfersomal films exhibited enhanced ex vivo permeation parameters with controlled profile compared to SLD control films. Furthermore, enhanced bioavailability and extended absorption were demonstrated by SLD nano-transfersomal films as reflected by their significantly higher maximum plasma concentration (C max) and area under the curve and longer time to maxi mum plasma concentration (T max) compared to control films. These results highlighted the potentiality of optimized SLD nano-transfersomal films to enhance the transdermal permeation and the bioavailability of the drug with the possible consequence of reducing the dose and administration frequency.

Oral nanomedicine approaches for the treatment of psychiatric illnesses

Psychiatric illnesses are a leading cause of disability and morbidity globally. However, the preferred orally dosed pharmacological treatment options available for depression, anxiety and schizophrenia are often limited by factors such as low drug aqueous solubility, food effects, high hepatic first-pass metabolism effects and short half-lives. Furthermore, the discovery and development of more effective psychotropic agents has stalled in recent times, with the majority of new drugs reaching the market offering similar efficacy, but suffering from the same oral delivery concerns. As such, the application of nanomedicine formulation approaches to currently available drugs is a viable option for optimizing oral drug delivery and maximizing treatment efficacy. This review focuses on the various delivery challenges encountered by psychotropic drugs, and the ability of nanomedicine formulation strategies to overcome these. Specifically, we critically review proof of concept in vitro and in vivo studies of nanoemulsions/microemulsions, solid lipid nanoparticles, dendrimers, polymeric micelles, nanoparticles of biodegradable polymers and nanosuspensions, and provide new insight into the various mechanisms for improved drug performance. The advantages and limitations of current oral nanomedicine approaches for psychotropic drugs are discussed, which will provide guidance for future research directions and assist in fostering the translation of such delivery systems to the clinical setting. Accordingly, emphasis has been placed on correlating the in vitro/in vivo performance of these nanomedicine approaches with their potential clinical outcomes and benefits for patients.

Dendrimer-coupled sonophoresis-mediated transdermal drug-delivery system for diclofenac

The purpose of the present study was to develop a novel transdermal drug-delivery system comprising a polyamidoamine dendrimer coupled with sonophoresis to enhance the permeation of diclofenac (DF) through the skin. The novel transdermal drug-delivery system was developed by using a statistical Plackett–Burman design. Hairless male Wistar rat skin was used for the DF-permeation study. Coupling media concentration, ultrasound-application time, duty cycle, distance from probe to skin, and a third-generation polyamidoamine-dendrimer concentration were selected as independent variables, while in vitro drug release was selected as a dependent variable. Independent variables were found to be statistically significant (P<0.05). DF gel without dendrimer and ultrasound treatment to skin (passive delivery, run 13) showed 56.69 µg/cm² cumulative drug permeated through the skin, while the DF-dendrimer gel without sonophoresis treatment (run 14) showed 257.3 µg/cm² cumulative drug permeated through the skin after 24 hours. However, when the same gel was applied to sonophoresis-treated skin, drastic permeation enhancement was observed. In the case of run 3, the cumulative drug that permeated through the skin was 935.21 µg/cm². It was concluded that dendrimer-coupled sonophoresis-mediated transdermal drug delivery system has the potential to enhance the permeation of DF through the skin.

Effect of liposomal fluidity on skin permeation of sodium fluorescein entrapped in liposomes

The purpose of this study was to investigate the effect of ultradeformable liposome components, Tween 20 and terpenes, on vesicle fluidity. The fluidity was evaluated by electron spin resonance spectroscopy using 5-doxyl stearic acid and 16-doxyl stearic acid as spin labels for phospholipid bilayer fluidity at the C5 atom of the acyl chain near the polar head group (hydrophilic region) and the C16 atom of the acyl chain (lipophilic region), respectively. The electron spin resonance study revealed that Tween 20 increased the fluidity at the C5 atom of the acyl chain, whereas terpenes increased the fluidity at the C16 atom of the acyl chain of the phospholipid bilayer. The increase in liposomal fluidity resulted in the increased skin penetration of sodium fluorescein. Confocal laser scanning microscopy showed that ultradeformable liposomes with terpenes increase the skin penetration of sodium fluorescein by enhancing hair follicle penetration.

Liposomal hydrogel formulation for transdermal delivery of pirfenidone

CONTEXT

Pirfenidone (PFD) is an anti-fibrotic and anti-inflammatory agent indicated for the treatment of idiopathic pulmonary fibrosis (IPF). The current oral administration of PFD has several limitations including first pass metabolism and gastrointestinal irritation.

OBJECTIVE

The aim of this study is to investigate the feasibility of transdermal delivery of PFD using liposomal carrier system.

MATERIALS AND METHODS

PFD-loaded liposomes were prepared using soy phosphatidylcholine (SPC) and sodium cholate (SC). Encapsulation efficiency (EE) of PFD in liposomes was optimized using different preparation techniques including thin film hydration (TFH) method, direct injection method (DIM) and drug encapsulation using freeze-thaw cycles. In vitro drug release study was performed using dialysis membrane method. The skin permeation studies were performed using excised porcine ear skin model in a Franz diffusion cell apparatus.

RESULTS AND DISCUSSION

The average particle size and zeta-potential of liposomes were 191 ± 4.1 nm and -40.4 ± 4.5 mV, respectively. The liposomes prepared by TFH followed by 10 freeze-thaw cycles showed the greatest EE of 22.7 ± 0.63%. The optimized liposome formulation was incorporated in hydroxypropyl methyl cellulose (HPMC) hydrogel containing different permeation enhancers including oleic acid (OA), isopropyl myristate (IPM) and propylene glycol (PG). PFD-loaded liposomes incorporated in hydrogel containing OA and IPM showed the greatest flux of 10.9 ± 1.04 μg/cm(2)/h across skin, which was 5-fold greater compared with free PFD. The cumulative amount of PFD permeated was 344 ± 28.8 μg/cm(2) with a lag time of 2.3 ± 1.3 h.

CONCLUSION

The hydrogel formulation containing PFD-loaded liposomes can be developed as a potential transdermal delivery system.

A review of TTS – development, types and preparations

Transdermal Therapeutic Systems (TTS) are elastic multi-layer patches applied to the skin in order to deliver active substances into the bloodstream. One advantage of a transdermal drug delivery route over other types of medication delivery is that the patch provides a noninvasive therapy, longer duration of drug activity, and improves most of bioavailability. TTS consist of a backing layer, a drug, an adhesive, and a release liner. TTS can be divided into five basic types of systems: reservoir, matrix, microreservoir, single-layer drug in adhesive, and multi-layer drug in adhesive. In order to improve the penetration of drugs through the skin, passive and active methods are used. The researchers are constantly developing new methods of improving the delivery of drugs applied by transdermal route.