Double Emulsion Solvent Evaporation Method Research Articles

Co-delivery of doxycycline and rifampicin using CdTe-labeled poly (lactic-co-glycolic) acid for treatment of Brucella melitensis infection

Brucellosis poses a significant challenge in the medical field as a systemic infection with a propensity for relapse. This study presented a novel approach to brucellosis treatment, enhancing the efficacy of doxycycline and rifampicin through the use of poly (lactic-co-glycolic) acid coupled with cadmium-telluride quantum dots (Dox-Rif-PLGA@CdTe). The double emulsion solvent evaporation method was employed to prepare Dox-Rif-PLGA@CdTe. The study scrutinized the physicochemical attributes of these nanoparticles. The impact of antibiotic-loaded nanoparticles on Brucella melitensis was evaluated through well diffusion, minimum inhibitory concentration (MIC), and cell culture. The chemical analysis results demonstrated a possibility of chemical reactions occurring among the constituents of nanoparticles. Assessments using the well diffusion and MIC methods indicated that the impact of free drugs and nanoparticles on bacteria was equivalent. However, the drug-loaded nanoparticles significantly decreased the colony-forming units (CFUs) within the cell lines compared to free drugs. In conclusion, the synthesis of nanoparticles adhered to environmentally friendly practices and demonstrated safety. The sustained drug release over 100 h facilitated drug accumulation at the bacterial site, resulting in a heightened therapeutic effect on B. melitensis and improved outcomes in brucellosis treatment. The application of these synthesized nanodrugs exhibited promising therapeutic potential.

Aurothioglucose encapsulated nanoparticles fostered neuroprotection in streptozotocin-induced Alzheimer’s disease

Alzherimer’s disease (AD) is an age-dependent ubiquitous ailment worldwide with limited therapies that only alleviate the symptoms of AD but do not cure them entirely because of the restricted blood–brain barrier passage of the drug. Hence with new advanced technology, nanoparticles can offer an opportunity as the active candidate to overcome the above limitations. Aurothioglucose, a synthetic glucose derivative of the gold compound, has been clinically proven to be an effective anti-inflammatory drug for rheumatic arthritis. Recently, several scientific groups have developed gold nanoparticle preparations and tested them for the treatment of dementia. This study was planned to prepare the PLGA nanoparticles of aurothioglucose (ATG) and check the neuroprotective potential against STZ-induced AD in rats. The nanoparticles were prepared using the double emulsion solvent evaporation method and characterized for various parameters such as drug-excipient interaction, particle size, zeta potential, and morphology. Then, rats were injected STZ (3 mg/kg/i.c.v., days 1 and 3) and ATG (5 and 10 mg/kg/s.c.), ATG NPs (2.5 and 5 mg/kg/s.c.) and donepezil (2 mg/kg/p.o) from 15th to 29th day. Behavior parameters were performed using an actophotometer, MWM, and ORT. On the 30th day, all the animals were sacrificed, and the brains were isolated for estimating biochemical, neurochemical, and proinflammatory markers. It was observed that ATG NPs significantly restored all behavior and neurotransmitter alterations caused by STZ. Also, it increased antioxidant levels and decreased inflammatory cytokines significantly, then ATG alone. Thus, the study suggests that ATG loaded PLGA NPs could be used as a novel therapeutic strategy to slow the process of AD.

An enhanced cardio-protective effect of nanoparticles loaded with active components from Polygonum orientale L. against isoproterenol-induced myocardial ischemia in rats

In this study, nanoparticles loaded with active components from Polygonum orientale L. (PO), a traditional Chinese herb known for its anti-myocardial ischemic properties, were investigated for cardio-protective properties. Specifically, OVQ-Nanoparticles (OVQ-NPs) with Orientin (Ori), Vitexin (Vit), and Quercetin (Que) was obtained by double emulsion-solvent evaporation method. The OVQ-NPs exhibited a spherical shape, with a uniform size distribution of 136.77 ± 3.88 nm and a stable ζ-potential of −13.40 ± 2.24 mV. Notably, these nanoparticles exhibited a favorable sustained-release characteristic, resulting in an extended circulation time within the living organism. Consequently, the administration of these nanoparticles resulted in significant improvements in electrocardiograms and heart mass index of myocardial ischemic rats induced by isoproterenol, as well as decreased serum levels of CK, LDH, and AST. Furthermore, the results of histopathological examination, such as H&E staining and TUNEL staining, confirmed a reduced level of cardiac tissue pathology and apoptosis. Moreover, the quantification of biochemical indicators (SOD, MDA, GSH, NO, TNF-α, and IL-6) demonstrated that OVQ-NPs effectively mitigated myocardial ischemia by regulating oxidative stress and inflammatory pathways. In conclusion, OVQ-NPs demonstrate promising therapeutic potential as an intervention for myocardial ischemia, providing a new perspective on traditional Chinese medicine treatment in this area.

Levofloxacin loaded chitosan and poly-lactic-co-glycolic acid nano-particles against resistant bacteria: Synthesis, characterization and antibacterial activity

BackgroundWith the global increase in antibacterial resistance, the challenge faced by developing countries is to utilize the available antibiotics, alone or in combination, against resistant bacterial strains. We aimed to encapsulate the levofloxacin (LVX) into polymeric nanoparticles using biodegradable polymers i.e. Chitosan and PLGA, estimating their physicochemical characteristics followed by functional assessment as nanocarriers of levofloxacin against the different resistant strains of bacteria isolated from biological samples collected from tertiary care hospital in Lahore, Pakistan. MethodsLVX-NPs were synthesized using ion gelation and double emulsion solvent-evaporation method employing chitosan (CS) and poly-lactic-co-glycolic acid (PLGA), characterized via FTIR, XRD, SEM, and invitro drug release studies, while antibacterial activity was assessed using Kirby-Bauer disc-diffusion method. ResultsData revealed that the levofloxacin-loaded chitosan nanoparticles showed entrapment efficiency of 57.14% ± 0.03 (CS-I), 77.30% ± 0.08(CS-II) and 87.47% ± 0.08 (CS-III). The drug content, particle size, and polydispersity index of CS-I were 52.22% ± 0.2, 559 nm ± 31 nm, and 0.030, respectively, whereas it was 66.86% ± 0.17, 595 nm ± 52.3 nm and 0.057, respectively for CS-II and 82.65% ± 0.36, 758 nm ± 24 nm and 0.1, respectively for CS-III. The PLGA-levofloxacin nanoparticles showed an entrapment efficiency of 42.80% ± 0.4 (PLGA I) and 23.80% ± 0.4 (PLGA II). The drug content, particle size and polydispersity index of PLGA-I were 86% ± 0.21, 92 nm ± 10 nm, and 0.058, respectively, whereas it was 52.41% ± 0.45, 313 nm ± 32 nm and 0.076, respectively for PLGA-II. The XRD patterns of both polymeric nanoparticles showed an amorphous nature. SEM analysis reflects the circular-shaped agglomerated nanoparticles with PLGA polymer and dense spherical nanoparticles with chitosan polymer. The in-vitro release profile of PLGA-I nanoparticles showed a sustained release of 82% in 120 h and it was 58.40% for CS-III. Both types of polymeric nanoparticles were found to be stable for up to 6 months without losing any major drug content. Among the selected formulations, CS-III and PLGA-I, CS-III had better antibacterial potency against gram+ve and gram-ve bacteria, except for K. pneumonia, yet, PLGA-I demonstrated efficacy against K. pneumonia as per CSLI guidelines. All formulations did not exhibit any signs of hemotoxicity, nonetheless, the CS-NPs tend to bind on the surface of RBCs. ConclusionThese data suggested that available antibiotics can effectively be utilized as nano-antibiotics against resistant bacterial strains, causing severe infections, for improved antibiotic sensitivity without compromising patient safety.

Polymeric Propranolol Nanoparticles for Intraocular Delivery: Formulation, Characterization, and Vitreous Pharmacokinetics.

Recent studies have reported the promising effect of intravitreal propranolol on retinal neovascularization. However, rapid clearance and short half-life of the drug in the vitreous are the main drawbacks of this therapeutic approach. This study investigates the extension of the residence time of propranolol in the vitreous by polymeric nanoparticles (NPs) with the prospect of improving choroidal neovascularization treatment. The poly (lactic-co-glycolic) acid (PLGA) NPs were fabricated by a modified double emulsion solvent evaporation method and the obtained NPs were characterized for their size, poly dispersity index (PDI), and surface image. The in vitro release, cell cytotoxicity, and uptake of NPs were also evaluated. To investigate the effect of the vitreous pharmacokinetic drug loaded NPs versus that of the free propranolol, they were intravitreally injected into the rabbits' eyes and the drug vitreous concentrations in defined intervals were analyzed by high performance liquid chromatography (HPLC). The spherical NPs with about 230 nm size, and almost 10% drug loading were obtained. Based on the 3-(4, 5-Dimethylthiazol-2-Yl)-2, 5-Diphenyltetrazolium Bromide (MTT) outcomes, 30 µg/ml of propranolol was considered as the guide dosage in the intravitreal injection. Confocal microscopy images verified the presence of labeled NPs in the posterior segment after five days of receiving the injection. In vivo assay revealed that the vanishing rate of propranolol in rabbits treated with propranolol NPs was reduced at twice the rate as compared to that of the vanishing rate experienced with only the free drug. PLGA NPs can prolong the existence of propranolol in both vitreous and posterior ocular tissues, and thus, may provide an effective approach in treatment of posterior segment neovascularization.

Polylactic Glycolic Acid-Mediated Delivery of Plectasin Derivative NZ2114 in Staphylococcus epidermidis Biofilms.

Antimicrobial peptides (AMPs) are antibiotic candidates; however, their instability and protease susceptibility limit clinical applications. In this study, the polylactic acid-glycolic acid (PLGA)-polyvinyl alcohol (PVA) drug delivery system was screened by orthogonal design using the double emulsion-solvent evaporation method. NZ2114 nanoparticles (NZ2114-NPs) displayed favorable physicochemical properties with a particle size of 178.11 ± 5.23 nm, polydispersity index (PDI) of 0.108 ± 0.10, ζ potential of 4.78 ± 0.67 mV, actual drug-loading rate of 4.07 ± 0.37%, encapsulation rate of 81.46 ± 7.42% and cumulative release rate of 67.75% (120 h) in PBS. The results showed that PLGA encapsulation increased HaCaT cell viability by 20%, peptide retention in 50% serum by 24.12%, and trypsin tolerance by 4.24-fold. Meanwhile, in vitro antimicrobial assays showed that NZ2114-NPs had high inhibitory activity against Staphylococcus epidermidis (S. epidermidis) (4-8 μg/mL). Colony counting and confocal laser scanning microscopy (CLSM) confirmed that NZ2114-NPs were effective in reducing the biofilm thickness and bacterial population of S. epidermidis G4 with a 99% bactericidal rate of persister bacteria, which was significantly better than that of free NZ2114. In conclusion, the results demonstrated that PLGA nanoparticles can be used as a reliable NZ2114 delivery system for the treatment of biofilm infections caused by S. epidermidis.

Development of novel polymer haemoglobin based particles as an antioxidant, antibacterial and an oxygen carrier agents

This innovative work aims to develop highly biocompatible and degradable nanoparticles by encapsulating haemoglobin (Hb) within poly-ε-caprolactone for novel biomedical applications. We used a modified double emulsion solvent evaporation method to fabricate the particles. A Scanning electron microscope (SEM) characterized them for surface morphology. Fourier Transform Infrared Spectroscopy (FTIR) and Ultraviolet–visible spectroscopies (UV–visible) elucidated preserved chemical and biological structure of encapsulated haemoglobin. The airproof equilibrium apparatus obtained the oxygen-carrying capacity and P50 values. The DPPH assay assessed free radical scavenging potential. The antibacterial properties were observed using four different bacterial strains by disk diffusion method. The MTT assay investigates the cytotoxic effects on mouse fibroblast cultured cell lines (L-929). The MTT assay showed that nanoparticles have no toxicity over large concentrations. The well-preserved structure of Hb within particles, no toxicity, high oxygen affinity, P50 value, and IC50 values open the area of new research, which may be used as artificial oxygen carriers, antioxidant, and antibacterial agents, potential therapeutic agents as well as drug carrier particles to treat the cancerous cells. The novelty of this work is the antioxidant and antibacterial properties of developed nanoparticles are not been reported yet. Results showed that the prepared particles have strong antioxidant and antibacterial potential.

Nanoparticle‐based sustained drug delivery for the treatment of ocular neovascular diseases

Aims/Purpose: Nanoparticles have shown great potential as a drug delivery system for the treatment of neovascular ocular diseases characterized by the growth of abnormal blood vessels in the retina. The current standard of therapy for neovascular ocular diseases involves administering monoclonal antibody‐based anti‐VEGF drugs via intravitreal injections on a periodic basis. The short half‐lives of these drugs necessitate frequent injections, which can limit the effectiveness of the treatments. Hence, there is a need to develop new approaches for enhanced bioavailability and sustained and long‐lasting delivery of anti‐VEGF drugs. The aim of this study was to utilize poly (glycerol sebacate) (PGS) nanoparticles to achieve an extended release of anti‐VEGF (anti‐vascular endothelial growth factor) drugs, with the objective of reducing the frequency of intravitreal injections required for treatment.Methods: Double emulsion solvent evaporation method was utilized for the synthesis of PGS nanoparticles. Nanoparticle size and polydispersity index (PDI) were determined with dynamic light scattering method.Results: Nanoparticles were synthesized with a size of approximately 150 nm and PDI less than 0.3. The encapsulation efficiency of nanoparticles loaded with anti‐VEGF drugs was found to be 74%. The 30% drug release from nanoparticles in the first 2 months indicates that nanoparticles are a promising candidate for sustained drug release applications. Cell‐viability studies showed that anti‐VEGF drug‐loaded nanoparticles did not exhibit toxicity to ARPE‐19 cells, but they did exhibit anti‐angiogenesis properties by inhibiting the growth of HUVEC cells in a concentration‐dependent manner.Conclusions: The development of new‐generation materials for the storage and preservation of anti‐VEGF drugs, as well as their enhancement with prolonged release, will considerably improve the efficacy of long‐term treatment strategies for ocular neovascular diseases.

Preparation, Characterization, and Release Profile Study of Vincristine Sulfate-loaded Polycaprolactone Nanoparticles

Background: Vincristine sulfate is commonly used to treat different types of cancers. However, its effectiveness is hindered by undesirable side effects, which significantly limit its applications in medicine. Objective: This study aims to prepare vincristine nanoparticles, in order to develop a promising approach for cancer therapy. Methods: Vincristine nanoparticles were prepared by utilizing polycaprolactone as a carrier through the double emulsion method. The morphological characteristics and particle size of the vincristine nanoparticles were examined. The surface charge and average dynamic size, encapsulation efficiency in addition to release profile study were also evaluated. Results: Dynamic Light Scattering confirmed the small size of nanoparticles (~200 nm). SEM showed spherical-shaped nanoparticles with smooth surfaces, and the polydispersity index values of the prepared nanoparticles were below 0.5 in all preparations. The zeta potential of the nanoparticles was found to be negative, which can be attributed to the presence of carboxylic groups in the PCL polymer, The encapsulation efficiency of Vincristine-loaded nanoparticles (NPs) varied from 36% to 57% for all the prepared NPs with varying amounts of PCL. The release profile demonstrated a prolonged release of Vincristine from the nanoparticles compared to the Vincristine solution. Conclusion: The double emulsion solvent evaporation method was used successfully to prepare vincristine- loaded PCL nanoparticles, which suggests that nanoscale carriers hold promise as effective vehicles for delivering chemotherapeutic agents in the treatment of cancer.

Aqueous remote loading of model cationic peptides in uncapped poly(lactide-co-glycolide) microspheres for long-term controlled release.

Remote loading microencapsulation of peptides into polymer microspheres without organic solvent represents a promising alternative to develop long-acting release depots relative to conventional encapsulation methods. Here, we formulated drug-free microspheres from two kinds of uncapped poly(lactide-co-glycolides) (PLGAs), i.e., ring-opening polymerized Expansorb® DLG 50-2A (50/50, 11.2kDa) and Expansorb® DLG 75-2A (75/25, 9.0kDa), and evaluated their potential capacity to remote-load and control the release of two model peptides, leuprolide and octreotide. Degradation and erosion kinetics, release mechanism, and storage stability was also assessed. As control formulations, peptide was loaded in the same PLGA 75/25 polymer by the conventional double emulsion-solvent evaporation method (W/O/W) and remote loaded in polycondensation poly(lactic-co-glycolic acid) 75/25 (Wako 7515, 14.3kDa). Loading content of 6.7%-8.9% w/w (~ 67%-89% encapsulation efficiency (EE)) was attained for octreotide, and that of 9.5% w/w loading (~ 95% EE) was observed for leuprolide, by the remote loading paradigm. Octreotide and leuprolide were both slowly and continuously released in vitro from the remote-loaded Expansorb® DLG 75-2A MPs for over 56days, which was highly similar to that observed from traditionally-loaded formulations by W/O/W (8.8% loading, 52.8% EE). The faster release kinetics was observed for the faster degrading PLGA 50/50 remote-loaded Expansorb® DLG 50-2A MPs relative to microspheres from the PLGA 75/25 Expansorb® DLG 75-2A. Despite slight differences in degradation kinetics, the release mechanism of octreotide from the Expansorb® microspheres, whether remote loaded or by W/O/W, was identical as determined by release vs. mass loss curves. Octreotide acylation was also minimal (< ~ 10%) for this polymer. Finally, drug-free Expansorb® DLG 75-2A MPs displayed excellent storage stability over 3months. Overall, this work offers support for the use of ring-opening Expansorb® PLGA-based microspheres to remote load peptides to create simple and effective long-acting release depots.

Microfluidic-assisted preparation of PLGA nanoparticles loaded with insulin: a comparison with double emulsion solvent evaporation method

Poly lactic-co-glycolic acid (PLGA) is an ideal polymer for the delivery of small and macromolecule drugs. Conventional preparation methods of PLGA nanoparticles (NPs) result in poor control over NPs properties. In this research, a microfluidic mixer was designed to produce insulin-loaded PLGA NPs with tuned properties. Importantly; aggregation of the NPs through the mixer was diminished due to the coaxial mixing of the precursors. The micromixer allowed for the production of NPs with small size and narrow size distribution compared to the double emulsion solvent evaporation (DESE) method. Furthermore, encapsulation efficiency and loading capacity indicated a significant increase in optimized NPs produced through the microfluidic method in comparison to DESE method. NPs prepared by the microfluidic method were able to achieve a more reduction of trans-epithelial electrical resistance values in the Caco-2 cells compared to those developed by the DESE technique that leads to greater paracellular permeation. Compatibility and interaction between components were evaluated by differential scanning calorimetry and fourier transform infrared analysis. Also, the effect of NPs on cell toxicity was investigated using MTT test. Numerical simulations were conducted to analyze the effect of mixing patterns on the properties of the NPs. It was revealed that by decreasing flow rate ratio, i.e. flow rate of the organic phase to the flow rate of the aqueous phase, mixing of the two streams increases. As an alternative to the DESE method, high flexibility in modulating hydrodynamic conditions of the microfluidic mixer allowed for nanoassembly of NPs with superior insulin encapsulation at smaller particle sizes.

Evaluation of Biodegradable Microparticles for Mucosal Vaccination Against Diphtheria Toxoid: Nasal Efficacy Studies in Guinea Pigs.

In this study, poly-(ɛ-caprolactone) (PCL) and poly-(lactic-co-glycolic acid) (PLGA) microparticles encapsulating diphtheria toxoid (DT) were investigated for their potential as a mucosal vaccine delivery system. Antigen-containing microparticles were prepared using the double emulsion (w/o/w) solvent evaporation method. The average geometric diameter of the particles was found to be between 7 and 24 µm, which is suitable for uptake by the antigen-presenting cells in the nasal mucosa. Although the differences were insignificant, the PLGA polymer-containing formulations exhibited the highest encapsulation efficiency. Microparticle formulations, prepared with both PLGA and PCL polymers, were successfully produced at high production yields. The in vitro release profile was presented as a biexponential process with an initial burst effect due to the release of the protein adsorbed on the microsphere surface, and the subsequent sustained release profile is the result of protein diffusion through the channels or pores formed in the polymer matrix. DT-loaded microparticles, DT solution in phosphate-buffered saline (PBS), and empty microparticles (control) were administered via nasal route and subcutaneously to guinea pigs. The antibody content of each serum sample was determined using an enzyme-linked immunosorbent assay (ELISA). Absorbance values of the ELISA test showed that PLGA- and PCL-bearing microparticles could stimulate an adequate systemic immune response with intranasal vaccination. In addition, PLGA and PCL microparticles resulted in significantly increased IgG titers with intranasal administration as a booster dose following subcutaneous administration. PCL polymer elicited a high immune response compared with PLGA polymer (p <0.05).

Effects of Ultrasound Contrast Agent-Encapsulated Paclitaxel Extract on the Proliferation and Invasion Ability of Hepatocellular Carcinoma Cells

Regarding to the limitations of paclitaxel (PTX) in cancer treatment, PTX was extracted from Taxus chinensis and PTX nano-ultrasound contrast agents (NUCA) were prepared to investigate their impacts on proliferation and invasion of hepatocellular carcinoma (HCC) cells (HCCCs). The PTX extract was obtained through extraction and multi-step purification methods using Taxus chinensis as the source material and poly(lactic-co-glycolic acid)-carboxylic acid (PLGA-COOH) as the experimental material. A modified double emulsion solvent evaporation (DESE) method was employed to prepare paclitaxel-loaded PLGA NUCA (PLGA@PTX). The particle size distribution (PSD) and zeta potential (ZP) of PLGA@PTX were identified using a laser particle size (PS) analyzer, while the drug-loading capacity (DLC) and encapsulation efficiency (EE) of PTX in PLGA@PTX NUCA were evaluated using high-performance liquid chromatography (HPLC). The in vitro release rate (IVRR) of PTX from PLGA@PTX NUCA was also analyzed. HepG2 lines, a human HCC cell line, were grouped into four randomly: a blank control group (Blank), a PTX group, a blank nano-contrast agent group without PTX encapsulation (PLGA), and a PTX-loaded NUCA group (PLGA@PTX). In the Blank group, HepG2 lines were cultured conventionally for 12 hours, while PTX or PLGA@PTX was added to the PTX and PLGA@PTX groups, respectively, to achieve a required concentration (10−7 mol/L) of PTX. An equal amount of PLGA nanoparticles was added to the PLGA group. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Transwell were utilized to judge the impacts of PLGA@PTX nanoparticles on proliferation and invasion of HepG2 lines, respectively. Moreover, flow cytometry (FCT) was utilized to examine the influence of PLGA@PTX nanoparticles on cell cycle (CC) and apoptosis of HepG2 lines. The results revealed that the purity of the PTX extract was as high as 99.04±0.92%. The average PS of PLGA@PTX NUCA was (432.79±4.56) nm, with a surface potential of (−10.79±2.28) mV. Furthermore, the EE and DLC were (89.27±2.63) % and (9.03±0.29) %, respectively. The inhibition rate (IR) to HepG2 lines and cell invasion and the apoptotic rate (AR) in the PLGA@PTX group were much higher to those in the PLGA and PTX groups (P &lt;0.01, P &lt;0.05). The ratio of G1/G0 phase in the CC was greatly lower in the PLGA@PTX group to the PLGA and PTX groups, showing obvious differences with (P &lt;0.05), while that of G2/M phase was higher (P &lt;0.05). These findings indicated that the prepared PLGA@PTX NUCA hindered the proliferation and invasion of HepG2 lines and induced CC arrest at the G2/M phase and apoptosis.

Formulation and Evaluation of Topically Retained Hydrogels Loaded with Timolol Maleate Microspheres for Extended Release in Treating Glaucoma

Conventional aqueous eye drop formulations have a shorter retention period and wash out of the precorneal region more easily. In this study, biodegradable microsphere-loaded hydrogels were developed to extend the time of residence and improve the drug bioavailability. The prepared microspheres were fabricated using PLGA as the biodegradable polymer and PVA as the surfactant. Hydrogels were prepared using Carbopol 940 and Gellan gum as gelling agents. Methods: The microspheres were created through a technique known as double emulsion solvent evaporation method. Evaluation included for its percentage yield, entrapment efficiency, particle size and surface morphology of the prepared microspheres. Timolol Maleate microsphere loaded hydrogel underwent assessments for pH, spreadability, rheological behaviour, sterility, antimicrobial efficacy, in vitro release studies, drug release kinetics and ocular irritation. Results: FTIR analysis confirmed compatibility between the drug and polymer. SEM observations indicated spherical microspheres with sizes ranging from 1 to 12 µm, suitable for ocular application. All formulations exhibited pH values between 4.2 and 5.0, with gelation occurring at 35°C to 38°C. Formulation F3 demonstrated optimal viscosity (1486 – 1850 cps) and good spreadability. Sterility tests were successful, and F3 displayed a drug release of 82.6% after 24 hours. Antimicrobial studies exhibited inhibition zones, and ocular tests on rabbits revealed no irritation. Stability analysis indicated no significant changes in pH or clarity. Conclusion: Based on physiological, rheological, and in vitro evaluations F3 was identified as the most suitable formulation for extended Timolol Maleate release via hydrogel, holding promise for effective glaucoma treatment.

Evaluation of the effect of designed PLGA-arctiin nanoparticles modified with folic acid and chitosan on colon cancer cells.

In this study, we designed nanoparticles (NPs) based on polylactic acid glycolic acid modified with chitosan and folic acid to optimize the anti-cancer, anti-inflammatory, and antioxidant effects of arctiin (ARC), and we measured its effects on cancer cells, including colon cancer. NPs were synthesized using the W1/O/W2 double-emulsion solvent evaporation method. Physicochemical characteristics of synthesized NPs (ARC-PCF-NPs), including average particle size, dispersity index (PDI), zeta potential (ZP), field emission scanning electron microscope figures, and encapsulation efficiency (EE), were evaluated. 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) methods were carried out to determine the antioxidant properties of NPs. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay was performed to investigate cytotoxicity effects on cancer cells and normal fibroblasts. Quantitative polymerase chain reaction was also performed on inflammatory and antioxidant genes. The obtained results indicated that the synthesized NPs have a size of 100nm, a DPI of 0.36, a ZP of 26.30mV, and EE was calculated at about 87.5%. The antioxidant influence of ARC-PCF-NPs was confirmed by inhibiting ABTS and DPPH free radicals and ferrous reduction in the FRAP method. Moreover, the reduction of inflammatory and antioxidant genes confirmed the anti-inflammatory and antioxidant properties of NPs. These results indicate the modification of the surface of NPs in order to increase the bioavailability, stability, and effectiveness of medicinal compounds in therapeutic applications.

Optimizing the formulation variables for encapsulation of linezolid into polycaprolactone inhalable microspheres using double emulsion solvent evaporation

Inhaled antibiotics delivered through dry powder inhalers (DPIs) effectively treat severe bacterial infections by directly targeting the lungs. Our study focused on developing inhalable dry powder microspheres of linezolid (LNZ) using biodegradable polycaprolactone (PCL) polymer. The LNZ-PCL microspheres were fabricated using a double emulsification solvent evaporation method. Optimization of formulation parameters was performed using a factorial design. Evaluation of the microspheres included size, shape, drug loading, entrapment efficiency, aerosolization, and drug release. The morphological analysis confirmed spherical-shaped rough particles within the inhalable size range. The encapsulation efficiency was determined to be 52.84%, indicating successful drug incorporation. Aerosolization efficiency was significantly enhanced when LNZ-PCL microspheres were combined with lactose as a carrier, achieving a fine particle fraction (FPF) value of 70.90%. In-vitro dissolution studies demonstrated sustained drug release for over 24 h under lung pH conditions. Overall, our study highlights the potential of inhalable LNZ-PCL microspheres as a targeted approach for treating pulmonary tuberculosis. Further research and in-vivo studies are needed to validate their effectiveness in life-threatening bacterial infections.

Design of experiments approach for the development of a validated method to determine the exenatide content in poly(lactide-co-glycolide) microspheres

Due to the lack of pharmacopeia guidelines for injectable microspheres based on poly (D, L-lactide-co-glycolide) (PLGA), an internal method validation is a critical prerequisite for quality assurance. One of the essential issues of developing peptide-based drugs loaded PLGA microspheres is the precise determination of the amount of peptide drug entrapped in the microspheres. The aim of this study is the development and optimization of a method for measuring the drug content loading of PLGA microspheres using exenatide as a model peptide drug. Exenatide-loaded PLGA microspheres were prepared by a double emulsion solvent evaporation method. The extraction method to determine exenatide content in microspheres was optimized using Design of Experiments (DoE) approach. After the initial screening of six factors, using Fractional Factorial design (FFD), four of them, including type of organic solvent, buffer/organic solvent ratio (v/v), shaking time and pH, exhibited significant effects on the response, namely the exenatide loading, and a Box-Behnken design (BBD) was subsequently applied to obtain its optimum level. The optimum level for organic solvent volume, buffer/organic solvent ratio, shaking time, and pH were 4 ml, 1, 5.6 hrs, and pH 6, respectively. The exenatide content in microspheres under these conditions was 6.4 ± 0.0 (%w/w), whereas a value of 6.1% was predicted by the derived equation. This excellent agreement between the actual and the predicted value demonstrates that the fitted model can thus be used to determine the exenatide content.

Investigation on modeling and correlating drug release profiles in the accelerated and real-time conditions to formulate leuprolide acetate-loaded biodegradable microspheres

Leuprolide acetate (LA)-loaded microspheres containing different types of biodegradable poly(lactic-co-glycolic acid) (PLGA) were prepared by using the W/O/W double-emulsion solvent evaporation method. These formulations were characterized in terms of particle size, drug loading capacity and drug release kinetics. According to the data on modelling in vitro drug release profiles in accelerated and real-time conditions, the microspheres containing mainly PLGA (L:G = 50:50) or PLGA (L:G = 75:25) exhibited triphasic or biphasic release profiles, respectively. A good correlation was established between real-time at 37 °C and accelerated at 50 °C release data, suggesting that the accelerated release testing method could be useful for a rapid assessment of the in vitro drug release characteristics of the prepared formulations. The particle size, drug loading capacity and drug release characteristics of LA-PLGA microspheres were proved to be dependent upon PLGA types and ratios, and pore-forming agent. With reference to drug release characteristics, our microsphere formulation composed of PLGA 75:25 and ammonium bicarbonate (as a pore-forming agent) was most equivalent to the reference microspheres for 1-month administration.

Evaluation of in vitro immunostimulatory and cytotoxic effects of recombinant survivin protein in combination with doxorubicin and breast cancer antigen-loaded polycaprolactone nanoparticles

In this study, the immunostimulatory and anticancer activities of the doxorubicin (DOX), MCF-7 and MDA-MB-231 breast cancer antigen-loaded polycaprolactone (PCL) nanoparticles (NPs) in combination with survivin recombinant protein (RP) and an alum adjuvant are evaluated in vitro on J774 macrophage, MCF-7 and MDA-MB-231 breast cancer cell lines. A double-emulsion solvent evaporation method was used for encapsulation of DOX and antigens into PCL NPs. The physicochemical characterization of NPs included size, morphology, zeta potential, release profiles and encapsulation efficiencies, analyzed using scanning electron microscopy, a zeta-sizer and UV–vis spectrometry. The cytotoxic and inhibitory effects of NPs were determined using a methyl thiazolyl tetrazolium assay. Immunostimulatory effects of the NPs were detected by Griess reaction and ELISA tests to determine nitric oxide and cytokine levels, respectively. According to the results, DOX and antigen-loaded PCL NPs ranged between 240 nm and 290 nm. Antigen and drug-loaded NPs appear less toxic over macrophage cells in comparison with non-capsulated free agents. In addition, considerable inhibitory effects of antigen and drug-loaded NPs were observed at non-toxic concentrations, such as 25 and 50 μg ml−1, on human mammary cancer cell lines (p⩽ 0.0001). The amount of nitrite released from macrophages that were treated with antigen and DOX-encapsulated PCL NPs, in combination with alum and survivin RP, after 96 h incubation was significantly higher than the control, especially at 50 and 100 μg ml−1, and triggered macrophages to produce high quantities of IL-4 and IL-12 cytokines in contrast to the control. As a result, DOX and antigen-loaded PCL NPs in combination with survivin and alum adjuvant revealed significant immunostimulatory and inhibiting influence on macrophage and breast cancer cells, respectively. The outcomes revealed that antigen and drug-loaded PCL NPs supplemented with survivin RP and an alum adjuvant created an effective platform for the development of nanotechnology-based immunotherapeutic tools to inhibit breast cancer cells. However, these outputs should be supported by further in vivo studies.

Enhanced Cytotoxic Activity of 6-Mercaptopurine-Loaded Solid Lipid Nanoparticles in Hepatic Cancer Treatment.

6-Mercaptopurine (6-MCP) is an antiproliferative purine analog used in acute lymphoblastic leukemia, non-Hodgkin lymphoma, and inflammatory bowel disease (Crohn's disease, ulcerative colitis). Although 6-MCP has the great therapeutic potential for cancer and immunosuppressant-related diseases, 6-MCP is not readily soluble in water, presents a high first-pass effect, short half-life (0.5-1.5 h), and implies a low bioavailability (16%). On the contrary, solid lipid nanoparticles (SLNs) are prepared from solid lipids at room temperature and body temperature. In this study, SLNs were prepared w/o/w double emulsion-solvent evaporation method using Precirol ATO5 as matrix lipid. In the emulsion stabilization, surfactant (Tween 80) and polymeric stabilizer (polyvinyl alcohol [PVA]) were used. Two group formulations using Tween 80 and PVA were compared in terms of particle size, polydispersity index, zeta potential encapsulation efficiency%, and process yield%. Differential calorimetric analysis and release properties were examined for optimum formulation, and release kinetics were calculated. According to studies, sustained release was obtained with SLNs by the Korsmayer-Peppas kinetic model. The in vitro cytotoxicity studies were performed on the hepatocarcinoma (HEP3G) cell line. According to the results, successful SLN formulations were produced, and PVA was found best stabilizer. Optimum formulation exhibited significantly higher cytotoxic effects on HEP3G than on pure 6-MCP. These results demonstrated that solid lipid nanodrug delivery systems have great potential for formulation of 6-MCP.