Emulsion Solvent Evaporation Technique Research Articles

Nanoparticle formulation of the fusion protein virus like particles of respiratory syncytial virus stimulates enhanced in vitro antigen presentation and autophagy

Respiratory Syncytial Virus (RSV) is one of the leading causes of bronchiolitis and pneumonia in childrenunder one year globally. As a result, RSV poses a severe burden on healthcare services. Thus, a vaccine for RSV is a global need. Utilizing polymeric nanoparticles as a delivery system for vaccine antigen holds a lot of promise. In this study, the virus like particles of RSV fusion protein (F-VLP) was encapsulated in poly (D, L-lactide-co-glycolide) (PLGA) nanoparticles (NP). The F-VLP NP was formulated using a double emulsion solvent evaporation technique. The optimized NPs had a particle size of 525 ± 10.5 nm and an antigen encapsulation efficiency of 73% ± 10.5. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis showed that the F-VLP was stable post formulation. The F-VLP NP showed a sustained release of the F-VLP antigen for up to a week. In vitro study revealed that the F-VLP NP were non-cytotoxic, and the cellular uptake of the NPs by dendritic cells was observed within 3 h. The F-VLP NP with adjuvant monophosphoryl lipid A (MPL) NP and without MPL NP showed enhanced expression of antigen presentation molecule major histocompatibility complex (MHC)-I and autophagosomes in dendritic cells. In summary, the sustained release of the antigen from the F-VLP NP and the particulate nature of the vaccine resulted in enhanced antigen presentation and induction of autophagy in antigen-presenting cells (APCs).

Novel Utilization of Therapeutic Coatings Based on Infiltrated Encapsulated Rose Bengal Microspheres in Porous Titanium for Implant Applications.

Despite the increasing progress achieved in the last 20 years in both the fabrication of porous dental implants and the development of new biopolymers for targeting drug therapy, there are important issues such as bone resorption, poor osseointegration, and bacterial infections that remain as critical challenges to avoid clinical failure problems. In this work, we present a novel microtechnology based on polycaprolactone microspheres that can adhere to porous titanium implant models obtained by the spacer holder technique to allow a custom biomechanical and biofunctional balance. For this purpose, a double emulsion solvent evaporation technique was successfully employed for the fabrication of the microparticles properly loaded with the antibacterial therapeutic agent, rose bengal. The resulting microspheres were infiltrated into porous titanium substrate and sintered at 60 °C for 1 h, obtaining a convenient prophylactic network. In fact, the sintered polymeric microparticles were demonstrated to be key to controlling the drug dissolution rate and favoring the early healing process as consequence of a better wettability of the porous titanium substrate to promote calcium phosphate nucleation. Thus, this joint technology proposes a suitable prophylactic tool to prevent both early-stage infection and late-stage osseointegration problems.

Study of sonication parameters on PLA nanoparticles preparation by simple emulsion-evaporation solvent technique

The design of polymeric nanoparticles (PNPs) for delivery and controlled release of drugs has been increasing in the last decades, where polymeric materials such as biocompatible and degradable polyesters have advantages. However, it is necessary to control and modulate the size of the nanoparticles (NPs) to prevent uptake and clearance by the reticuloendothelial system and achieve selective delivery on a pharmaceutical target. In this mediation, the modulation of the particle size (PS) and polydispersity index (PDI) is one of the most sought parameters. In this work, a study of external parameters such as power, time, and cycles in sonication for the preparation of polymeric nanoparticles (PNPs) with polylactic acid (PLA) by the simple emulsion-solvent evaporation (SE-SE) technique using ultrasound was carried out. A Box-Behnken method was used to improve and optimize the conditions for obtaining the nanoformulation, which allowed obtaining response surfaces to figure out the effect of the parameters on PS, PDI, and ζ-Potential. This study showed that the main influential parameter on particle size and PDI is power, followed by the time of sonication, and finally, the number of sonication cycles. The statistical model allowed the prediction and modulation of the variables to obtain particle diameters between 110 and 240 nm, PDI 0.09–0.32, and ζ-Potential remained relatively constant in each experiment with an average value of −21.0 mV. The adequate conditions for preparing PNPs are using 20% of the power of ultrasound employed, 20 s of sonication, and two cycles with a pause of 10 s between each pulse when a PLA of 136 kDa is used. The particle size and PDI of the optimized PLA NPs were 144.5 ± 0.5 nm and 0.1347 ± 0.0064, respectively. Additionally, this model can develop desired PS nanoformulations with excellent size homogeneity.

Dual Vinorelbine bitartrate and Resveratrol loaded polymeric aqueous core nanocapsules for synergistic efficacy in breast cancer

Aim The current study focussed on the development and evaluation of aqueous core nanocapsules (ACNs) as an effective carrier to deliver an optimal synergistic combination of a highly water-soluble Vinorelbine bitartrate (VRL) and a poorly water-soluble Resveratrol (RES) for treatment of breast cancer. Methods Various molar ratios of VRL to RES were screened against MCF-7 cell lines to determine the synergistic effects using the Chou-Talalay method. The synergistic ratio of therapeutic agents was then incorporated into aqueous core nanocapsules utilising a double emulsion solvent evaporation technique to yield dual drug-loaded nanocapsules (dd-ACNs). The dd-ACNs were optimised using Box-Behnken design and characterised for physicochemical parameters such as particle size, zeta potential, polydispersity index, total drug content and encapsulation efficiency, surface morphology, drug excipient compatibility by FTIR and DSC, release kinetics, toxicity studies and anticancer efficacy (in-vitro and in-vivo). Results Results demonstrated that the combination exhibited maximum synergy when higher doses of VRL were combined with smaller doses of RES (1:1, 5:1, and 10:1). The dual drug-loaded ACNs were found to be stable and depicted a core-shell structure, narrow size range (150.2 ± 3.2 nm) with enhanced encapsulation (80% for VRL and 99% for RES). Moreover, the dd-ACNs were 5 times more efficacious in-vitro than a combination of free drugs, while reducing systemic toxicity. Also, pre-clinical evaluation of dd-ACNs also depicted a drastic reduction of tumour volume as compared tp pristine VRL and a physical combination of drugs. Conclusion The developed dd-ACNs can be applied as a potential carrier for delivery of a combination of chemotherapeutics at a synergistic ratio at the tumour site.

Bromelain Loaded Lipid-Polymer Hybrid Nanoparticles for Oral Delivery: Formulation and Characterization.

Bromelain (Br), a mixture of proteolytic enzymes from pineapple (Ananas comosus), has various therapeutic potentials; however, its low bioavailability has limited the clinical applications specifically in oral delivery as the most common convenient used route of administration. In the present study, a lipopolymeric nanoparticle (NP) containing Br was developed to enhance its stability and oral delivery efficiency. Firstly, Br was loaded into poly (D, L-lactide-co-glycolide acid) (PLGA) and PLGA-phosphatidylcholine (PLGA-PC) NPs using double emulsion solvent evaporation technique. Then, Br integrity and activity were investigated using SDS-PAGE and gelatin test. The stability and release profile of Br from synthetized NPs were evaluated at different pH values of the digestive system. Furthermore, cytotoxicity, cellular uptake, and the amount of Br passage from Caco-2 cells were explored. The results showed PLGA-PC-Br NPs had higher encapsulation efficiency (83%) compared to PLGA-Br NPs (50%). In addition, this NP showed more Br released in neutral (20.36%) and acidic (34%) environments compared to PLGA-Br NPs after 5 days. The delay in the release of Br from PLGA-PC-Br NPs versus the faster release of Br from PLGA-Br formulation could assure that an appropriate concentration of Br has reached the intestine. Intestinal absorption study demonstrated that lipid polymer NPs were able to pass through Caco-2 cells about 1.5 times more (98.4%) than polymeric NPs (70%). In conclusion, PLGA-PC NPs would be considered as a promising lipid-polymer nanocarrier for effective intestinal absorption of Br.

Developed meloxicam loaded microparticles for colon targeted delivery: Statistical optimization, physicochemical characterization, and in-vivo toxicity study.

The study aimed to fabricate and evaluate Meloxicam (MLX) loaded Hydroxypropyl Methylcellulose (HPMC) microparticles for colon targeting because MLX is a potent analgesic used in the treatment of pain and inflammation associated with colorectal cancer (CRC). Nevertheless, its efficiency is limited by poor solubility and gastrointestinal tracts (GIT) associated side effects. Seventeen formulations of MLX loaded HPMC microparticles were fabricated by the oil-in-oil (O/O)/ emulsion solvent evaporation (ESE) technique. A 3-factor, 3-level Box Behnken (BBD) statistical design was used to estimate the combined effects of the independent variables on the dependent variables (responses), such as the percent yield (R1), the entrapment efficiency (EE) (R2), mean particle size (R3) and in vitro percentage of cumulative drug release (R4). For physicochemical characterization FTIR, XRD, DSC, and SEM analyses were performed. Biocompatibility and non-toxicity were confirmed by in-vivo acute oral toxicity determination. The percentage yield and EE were 65.75-90.71%, and 70.62-88.37%, respectively. However, the mean particle size was 62.89-284.55 μm, and the in vitro cumulative drug release percentage was 74.25-92.64% for 24 hours. FTIR analysis showed that the composition of the particles was completely compatible, while XRD analysis confirmed the crystalline nature of the pure drug and its transition into an amorphous state after formulation. DSC analysis revealed the thermal stability of the formulations. The SEM analysis showed dense spherical particles. The toxicity study in albino rabbits showed no toxicity and was found biocompatible. The histopathological evaluation showed no signs of altered patterns. Results of this study highlighted a standard colonic drug delivery system with the ability to improve patient adherence and reduce GIT drug-associated side effects in CRC treatment.

Effect of the Emulsion Solvent Evaporation Technique Cosolvent Choice on the Loading Efficiency and Release Profile of Anti-CD47 from PLGA Nanospheres

IntroductionSide effects associated with using antibodies as therapeutics can limit systemic administration at the high concentrations often needed for therapeutic impact. Thus, therapeutic antibodies are usually considered for targeted delivery. Antibody encapsulation in polymeric nanoparticles via the emulsion-based nanofabrication methods typically yields low loading efficiencies. Therefore, the fabrication techniques need to be modified to maximize the loading efficiency of antibodies. In this work, we utilized various cosolvents with the emulsion solvent evaporation technique to improve the loading efficiency of anti-CD47, a therapeutic antibody used to block CD47 activity in atherosclerotic plaques and cancer lesions. Methods and ResultsThe double emulsion solvent evaporation technique was used to fabricate anti-CD47-loaded polymeric nanoparticles. The primary oil phase solvent, chloroform, was doped with different cosolvents, including ethyl acetate, acetonitrile, ethanol, and methanol, to investigate the impact of cosolvents on the loading efficiency of anti-CD47. The release profile and loading efficiency were quantified by measuring the fluorescence signal of the released antibody. The activity of the antibody released from particles fabricated in the presence of the cosolvent was confirmed by quantifying its adherence to red blood cells. Ethyl acetate was the optimum cosolvent, improving the loading efficiency of anti-CD47 in poly(lactic-co-glycolic acid), PLGA, nanoparticles to 90% or higher, and the antibody was found to retain its activity after being released from nanoparticles. ConclusionOur results demonstrate that a minimum amount of a cosolvent with minimal hydrophilicity can stabilize the antibody in the oil phase; thus, improving the antibody's loading efficiency significantly.

Design of polymeric nanoparticles for oral delivery of capreomycin peptide using double emulsion technique: Impact of stress conditions

Peptides are short polymers of amino acids that are unstable at drastic conditions including highly acidic or highly alkaline media, high temperature and high shear forces. Polymeric nanoparticles as carrier for peptides are the most desirable formulation in pharmaceutical field than other colloidal systems because of their stability in biological environment. Two different biodegradable polymers were chosen to formulate nanoparticles as carriers for capreomycin sulfate (CMS) peptide. Chitosan was selected as a water soluble polymer, while, poly(lactic-co-glycolic) acid (PLGA) polymer is soluble in organic solvents. Double emulsion solvent evaporation technique was used in the formulation of the nanoparticles. This method required applying of thermal, mechanical and chemical stresses that could have impact on peptide degradation that should be considered in the design of nanoparticles. Many formulation factors for polymeric nanoparticles optimization were tested including: probe sonication intensity and time, homogenization speed, pH of dispersion media, drug:polymer ratios, type and concentration of crosslinking agents and concentration of the stabilizer. Controlling these factors with monitoring of peptide degradation allowed to optimize polymeric nanoparticles having the smallest possible particle sizes (343.7–1656.5 nm) with the highest entrapment efficiencies (17.30–62.30%). The produced polymeric nanoparticles were tested for in vitro drug release in phosphate buffer pH 6.8. Different CMS release profiles were observed (15.52–72.44%) where PLGA NPs showed significant slower release compared with that of chitosan NPs.

Nanocoating and biological evaluation of clindamycin- and rifampicin-loaded nanospheres impregnated Silicone tube for antibacterial application

Two types of nanospheres, namely clindamycin-loaded nanospheres (CN) and rifampicin-loaded nanospheres (RN) were successfully prepared using emulsion solvent evaporation technique. Poly(ε-caprolactone-random-D,L-lactide)-block-poly(ethylene glycol)-block-poly(ε-caprolactone-random-D,L-lactide) (PLEC) was used for preparing nanospheres. CN and RN were coated on an antibiotic-impregnated silicone tube surface by spray coating technique. The formulations of antibiotic-loaded nanospheres (CN and RN) and the amount of spray coating cycles were optimized. Drug loading content, encapsulation efficiency, zeta potential, and size of nanospheres were characterized. The optimal ratios of PLEC to clindamycin; and PLEC to rifampicin were both at 2:1. Drug loading contents of CN and RN were 2.62 ± 0.04% and 7.02 ± 0.02%, respectively. The optimum coating of 90 cycles were provided drug loading contents of 0.0637 ± 0.033 wt.% and 0.0613 ± 0.018 wt.% for rifampicin and clindamycin, respectively. The coating of silicone tube was able to prolong the release of both antibiotics for at least 30 days. Antibacterial activity test was performed using MRSA (ATCC 43300) and S. Epidermidis (ATCC 12228). Moreover, the cytotoxicity of antibiotic-loaded nanospheres coated on silicone tubes was evaluated. The coated silicone tube showed antibacterial activity for at least 28 days and was biocompatible with L929 cells.

Gentiopicroside PLGA Nanospheres: Fabrication, in vitro Characterization, Antimicrobial Action, and in vivo Effect for Enhancing Wound Healing in Diabetic Rats

PurposeGentiopicroside (GPS), an adequate bioactive candidate, has a promising approach for enhancing wound healing due to its antioxidant and antimicrobial properties. Its poor aqueous solubility negatively affects oral absorption accompanied by low bioavailability due to intestinal/hepatic first-pass metabolism. Our aim in this study is to fabricate GPS into appropriate nanocarriers (PLGA nanospheres, NSs) to enhance its solubility and hence its oral absorption would be improved.MethodsNormal and ODS silica gel together with Sephadex LH20 column used for isolation of GPS from Gentiana lutea roots. Crude GPS would be further processed for nanospheres fabrication using a single o/w emulsion solvent evaporation technique followed by in vitro optimization study to examine the effect of two formulation variables: polymer (PLGA) and stabilizer (PVA) concentrations on the physical characterizations of prepared NSs. Possible GPS-PLGA chemical and physical interactions have been analyzed using Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The optimum GPS-PLGA NSs have been chosen for antimicrobial study to investigate its inhibitory action on Staphylococcus aureus compared with unloaded GPS NSs. Also, a well-designed in vivo study on streptozotocin-induced diabetic rats has been performed to examine the wound healing effect of GPS-PLGA NSs followed by histological examination of wound incisions at different day intervals throughout the study.ResultsThe optimum GPS PLGA NSs (F5) with well-controlled particle size (250.10±07.86 nm), relative high entrapment efficiency (83.35±5.71), and the highest % cumulative release (85.79±8.74) have increased the antimicrobial activity as it exhibited a higher inhibitory effect on bacterial growth than free GPS. F5 showed a greater enhancing impact on wound healing and a significant stimulating effect on the synthesis of collagen fibers compared with free GPS.ConclusionThese findings demonstrate that loading GPS into PLGA NSs is considered a promising strategy ensuring optimum GPS delivery for potential management of wounds.

Optimisation and evaluation of Gymnema sylvestre extract loaded polymeric nanoparticles for enhancement of in vivo efficacy and reduction of toxicity

Aim This work studies the development and evaluation of Gymnema sylvestre (GYM) extract loaded sustained release polymeric nanoparticles (PNPs) for enhanced bioavailability and reduced nephrotoxicity. The current therapy is associated with the drawbacks of addiction and repeated administration. Method The sustained release PNPs were developed and evaluated for toxicity. PNPs of GYM were prepared by double emulsion solvent evaporation technique utilising Taguchi model and evaluated for physicochemical properties (particle size, zeta potential, entrapment efficiency), in vitro drug release, compatibility, and stability. Further, the bioavailability and in vivo nephrotoxicity studies in diabetic rat model were also carried out. Result The developed optimised nanoparticles were 205.7 ± 1.20 nm in size, −40.68 mV zeta potential, compatible, and stable in nature with improved entrapment efficiency (67.1 ± 0.2%) and sustained release. Moreover, nanoparticles were found to lower the blood glucose level in single as well as multiple doses. Results of in vivo study indicated that GYM-NPs increased the phosphorylase activity and thus enhanced insulin secretion. Furthermore, the nanoparticles were free from toxicity, which was confirmed by the estimation of kidney biomarker. Conclusion The nanoparticles increased the bioavailability of GYM extract and have a great potential for the treatment of diabetes in reduced dose, and so these can be potential candidates for treating diabetes.

Preparation and Evaluation of Eprosartan Mesylate loaded PLGA Nanostructures

In modern medication, drug-loaded novel polymeric nanoparticles have potential advantages over conventional dosage forms. The present study focused on the formulation development and evaluation of newly introduced angiotensin receptor blocker (ARB) eprosartan mesylate loaded biodegradable acid terminated poly(lactide-co-glycolide) (50:50) nanoparticle using double emulsion solvent evaporation technique. This methodology was found to improve the therapeutic efficacy as Eprosartan Mesylate belongs to BCS class-II and water-insoluble antihypertensive drug with 13% bioavailability. In the earlier stage, screening was performed to find out the suitable combination of excipients (Polyvinyl alcohol, Dichloromethane and Ethanol) to formulate the nanoparticles. In this present study, the physical and chemical properties of polymer and drug were determined before and after the formulation of nanoparticles using experimental techniques, such as Differential Light Scattering (DLS), zeta potential, X-ray Deffractometry (XRD), Fourier-Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and Liquid Chromatography-Mass Spectrometry (LC-MS/MS) analysis. The eprosartan mesylate loaded PLGA nanoparticles showed fairly monodispersive, as determined from DLS (average particle diameter 136 nm, Poly Dispesity Index = 0.3). The zeta potential was found to be -10.8mV. This formulation showed a prolonged improved drug release (82.03%) for 360 hours in phosphate buffer (pH7.4) as compared to the conventional marketed dosage form. In-vitro release kinetics data of NPs (R2=0.8979) and diffusion exponent values (n=0.3328) suggested that optimized followed the Korsmeyer-Peppas model with Fickian mechanism.

Mechanistic evaluation of lymphatic targeting efficiency of Atazanavir sulfate loaded lipid nanocarriers: In-vitro and in-vivo studies

In the present study, Atazanavir sulfate-loaded solid lipid nanoparticles (ATZ-SLNs) were developed and characterized for oral bioavailability enhancement and lymphatic absorption. ATZ-SLNs were formulated by emulsion-solvent evaporation technique using hydrogenated castor oil and sodium oleate. The optimized formulation had a mean particle size of 190.1 ± 2.45 nm, the zeta potential of −42.63 ± 2.46 mV and entrapment efficiency of 94.26 ± 2.12%. Transmission electron microscopy and Field emission-scanning electron microscopy morphology indicated discrete and round structures without aggregation. In-vitro drug release study showed controlled drug release of 80.36% in 12 h in simulated intestinal fluid. Cell-line study in Caco-2 cells showed increased permeability upon SLN formulation and mode of cellular uptake of SLN as clathrin and caveoli mediated endocytosis. In-vivo pharmacokinetic study in rats indicated increased oral bioavailability using ATZ-SLNs by 200% compared to suspension formulation. A lymphatic transport study revealed that SLNs were transported via lymphatic vessels. In organ biodistribution study, peyer's patch region showed a 4.5 fold higher uptake of ATZ through ATZ-SLNs formulation than non-peyer's patch region and high accumulation in spleen and brain. This delivery approach could maximize the drug concentrations to the lymphatic system leading to effective therapy for HIV.

Poly(Lactide-co-Glycolide) Nanoparticle-Mediated Vaccine Delivery of Encapsulated Surface Antigen Protein of Hepatitis B Virus Elicits Effective Immune Response.

Hepatitis B viral infection is one of the most important infectious diseases of the liver worldwide. Chronic infection with HBV often leads to cirrhosis and hepatocellular carcinoma. The currently licensed hepatitis B vaccine consists of recombinant hepatitis B surface antigen adsorbed into aluminum adjuvant and administered in three doses over the course of 6 months. However, this vaccine requires invasive administration and requires multiple booster doses. To avoid these limitations, nanoparticle (NP)-based vaccines lent itself as efficient adjuvants and delivery systems for the development of new generation vaccines. The biodegradable synthetic polymeric NPs poly(lactide-co-glycolide) (PLGA) was used in this study to formulate PLGA NPs encapsulated with hepatitis B surface protein to evaluate immune response in human peripheral blood lymphocytes in vitro. Formulation of HBP (HBV surface protein)-encapsulated PLGA (HB-nanovaccine [HB-NV]) was conducted by using double emulsion solvent evaporation technique (water-oil-water), which resulted in 94% encapsulation efficiency and 24% protein loading capacity. The resulted HB-NV had typical characteristics of spherical shape at an average size of 71.08 nm with higher densities and high stability dispersion of negatively charged NPs as assessed by atomic force microscopy, scanning electron microscopy, ultraviolet absorption spectrophotometry, zeta potential, and Fourier-transform infrared. The immune response to HB-NV was measured in vitro in lymphocytes, showed significant increase in levels of IL-2 and IFN-γ, as well as in CD4+ and CD8+ T cell counts, with a dose-dependent effect, examined by enzyme-linked immunosorbent assay and flow cytometry, respectively.

Formulation of Enalapril-Loaded Microspheres Using Emulsion Solvent Evaporation Technique for Bitter Taste Masking

The aim of the present study was to formulate polymer microspheres using the emulsion solvent evaporation technique as an approach to mask the bitter taste of enalapril maleate. Five models were prepared with two water-insoluble polymers. Talc was used to stabilize the particle structure. Production yields ranged from 38 % to 53 %; drug loading varied between 17 % and 40 %; the mean particle size ranged from 140 μm to 339 μm. No interaction between enalapril and the polymers was estimated. A drug release study in artificial saliva indicated a negligible amount of enalapril dissolved in the test medium which demonstrated successful taste masking.

Effect of Polymers in the Design and Characterization of Sustained Release Aceclofenac Microspheres

Purpose:Theaim of present work was to design and characterize sustained release Aceclofenac, model drug, microspheres by emulsion solvent evaporation technique.Methods:Aceclofenac microspheres were prepared by emulsion solvent evaporation process by using Ethyl cellulose and Hydroxy propyl methyl cellulose as polymers. The microspheres were evaluated by drug release study, drug content, drug loading and encapsulation efficiency, and determination of percentage yield.Results:The present study shows that as the polymer concentration increases the percentage encapsulation efficiency, and drug content in the microsphere formulation also increases. The microspheres of all the formulated batches were spherical, discrete and free flowing. Increasing the polymer concentration in microsphere formulation decreases the rate of drug release dramatically.Conclusions:It might be concluded that drug loaded microspheres appear to be a suitable delivery system for a model drug, Aceclofenac, and may help to reduce dose of drug andfrequency of administration. Sustained release of Aceclofenac microspheres could be formulated by using ethyl cellulose and HPMC as a release retardant by emulsion solvent evaporation technique.©2022iGlobal Research and PublishingFoundation. All rights reserved

A Study on the Effects of Surfactant Concentration and Particle Size on Ethylcellulose Microspheres Containing Indinavir Sulphate

Microspheres containing indinavir sulfate were prepared by the emulsion solvent evaporation technique using surfactant sorbitan monooleate 80. The evaluation reports for Fourier-transform infrared spectroscopy and X-ray diffraction spectroscopy were taken to see whether the surfactant altered the physicochemical features of the produced microspheres. Scanning electron microscopy was used to observe the surface topography of the microspheres. When sorbitan monooleate 80 was employed at dissimilar concentrations, the sorbitan monooleate 80 microspheres had higher concentrations that resulted in smaller particle size as compared to the lower concentrations of sorbitan monooleate 80 microspheres, therefore, the faster release rate was observed by utilizing a higher concentration of sorbitan monooleate 80. The microspheres entrapped 71 % to 96 % of the drug and released it for up to 7 h. X-ray diffraction revealed a decrease in the crystallinity of the drug. Scanning electron microscopy analysis revealed the spherical and after dissolution detected porous structure of microspheres. The excellent fit release kinetics is accomplished with the zero-order, Higuchi plot followed by first-order, Hixson-Crowell and Korsmeyer-Peppas equations. As a result, the drug indinavir sulfate release rate was influenced by surfactant concentrations, drug-polymer ratio, particle size and the diffusion release mechanism.

Long-acting microspheres of Human Chorionic Gonadotropin hormone: In-vitro and in-vivo evaluation

Human Chorionic Gonadotropin (hCG) hormone is used to cause ovulation, treat infertility in women, and increase sperm count in men. Conventional hCG solution formulations require multiple administration of hCG per week and cause patient noncompliance. The long-acting PLGA depot microspheres (MS) approach with hCG can improve patient compliance, increase the efficacy of hCG with a lower total dose and improve quality of life. Therefore, hCG was encapsulated by a modified double emulsion solvent evaporation technique within PLGA MS by high-speed homogenizer and industrially scalable in-line homogenizer, respectively. MS was characterized for particle size, encapsulation efficiency (EE), surface morphology, and in-vitro release. The spherical, dense, non-porous microspheres were obtained with a size of 58.88 ± 0.18 µm. Microspheres showed high EE (77.4% ± 5.9%) with low initial burst release (12.82% ± 2.07%). Circular Dichroism and SDS-PAGE analysis indicated good stability and structural integrity of hCG in the microspheres. Its bioactivity was proven further by a bioassay study in immature Wistar rats. Pharmacokinetic analysis showed that the hCG PLGA MS maintained serum hCG concentration up to 13 days compared to multiple injections of a marketed conventional parenteral injectable formulation of hCG. Thus, it can be ascertained that the hCG PLGA MS may have great potential for clinical use in long-term therapy.

Sustained Release of Risedronate from PLGA Microparticles Embedded in Alginate Hydrogel for Treatment of Bony Lesions

Background:Inflammatory bone resorption in periodontitis can lead to tooth loss. Systemic administration of bisphosphonates such as risedronate for preventing bone resorption can cause adverse effects. ALG and PLGA microparticles have been studied as drug delivery systems for sustained release of drugs. Therefore, the release pattern of risedronate from PLGA microparticles embedded with ALG was studied as a drug delivery system for sustained release of the drug, which can be used in local administrations. Methods:Risedronate-containing PLGA microparticles were fabricated using double emulsion solvent evaporation technique. Ionic cross-linking method was used to fabricate risedronate-loaded ALG. Risedronate-containing PLGA microparticles were then coated with ALG. The calibration curve of risedronate was traced to measure EE and study the release pattern. SEM imaging was carried out, and cell toxicity was examined using MTT assay. Statistical analysis of data was carried out using SPSS ver. 20 software, via one-way ANOVA and Tukey’s tests. Results:SEM imaging showed open porosities on ALGs. The mean EE of PLGA microparticles for risedronate was 57.14 ± 3.70%. Risedronate released completely after 72 h from ALG, and the cumulative release was significantly higher (p = 0.000) compared to PLGA microspheres coated with ALG, which demonstrated sustained released of risedronate until day 28. Risedronate-loaded ALG showed a significant decrease in gingival fibroblasts cell viability (p < 0.05). Conclusion: Alginate-coated PLGA microspheres could release risedronate in a sustained and controlled way and also did not show cell toxicity. Therefore, they seem to be an appropriate system for risedronate delivery in local applications.

Comparison Study Between Encapsulation of Acalypha indica Linn Extracts with Chitosan-PCL and Chitosan-OA

Drug delivery is one of the major applications in the biodegradable polymer science. Chitosan is a non-toxic and naturally biodegradable polymer. It is soluble in acidic aqueous media and insoluble in higher pH media. Chitosan has been modified to improve its properties such as stability and the modified derivatives have been widely used in many applications especially for drug delivery. There are several kinds of chitosan modification. This study investigated the modification of chitosan with polyester-types of polymer and the fatty acidbased polymer. The aim of this study is to compare the formation encapsulation of chitosan-oleic acid conjugate (Ch-OA) and chitosan- polycaprolactone(PCL) copolymer for the encapsulation of Acalypha indica active compounds for drug delivery by using emulsion-solvent evaporation technique. The crude extracts have been extracted and the phytochemicals inside the crude extracts are less stable in nature. These active compounds need to be encapsulated to stabilize them and delivered well into the body system. As for conclusion, chitosan:PCL is able to form better encapsulation using this method.