Niosome-Encapsulated Gentamicin for Ophthalmic Controlled Delivery

The objective of the present research was to investigate the feasibility of using non-ionic surfactant vesicles (niosomes) as carriers for the ophthalmic controlled delivery of a water soluble local antibiotic; gentamicin sulphate. Niosomal formulations were prepared using various surfactants (Tween 60, Tween 80 or Brij 35), in the presence of cholesterol and a negative charge inducer dicetyl phosphate (DCP) in different molar ratios and by employing a thin film hydration technique. The ability of these vesicles to entrap the studied drug was evaluated by determining the entrapment efficiency %EE after centrifugation and separation of the formed vesicles. Photomicroscopy and transmission electron microscopy as well as particle size analysis were used to study the formation, morphology and size of the drug loaded niosomes. Results showed a substantial change in the release rate and an alteration in the %EE of gentamicin sulphate from niosomal formulations upon varying type of surfactant, cholesterol content and presence or absence of DCP. In-vitro drug release results confirmed that niosomal formulations have exhibited a high retention of gentamicin sulphate inside the vesicles such that their in vitro release was slower compared to the drug solution. A preparation with 1:1:0.1 molar ratio of Tween 60, cholesterol and DCP gave the most advantageous entrapment (92.02% ± 1.43) and release results (Q_8h = 66.29% ± 1.33) as compared to other compositions. Ocular irritancy test performed on albino rabbits, showed no sign of irritation for all tested niosomal formulations.     

Investigation of Formulation Variables and Excipient Interaction on the Production of Niosomes

The aim of this study was to investigate the effects of formulation and process variables on the properties of niosomes formed from Span 40 as nonionic surfactant. A variety of formulations encapsulating Paclitaxel, a hydrophobic model drug, were prepared using different dicetyl phosphate (DCP) and Span 40-cholesterol (1:1) amounts. Formulations were optimized by multiple regression analysis to evaluate the changes on niosome characteristics such as entrapment efficiency, particle size, polydispersity index, zeta potential and in vitro drug release. Multiple regression analysis revealed that as Span 40-cholesterol amounts in the formulations were increased, zeta potential and percent of drug released at 24th hour were decreased. Besides, DCP was found to be effective on increasing niosome size. As a process variable, the effect of sonication was observed and findings revealed an irreversible size reduction on Span 40 niosomes after probe sonication. Monodisperse small sized (133 ± 6.01 nm) Span 40 niosomes entrapping 98.2% of Paclitaxel with a weight percentage of 3.64% were successfully prepared. The drug–excipient interactions in niosomes were observed by differential scanning calorimetry and X-ray powder diffraction analysis. Both techniques suggest the conversion of PCTs’ crystal structure to amorphous form. The thermal analyses demonstrate the high interaction between drug and surfactant that explains high entrapment efficiency. After 3-month storage, niosomes preserved their stability in terms of drug amount and particle size. Overall, this study showed that Span 40 niosomes with desired properties can be prepared by changing the content and production variables.Key words: drug delivery systems, drug release, multiple regression, niosomes, paclitaxel     

Diacerein niosomal gel for topical delivery: development,in vitro and in vivo assessment

The purpose of this study was to load diacerein (DCR) in niosomes by applying response surface methodology and incorporate these niosomes in gel base for topical delivery. Box–Behnken design was used to investigate the effect of charge-inducing agent (X₁), surfactant HLB (X₂) and sonication time (X₃) on the vesicle size (Y₁), entrapment efficiency (Y₂) and cumulative drug released (Y₃). DCR niosomal formulations were prepared by thin film hydration method. The optimized formula was incorporated in different gel bases. DCR niosomal gels were evaluated for homogeneity, rheological behavior; in vitro release and pharmacodynamic activity by carrageenan-induced hind paw edema method in the rat compared with DCR commercial gel. The results revealed that the mean vesicle sizes of the prepared niosomes ranged from 7.33 to 23.72?µm and the entrapment efficiency ranged from 9.52% to 58.43% with controlled release pattern over 8?h. DCR niosomal gels exhibited pseudoplastic flow with thixotropic behavior. The pharmacodynamic activity of DCR niosomal gel in 3% HPMC showed significant, 37.66%, maximum inhibition of edema size in comparison with 20.83% for the commercial gel (p?相似文献   

Dual-Prevention for UV-Induced Skin Damage: Incorporation of Melatonin-Loaded Elastic Niosomes into Octyl Methoxycinnamate Pickering Emulsions

Incorporation of antioxidants into sunscreens is a logical approach, yet co-delivery of them with UV filters is a challenge. Here, we purposed a combination therapy, in which the chemical UV filter, octyl methoxycinnamate, was accumulated on upper skin while the antioxidant, melatonin, can penetrate deeper layers to show its effects. Melatonin-loaded elastic niosomes and octyl methoxycinnamate Pickering emulsion were prepared separately. Lyophilized elastic niosomes were dispersed into the Pickering emulsion to prepare the proposed combination formulation. The characterization studies of the formulations revealed that elastic niosomes can be prepared with tunable nanometer sizes, whereas Pickering emulsions can encapsulate the UV filter in micrometer-sized droplets. Melatonin-loaded elastic niosomes prepared with Tween80/Span80 mixture were 146 nm with a PI of 0.438, and 58.42% entrapment efficiency was achieved. The mean diameter size of the combination formulation was 27.8 μm. Ex vivo permeation studies revealed that 7.40% of octyl methoxycinnamate and 58% of melatonin were permeated through the rat skin while 27.6% octyl methoxycinnamate and 37% of melatonin accumulated in the skin after 24 h. Cell culture studies with real-time cell analyzer showed that the proposed formulation consist of melatonin-loaded elastic niosomes and octyl methoxycinnamate Pickering emulsion had no negative effect on the cell proliferation and viability. According to α,α-diphenyl-β-picrylhydrazyl free radical scavenging method, the proposed formulation showed as high antioxidant activity as melatonin itself. It is concluded that the proposed formulation would be a promising dual therapy for UV-induced skin damage with co-delivery strategy.     

Vancomycin-Eluting Niosomes: A New Approach to the Inhibition of Staphylococcal Biofilm on Abiotic Surfaces

A new vancomycin (VCM)-eluting mixed bilayer niosome formulation was evaluated for the control of staphylococcal colonization and biofilm formation on abiotic surfaces, a niosome application not explored to date. Cosurfactant niosomes were prepared using a Span 60/Tween 40/cholesterol blend (1: 1: 2). Tween 40, a polyethoxylated amphiphile, was included to enhance VCM entrapment and confer niosomal surface properties precluding bacterial adhesion. VCM-eluting niosomes showed good quality attributes including relatively high entrapment efficiency (～50%), association of Tween 40 with vesicles in a constant proportion (～87%), biphasic release profile suitable for inhibiting early bacterial colonization, and long-term stability at 4°C for a 12-month study period. Niosomes significantly enhanced VCM activity against planktonic bacteria of nine staphylococcal strains. Using microtiter plates as abiotic surface, VCM-eluting niosomes proved superior to VCM in inhibiting biofilm formation, eradicating surface-borne biofilms, inhibiting biofilm growth, and interfering with biofilm induction by VCM subminimal inhibitory concentrations. Data suggest dual functionality of cosurfactant VCM-eluting niosomes as passive colonization inhibiting barrier and active antimicrobial-controlled delivery system, two functions recognized in infection control of abiotic surfaces and medical devices.     

Metformin hydrochloride and wound healing: from nanoformulation to pharmacological evaluation

Abstract

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.     

Preparation and characterization of propylthiouracil niosomes

Propylthiouracil, a lyophobic drug with an antiproliferative activity, was formulated into niosomes using various classes of nonionic surfactants. Feasibility of vesicle formation by the sonication method was evaluated. Size and size distribution was measured by laser diffraction. Entrapment and drug release over 24 h were monitored by UV spectrophotometric method at 275 nm. The results revealed that niosomes readily formed from various compositions of nonionic surfactant and cholesterol, with or without a stabilizer. Entrapment of PTU in niosomes depended on bilayer composition. The release of PTU from all niosomal formulations studied was retarded and followed the first-order kinetics. Degree of slow release had a negative correlation with drug entrapment. The release rate also depended on the physical state of the bilayer. The results of this study indicate that PTU niosomes were able to control the release of PTU and might be of value to develop further into topical formulations.     

Preparation and Characterization of Propylthiouracil Niosomes

Propylthiouracil, a lyophobic drug with an antiproliferative activity, was formulated into niosomes using various classes of nonionic surfactants. Feasibility of vesicle formation by the sonication method was evaluated. Size and size distribution was measured by laser diffraction. Entrapment and drug release over 24 h were monitored by UV spectrophotometric method at 275 nm. The results revealed that niosomes readily formed from various compositions of nonionic surfactant and cholesterol, with or without a stabilizer. Entrapment of PTU in niosomes depended on bilayer composition. The release of PTU from all niosomal formulations studied was retarded and followed the first-order kinetics. Degree of slow release had a negative correlation with drug entrapment. The release rate also depended on the physical state of the bilayer. The results of this study indicate that PTU niosomes were able to control the release of PTU and might be of value to develop further into topical formulations.     

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

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

Development and Characterization of Mixed Niosomes for Oral Delivery Using Candesartan Cilexetil as a Model Poorly Water-Soluble Drug

The aim of this study was to prepare candesartan cilexetil-loaded niosomes and mixed niosomes to enhance the aqueous solubility of the drug, thus improving its oral bioavailability. The formulations were prepared using various types and combinations of surfactants, copolymers, and charge-inducing agents. The candesartan cilexetil entrapment efficiency, particle size, and zeta potential of these niosomes varied within the range of 99.06 ± 1.74 to 36.26 ± 2.78, 157.3 ± 3.3 to 658.3 ± 12.7 nm, and −14.7 ± 2.8 to −44.5 ± 1.5 mV, respectively. The in vitro drug release from niosomes was improved after niosomal entrapment compared to pure candesartan cilexetil. The sedimentation behavior study and formulation stability tests against bile salt revealed that mixed niosomes prepared by combining Span 60 and Pluronic P85 demonstrated better stability. The differential scanning calorimetry analysis showed the conversion of crystal structure of candesartan cilexetil to the soluble amorphous form after niosomal encapsulation which induced the drug release. Consequently, oral drug delivery by Span 60/Pluronic P85-mixed niosomes seems feasible due to enhanced drug release and stability.KEY WORDS: in vitro drug release, niosomes, oral drug delivery, stability, surfactants     

Ultrasonic Processing Technique as a Green Preparation Approach for Diacerein-Loaded Niosomes

In this study, the feasibility of ultrasonic processing (UP) technique as green preparation method for production of poorly soluble model drug substance, diacerein, loaded niosomes was demonstrated. Also, the effects of different surfactant systems on niosomes’ characteristics were analyzed. Niosomes were prepared using both the green UP technique and traditional thin-film hydration (TFH) technique, which requires the use of environmentally hazardous organic solvents. The studied surfactant systems were Span 20, Pluronic L64, and their mixture (Span 20 and Pluronic L64). Both the production techniques produced well-defined spherical vesicles, but the UP technique produced smaller and more monodisperse niosomes than TFH. The entrapment efficiencies with the UP method were lower than with TFH, but still at a feasible level. All the niosomal formulations released diacerein faster than pure drug, and the drug release rates from the niosomes produced by the UP method were higher than those from the TFH-produced niosomes. With UP technique, the optimum process conditions for small niosomal products with low PDI values and high entrapment efficiencies were obtained when 70% amplitude and 45-min sonication time were used. The overall results demonstrated the potency of UP technique as an alternative fast, cost-effective, and green preparation approach for production of niosomes, which can be utilized as drug carrier systems for poorly soluble drug materials.     

Sorbitan ester niosomes for topical delivery of rofecoxib

The aim of the present investigation is to encapsulate rofecoxib in niosomes and incorporate the prepared niosomes into dermal gel base for sustained therapeutic action. Niosomes were prepared by lipid film hydration technique and were analyzed for size, entrapment efficiency and drug retention capacity. Niosomal vesicles were then incorporated into blank carbopol gel to form niosomal gel. The in vitro permeation study across pig skin was performed using Keshary-Chien glass diffusion cell. The size and entrapment efficiency of the niosomal vesicles increased with gradual increase in HLB value of nonionic surfactants used. Maximum drug entrapment was observed with Span 20 with HLB value of 8.6 and drug leakage from vesicles was less at refrigerated condition than at the room temperature. Higher proportion of cholesterol made the niosomal formulation more stable with high drug retention properties. The niosomal gel showed a prolong drug release behavior compared to plain drug gel. Differential scanning calorimetric study of drug loaded gel and pig skin after permeation study confirmed inertness of carbopol gel base toward rofecoxib and absence of drug metabolism in the skin during permeation study, respectively. The niosomal formulations were successfully prepared by lipid film hydration technique using cholesterol and Span as nonionic surfactant. Presence of cholesterol made niosomes more stable with high drug entrapment efficiency and retention properties. The lower flux value of niosomal gel as compared to plain drug gel across pig skin assured the prolong drug release behavior with sustained action.     

Oral delivery of allopurinol niosomes in treatment of gout in animal model

Context: Gout is a painful disorder which does not have an efficient delivery system for its treatment.

Objective: Development and in vitro, in vivo evaluation of allopurinol-loaded nonionic surfactant-based niosomes was envisaged.

Materials and methods: Niosomes were prepared with Span 20 and Tween 20 (1:1 molar ratio) using ether injection method. The formulations were screened for entrapment efficiency, particle size analysis, zeta potential, release kinetics, in vivo activity, and stability studies.

Result: Stable, spherical vesicles of average particle size 304?nm with zeta-potential and entrapment efficiency of 22.2?mV and 79.44?±?0.02%, respectively, were produced. In vitro release study revealed 82.16?±?0.04% release of allopurinol within 24?h. The niosomal formulation was further evaluated for its antigout potential in monosodium urate (MSU) crystal induced gout animal model. The formulation demonstrated significant uric acid level reduction and enhanced antigout activity when compared with the pure allopurinol.

Discussion: The better antigout activity displayed by niosomal formulation could be attributed to sustained release of drug, higher drug solubility within biological fluids, better membrane interaction, smaller size, and presence of cholesterol and surfactant.

Conclusions: This study reveals that niosomes can be an efficient delivery system for the treatment of gout.     

Influence of a niosomal formulation on the oral bioavailability of acyclovir in rabbits

The purpose of this research was to prepare acyclovir niosomes in a trial to improve its poor and variable oral bioavailability. The nonionic surfactant vesicles were prepared by the conventional thin film hydration method. The lipid mixture consisted of cholesterol, span 60, and dicetyl phosphate in the molar ratio of 65:60:5, respectively. The percentage entrapment was approximately 11% of acyclovir used in the hydration process. The vesicles have an average size of 0.95 microm, a most probable size of 0.8 microm, and a size range of 0.4 to 2.2 microm. Most of the niosomes have unilamellar spherical shape. In vitro drug release profile was found to follow Higuchi's equation for free and niosomal drug. The niosomal formulation exhibited significantly retarded release compared with free drug. The in vivo study revealed that the niosomal dispersion significantly improved the oral bioavailability of acyclovir in rabbits after a single oral dose of 40 mg kg(-1). The average relative bioavailability of the drug from the niosomal dispersion in relation to the free solution was 2.55 indicating more than 2-fold increase in drug bioavailability. The niosomal dispersion showed significant increase in the mean residence time (MRT) of acyclovir reflecting sustained release characteristics. In conclusion, the niosomal formulation could be a promising delivery system for acyclovir with improved oral bioavailability and prolonged drug release profiles.     

A facile approach to manufacturing non-ionic surfactant nanodipsersions using proniosome technology and high-pressure homogenization

Abstract

In this study, a niosome nanodispersion was manufactured using high-pressure homogenization following the hydration of proniosomes. Using beclometasone dipropionate (BDP) as a model drug, the characteristics of the homogenized niosomes were compared with vesicles prepared via the conventional approach of probe-sonication. Particle size, zeta potential, and the drug entrapment efficiency were similar for both size reduction mechanisms. However, high-pressure homogenization was much more efficient than sonication in terms of homogenization output rate, avoidance of sample contamination, offering a greater potential for a large-scale manufacturing of noisome nanodispersions. For example, high-pressure homogenization was capable of producing small size niosomes (209?nm) using a short single-step of size reduction (6?min) as compared with the time-consuming process of sonication (237?nm in >18?min) and the BDP entrapment efficiency was 29.65%?±?4.04 and 36.4%?±?2.8. In addition, for homogenization, the output rate of the high-pressure homogenization was 10?ml/min compared with 0.83?ml/min using the sonication protocol. In conclusion, a facile, applicable, and highly efficient approach for preparing niosome nanodispersions has been established using proniosome technology and high-pressure homogenization.     

Preparation and in vitro evaluation of liposomal/niosomal delivery systems for antifungal drug clotrimazole

Clotrimazole, an imidazole derivative antifungal agent is widely used for the treatment of mycotic infections of the genitourinary tract. In order to develop alternative formulation for the vaginal administration of clotrimazole to provide sustained and controlled release of appropriate drug for local vaginal therapy, liposomes/niosomes were evaluated as delivery vehicles. To optimize the preparation of liposomes/niosomes with regards to size and entrapment efficiency, multilamellar liposomes/niosomes containing drug were prepared by lipid hydration method. The ability of the systems to deliver clotrimazole into and through the mucosa was evaluated in vitro using rabbit vaginal mucosa with vertical Franz diffusion cells. The in vitro permeation data showed that the liposomes/niosomes system increased the clotrimazole total penetration through the vaginal mucosa by 1.6, 1.5-fold, the accumulation of clotrimazole into the mucosa was increased by 3.1, 2.3-fold, respectively, as compared with control during 24 hr. These results suggest that the studied liposomes/niosomes systems may be appropriate vesicles for the vaginal mucosa delivery of clotrimazole for local vaginal therapy.     

Prolonged release biodegradable vesicular carriers for rifampicin--formulation and kinetics of release

An attempt has been made to design suitable liposome and niosome-encapsulated drug delivery system for rifampicin and evaluated the same in vitro and in vivo. A modified lipid layer hydration method was employed to prepare these vesicular carriers. The formulated systems were characterized in vitro for size distribution analysis, drug entrapment, drug release profiles and vesicular stability at different conditions of storage. In vivo drug kinetics was evaluated in normal, healthy albino rats for niosomal formulation upon subcutaneous injection and various pharmacokinetic parameters were determined. Niosomes and liposomes exhibited mean diameter of 9.73 and 11.87 microns with entrapment efficiencies of 30.5 and 34.2% respectively. Both the products exhibited sustained release characteristics in vitro with zero order drug release kinetics up to initial 10 hr. Stability evaluation indicated that both formulations were not significantly leaky over a period of one month. Niosomal formulation elevated plasma elimination half life and decreased elimination rate constants for rifampicin in vivo suggested that encapsulation retarded the removal of the drug from circulation compared to free drug due to slow drug release into systemic circulation. A five-fold increase in the area under plasma rifampicin concentration-time curve for niosomal rifampicin as compared to free drug indicated better bioavailability of encapsulated drug. It is evident from this study that niosomes and liposomes could be promising delivery systems for rifampicin with prolonged drug release profiles and reasonably good stability characteristics.     

Topical Delivery of Fenoprofen Calcium <Emphasis Type="Italic">via</Emphasis> Elastic Nano-vesicular Spanlastics: Optimization Using Experimental Design and <Emphasis Type="Italic">In Vivo</Emphasis> Evaluation

The aim of this study was to investigate the potential of surfactant-based nanovesicular system (spanlastics) for topical delivery of fenoprofen calcium (FPCa) to eliminate its oral gastrointestinal adverse effects. FPCa-loaded spanlastics were prepared by thin film hydration (TFH) technique according to a full factorial design to investigate the influence of formulation variables on the drug entrapment efficiency (%EE), particle size (PS), deformability index (DI), and the % drug released after 24 h through the cellulose membrane (Q24h) using Design-Expert® software. The optimized formula (composed of Span 60 and Tween 60 as an edge activator at weight ratio of 8: 2 in presence of Transcutol P as a cosolvent in the hydration media) exhibited the highest %EE (49.91 ± 2.60%), PS of 536.1 ± 17.14 nm, DI of 5.07 ± 0.06 g, and Q24h of 61.11 ± 2.70%; it was also characterized for morphology and physical stability. In vitro release study of FPCa-loaded spanlastic gel and conventional FPCa gel through a synthetic membrane and hairless rat skin were evaluated. The skin permeation study revealed that spanlastic gel exhibited both consistent and prolonged action. Finally, the % inhibition of carrageenan-induced rat paw edema of spanlastic gel was three times higher than the conventional FPCa gel after 24 h. In conclusion, spanlastic-based gel could be a great approach for improving topical delivery of fenoprofen calcium, providing both prolonged and enhanced anti-inflammatory activity in the treatment of arthritis.     

Progesterone-loaded nanosized transethosomes for vaginal permeation enhancement: formulation,statistical optimization,and clinical evaluation in anovulatory polycystic ovary syndrome

Bio-identical progesterone (PRG) is an exogenous female steroidal hormone which is used for treatment of polycystic ovary syndrome (PCOS). However, it suffers from poor bioavailability due to hepatic metabolism and poor solubility. The target of this work was to evaluate and statistically optimize PRG-loaded nanovesicle transethosomes (NVTEs) based in mucoadhesive gel for transvaginal delivery of PRG as potential luteal-phase support. A 2⁴ full factorial design was used to explore the effect of phosphatidylcholine (PC), Tween 80, cetyltrimethyl ammonium bromide and ethanol concentration on particle size, entrapment efficiency (EE%), % in vitro PRG release after 24?h and transvaginal flux. PRG-loaded NVTEs were prepared by injection sonication method. The results revealed that the mean particle sizes ranged from 133.3?±?3.42 to 349.5?±?1.24?nm, zeta potential ranged from –23.5?±?3.84 to +74.6?±?4.97?mV, EE% ranged from 87.93?±?3.58 to 97.05?±?2.61%, % PRG release ranged from 50.9?±?2.75 to 90.69?±?2.07 and transvaginal flux ranged from 0.274?±?0.03 to 0.531?±?0.04?mg/cm²/h. The optimized formulation was subjected to transmission electron microscope for morphological examination and then incorporated in the mucoadhesive vaginal gel using Carbopol 974, hydroxyl propyl methylcellulose and sodium alginate. The optimized formulation was clinically studied in anovulatory PCOS and showed a significant increase in the serum PRG, endometrial thickness, echogenicity degree and the pregnancy rate. Briefly, PRG-loaded NVTEs vaginal gel might be a promising formulation for luteal phase support and increase pregnancy rate in anovulatory PCOS.