A novel vehicle for local protein delivery to the inner ear: injectable and biodegradable thermosensitive hydrogel loaded with PLGA nanoparticles

Delivery of biomacromolecular drugs into the inner ear is challenging, mainly because of their inherent instability as well as physiological and anatomical barriers. Therefore, protein-friendly, hydrogel-based delivery systems following local administration are being developed for inner ear therapy. Herein, biodegradable poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) containing interferon α-2?b (IFN α-2?b) were loaded in chitosan/glycerophosphate (CS/GP)-based thermosensitive hydrogel for IFN delivery by intratympanic injection. The injectable hydrogel possessed a physiological pH and formed semi-solid gel at 37?°C, with good swelling and deswelling properties. The CS/GP hydrogel could slowly degrade as visualized by scanning electron microscopy (SEM). The presence of NPs in CS/GP gel largely influenced in vitro drug release. In the guinea pig cochlea, a 1.5- to 3-fold increase in the drug exposure time of NPs-CS/GP was found than those of the solution, NPs and IFN-loaded hydrogel. Most importantly, a prolonged residence time was attained without obvious histological changes in the inner ear. This biodegradable, injectable, and thermosensitive NPs-CS/GP system may allow longer delivery of protein drugs to the inner ear, thus may be a potential novel vehicle for inner ear therapy.     

Use of a Novel Modified TSI for the Evaluation of Controlled-Release Aerosol Formulations. I

When considering the development of potential controlled-release pulmonary drug delivery systems, there is at present no standard method available for the assessment of in vitro drug release profiles necessary to understand how the drug might release following deposition in the lungs. For this purpose, the twin-stage impinger (TSI), apparatus A of the BP, has been redesigned and tested. This modified TSI was found capable of discriminating between drug release rates from conventional and different dry powder formulations consisting of model controlled-release excipients, providing information related to (a) drug diffusion properties of controlled-release dry powder blends with different excipient components and (b) the effect of varying drug concentration within a given formulation.     

Formulation development of physiological environment responsive periodontal drug delivery system for local delviery of metronidazole benzoate

The objective of the present investigation was to develop and evaluate physiological environment responsive periodontal drug delivery system (PERPDDS) for local delivery of metronidazole benzoate. Poly-?-caprolactone an in situ precipitating polymer was used in combination with, carbopol 934P, a pH simulative polymer to develop PERPDDS. The prepared PERPDDS was evaluated for various parameters such as in vitro gelling capacity, viscosity, rheology, compatibility study, and in vitro diffusion study. A 3² full factorial design was used to investigate the influence of formulation variables. Drug release data from all formulations were fitted to different kinetic models and the korsemeyer-peppas model was found the best fit model. The value of diffusional exponent (n) was in between 0.3283 and 0.3979 indicating purely fickian diffusion release mechanism. Increasing the concentration of each polymeric component increases viscosity, and time for 50% and 90% drug release was observed and graphically represented by the surface response and contour plots.     

Phytantriol based liquid crystal provide sustained release of anticancer drug as a novel embolic agent

Phytantriol has received increasing amount of attention in drug delivery system, however, the ability of the phytantriol based liquid crystal as a novel embolic agent to provide a sustained release delivery system is yet to be comprehensively demonstrated. The purpose of this study was to prepare a phytantriol-based cubic phase precursor solution loaded with anticancer drug hydroxycamptothecine (HCPT) and evaluate its embolization properties, in vitro drug release and cytotoxicity. Phase behavior of the phytantriol–solvent–water system was investigated by visual inspection and polarized light microscopy, and no phase transition was observed in the presence of HCPT within the studied dose range. Water uptake by the phytantriol matrices was determined gravimetrically, suggesting that the swelling complied with the second order kinetics. In vitro evaluation of embolic efficacy indicated that the isotropic solution displayed a satisfactory embolization effect. In vitro drug release results showed a sustained-release up to 30 days and the release behavior was affected by the initial composition and drug loading. Moreover, the in vitro cytotoxicity and anticancer activity were evaluated by MTT assay. No appreciable mortality was observed for NIH 3T3 cells after 48?h exposure to blank formulations, and the anticancer activity of HCPT-loaded formulations to HepG2 and SMMC7721 cells was strongly dependent on the drug loading and treatment time. Taken together, these results indicate that phytantriol-based cubic phase embolic gelling solution is a promising potential carrier for HCPT delivery to achieve a sustained drug release by vascular embolization, and this technology may be potential for clinical applications.     

In situ gelling formulation based on methylcellulose/pectin system for oral-sustained drug delivery to dysphagic patients

Background: Oral-sustained release gel formulations with suitable rheological properties have been proposed as a means of improving the compliance of dysphagic and geriatric patients who have difficulties with handling and swallowing oral dosage forms. Aim: We have modified the rheological and release properties of thermally reversible methylcellulose solutions by admixture with pectin, the gelation of which is ion-responsive, with the aim of formulating an in situ gelling vehicle suitable for oral-sustained drug delivery. Method: Gels formed by solutions containing methylcellulose (1.0–2.0%) and pectin (0.5–2.0%) were assessed for suitable gel strength, and in vitro and in vivo release of paracetamol. Results: Addition of 1.5% pectin to a 2.0% methylcellulose formulation containing 20% d-sorbitol and calcium ions in complexed form increased the gel strength and provided a formulation with a suitable viscosity for ease of swallowing by dysphagic patients. Gels formed in situ after oral administration of this formulation retained their integrity in the rat stomach for sufficient time for sustained release to be achieved. In vitro release of paracetamol from methylcellulose, pectin, and methylcellulose/pectin gels was diffusion-controlled. Plasma levels of paracetamol after oral administration to rats (gastric pH 2.6 and 5.5) of a solution including 2.0% methylcellulose/1.5% pectin showed improved sustained release compared with that from both 2.0% methylcellulose and 1.5% pectin solutions. Conclusions: The addition of suitable concentrations of pectin to methylcellulose solutions produces in situ gelling formulations with suitable viscosity for administration to dysphagic patients and improved sustained release characteristics.     

Proniosomal gel-mediated transdermal delivery of bromocriptine: in vitro and ex vivo evaluation

Vesicular systems endow large opportunities for the transdermal delivery of therapeutics. The present study was designed to investigate the potential of a novel class of vesicular system ‘proniosome’ as a carrier for transdermal delivery of bromocriptine (BCT). Proniosome formulations were prepared by the coacervation-phase separation method and the influence of factors like surfactant type and its amount, lipid concentration, cholesterol amount and drug content were studied. Span 60 was the most appropriate surfactant, and yielded vesicle size and percentage encapsulation efficiency of 1.3 µm and 98.9%, respectively. The developed system was characterised w.r.t. morphology, transition temperature, drug release, skin permeation and skin irritancy. Proniosomes exhibited a sustained release pattern of BCT in vitro. Skin permeation study revealed high penetration of proniosomes with sustained release of BCT through rat skin. The optimised proniosomal formulation showed enhanced transdermal flux of 16.15 μg/cm²/h as compared to 3.67 μg/cm²/h for drug dispersion. The developed formulations were observed as non-irritant to the rat skin and were found as quite stable at 4 and 25 °C for 90 days w.r.t. vesicle size and drug content. The dried proniosomal formulation could act as a promising alternative to niosomes and preferably for transdermal delivery of BCT.     

Practical Considerations for Compendial Method Selection

Abstract

The objective of this study was to develop and validate an in vitro test method that can be used as a tool for accessing batch-to-batch uniformity of finished topical products. The studies were performed by utilizing topical creams containing the 13-cis isomer of retinoic acid. Various physicochemical factors which may affect drug release from topical cream formulations were evaluated including drug concentration, internal phase droplet size distribution, viscosity and the composition of the emulsion internal and external phases. Utilizing a modified Franz diffusion cell with a cellulose membrane, the in vitro drug release profile from various cream formulations was established

The effect of varying the concentrations of various key ingredients by 30% does affect the viscosities and release rates compared to a standard formulation. However, there is no correlation between the viscosities and the release rates. No significant differences in pH and droplet size distribution were observed in these cream formulations compared to a standard formulation. The oil phase volume ratio appears to have the largest influence on the in vitro release of the drug. Intra- and inter-batch comparisons of the finished cream products show reproducible release profiles. Based on the results obtained in this study, when used together, both in vitro release and viscosity measurements may be useful as tools to assess batch-to-batch uniformity and consistent manufacturing of the finished cream product     

In situ forming implants for the delivery of metronidazole to periodontal pockets: formulation and drug release studies

This study was performed to obtain prolonged drug release with biodegradable in situ forming implants for the local delivery of metronidazole to periodontal pockets. The effect of polymer type (capped and uncapped PLGA), solvent type (water-miscible and water-immiscible) and the polymer/drug ratio on in vitro drug release studies were investigated. In situ implants with sustained metronidazole release and low initial burst consisted of capped PLGA and N-methyl-2-pyrolidone as solvent. Mucoadhesive polymers were incorporated into the in situ implants in order to modify the properties of the delivery systems towards longer residence times in vivo. Addition of the polymers changed the adhesiveness and increased the viscosity and drug release of the formulations. However, sustained drug release over 10 days was achievable. Biodegradable in situ forming implants are therefore an attractive delivery system to achieve prolonged release of metronidazole at periodontal therapy.     

Development and in vitro characterization of chitosan-coated polymeric nanoparticles for oral delivery and sustained release of the immunosuppressant drug mycophenolate mofetil

Objective: To develop an oral sustained release formulation of mycophenolate mofetil (MMF) for once-daily dosing, using chitosan-coated polylactic acid (PLA) or poly(lactic-co-glycolic) acid (PLGA) nanoparticles. The role of polymer molecular weight (MW) and drug to polymer ratio in encapsulation efficiency (EE) and release from the nanoparticles was explored in vitro.

Methods: Nanoparticles were prepared by a single emulsion solvent evaporation method where MMF was encapsulated with PLGA or PLA at various polymer MW and drug: polymer ratios. Subsequently, chitosan was added to create coated cationic particles, also at several chitosan MW grades and drug: polymer ratios. All the formulations were evaluated for mean diameter and polydispersity, EE as well as in vitro drug release. Differential scanning calorimetry (DSC), surface morphology, and in vitro mucin binding of the nanoparticles were performed for further characterization.

Results: Two lead formulations comprise MMF: high MW, PLA: medium MW chitosan 1:7:7 (w/w/w), and MMF: high MW, PLGA: high MW chitosan 1:7:7 (w/w/w), which had high EE (94.34% and 75.44%, respectively) and sustained drug release over 12?h with a minimal burst phase. DSC experiments revealed an amorphous form of MMF in the nanoparticle formulations. The surface morphology of the MMF NP showed spherical nanoparticles with minimal visible porosity. The potential for mucoadhesiveness was assessed by changes in zeta potential after incubation of the nanoparticles in mucin.

Conclusion: Two chitosan-coated nanoparticles formulations of MMF had high EE and a desirable sustained drug release profile in the effort to design a once-daily dosage form for MMF.     

Development of modified in situ gelling oral liquid sustained release formulation of dextromethorphan

Context: Alternative strategies are being employed to develop liquid oral sustained release formulation. These included ion exchange resin, sustained release suspensions and in situ gelling systems. The later mainly utilizes alginate solutions that form gels upon contact with calcium which may be administered separately or included in the alginate solution as citrate complex. This complex liberates calcium in the stomach with subsequent gellation. The formed gel can break after gastric emptying leading to dose dumping.

Objective: Development of modified in situ gelling system which sustain dextromethorphan release in the stomach and intestine.

Methods: Solutions containing alginate with calcium chloride and sodium citrate were initially prepared to select the formulation sustaining the release in the stomach. The best formulation was combined with chitosan. All formulations were characterized with respect to flow, gelling capacity, gelling strength and drug release.

Results: Increasing the concentration of alginate increased the gelling capacity and strength and reduced the rate of drug release in gastric conditions with 2% w/v alginate being the best formulation. However, these formulations failed to sustain the release in the intestinal conditions. Incorporation of chitosan with alginate increased the gelling capacity and strength and reduced the rate of drug release compared to alginate only system. The effect was optimum in formulation containing 1.5% w/v chitosan. The sustained release pattern was maintained both in the gastric and intestinal conditions and was comparable to that obtained from the marketed product.

Conclusion: Alginate-chitosan based in situ gelling system is promising for developing liquid oral sustained release.     

Amphotericin B-loaded solid lipid nanoparticles (SLNs) and nanostructured lipid carrier (NLCs): effect of drug loading and biopharmaceutical characterizations

The aim of this study was to further investigate the effect of drug loading, drug entrapment efficiency, the drug release profiles and biopharmaceutical point of views of amphotericin B (AmB) lipid formulations, that is, degree of aggregation by UV-spectroscopy, in vitro hemolytic and antifungal activities. The optimum drug loading was 2.5% by weight corresponded to lipid fraction in formulation. Increasing of the drug entrapment was achieved by blending small amount of phospholipid in solid lipid nanoparticle (SLN) dispersions. All AmB lipid dispersions were less aggregated species and hemolytic response than Fungizone^® indicating that lipid nanoparticles could reduce its toxicity. The sustained release profiles of AmB formulations depended on its aggregated form and entrapment efficiency. Too high AmB loaded (5% w/w) showed a biphasic drug release profile probably due to some amounts of drug deposited on the nanosphere surface including in continuous phase which promptly released. For in vitro antifungal testing, all AmB lipid formulations were equal and more effective than both AmB itself and Fungizone^®. These observations suggested that AmB loaded SLNs, nanostructured lipid carriers and modified SLNs by blending lecithin could enhance AmB solubility, prolong release characteristics, reduce toxicity and improve antifungal activity.     

In Vitro–In Vivo Characterization of Release Modifying Agents for Parenteral Sustained‐Release Ketorolac Formulation

One of the prerequisites for a parenteral preparation is that the excipients incorporated are biocompatible and biodegradable. In the present study hydrophilic and hydrophobic excipients were investigated for developing an intramuscular sustained‐release formulation of ketorolac. Kollidon® 17 PF, Peceol (glyceryl monooleate), and castor oil were chosen as the potential release‐retarding agents, each with a distinct mechanism of action. They were evaluated by in vitro drug‐release profiles and in vivo pharmacodynamic and pharmacokinetic study in mice. Cumulative drug release was determined for standard and test formulations in modified Franz diffusion cell. Pharmacodynamic parameter, T?=?70% response of peak analgesic response, was used to compare the performance of test formulations. Based on pharmacodynamic/pharmacokinetic correlation in the animal studies, Css_max and Css_min of 51.39 and 30.0 µg/mL, respectively, were determined and considered as performance markers for pharmacokinetic evaluation of test formulations. The study suggested that the sustained‐release capability of glyceryl monooleate was maximum followed by that of castor oil and Kollidon 17 PF, when compared to conventional ketorolac tromethamine formulation. It was inferred that water soluble excipient, though, showed release retarding property in vitro but could not maintain it in the in vivo environment. Glyceryl monooloeate‐based formulation produced the most favorable drug blood concentration vs. time profile.     

Development and evaluation of nanosized niosomal dispersion for oral delivery of Ganciclovir

Encapsulation of Ganciclovir in lipophilic vesicular structure may be expected to enhance the oral absorption and prolong the existence of the drug in the systemic circulation. So the purpose of the present study was to improve the oral bioavailability of Ganciclovir by preparing nanosized niosomal dispersion. Niosomes were prepared from Span40, Span60, and Cholesterol in the molar ratio of 1:1, 2:1, 3:1, and 3:2 using reverse evaporation method. The developed niosomal dispersions were characterized for entrapment efficiency, size, shape, in vitro drug release, release kinetic study, and in vivo performance. Optimized formulation (NG8; Span60:Cholesterol 3:2 molar ratio) has shown a significantly high encapsulation of Ganciclovir (89?±?2.13%) with vesicle size of 144?±?3.47?nm (polydispersity index [PDI]?=?0.08). The in vitro release study signifies sustained release profile of niosomal dispersions. Release profile of prepared formulations have shown that more than 85.2?±?0.015% drug was released in 24?h with zero-order release kinetics. The results obtained also revealed that the types of surfactant and Cholesterol content ratio altered the entrapment efficiency, size, and drug release rate from niosomes. In vivo study on rats reveals five-time increment in bioavailability of Ganciclovir after oral administration of optimized formulation (NG8) as compared with tablet. The effective drug concentration (>0.69 µg/mL in plasma) was also maintained for at least 8?h on administration of the niosomal formulation. In conclusion, niosomes can be proposed as a potential oral delivery system for the effective delivery of Ganciclovir.     

Folate-mediated solid–liquid lipid nanoparticles for paclitaxel-coated poly(ethylene glycol)

Background: As a promising anticancer drug, severe side-effects of current clinical formulations for paclitaxel have restricted its use, developing a better technical-economical formulation for paclitaxel delivery is needed. Method: In this study, the compound of folate-poly(ethylene glycol) (PEG)-phosphatidylethanolamine was synthesized and characterized with Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The solid-liquid lipid nanoparticle (SLLN) for paclitaxel modified with folate and poly(ethylene glycol) (folate-PEG-SLLN) was prepared and characterized. Morphology of folate-PEG-SLLN was examined by transmission electron microscopy. The particle size and zeta potential were performed by Zetapals. Encapsulation efficiency was analyzed by HPLC. The in vitro drug release of paclitaxel was investigated via membrane dialysis. The in vivo pharmacokinetics was measured with male Sprague-Dawley rats. Treatment efficiency was investigated with the mouse with sarcoma180 ascites tumor. Results: Paclitaxel loaded on the newly designed binary SLLN showed a longer and sustained in vitro releasing property. More importantly, S180 tumor-bearing mice treated with paclitaxel-loaded SLLN exhibited higher tumor inhibition rate, comparing with animals administered with paclitaxel injection alone (45.3% and 37.3%, respectively). Conclusion: The newly developed paclitaxel delivery system may have improved in vivo antitumor activity. The results demonstrated a great interest to use folate-mediated SLLN as a prospective drug delivery system for paclitaxel.     

Recent advances in ocular drug delivery

Amongst the various routes of drug delivery, the field of ocular drug delivery is one of the most interesting and challenging endeavors facing the pharmaceutical scientist. Recent research has focused on the characteristic advantages and limitations of the various drug delivery systems, and further research will be required before the ideal system can be developed. Administration of drugs to the ocular region with conventional delivery systems leads to short contact time of the formulations on the epithelium and fast elimination of drugs. This transient residence time involves poor bioavailability of drugs which can be explained by the tear production, non-productive absorption and impermeability of corneal epithelium. Anatomy of the eye is shortly presented and is connected with ophthalmic delivery and bioavailability of drugs. In the present update on ocular dosage forms, chemical delivery systems such as prodrugs, the use of cyclodextrins to increase solubility of various drugs, the concept of penetration enhancers and other ocular drug delivery systems such as polymeric gels, bioadhesive hydrogels, in-situ forming gels with temperature-, pH-, or osmotically induced gelation, combination of polymers and colloidal systems such as liposomes, niosomes, cubosomes, microemulsions, nanoemulsions and nanoparticles are discussed. Novel ophthalmic delivery systems propose the use of many excipients to increase the viscosity or the bioadhesion of the product. New formulations like gels or colloidal systems have been tested with numerous active substances by in vitro and in vivo studies. Sustained drug release and increase in drug bioavailability have been obtained, offering the promise of innovation in drug delivery systems for ocular administration. Combining different properties of pharmaceutical formulations appears to offer a genuine synergy in bioavailability and sustained release. Promising results are obtained with colloidal systems which present very comfortable conditions of use and prolonged action.     

Preparation,characterization, in vivo biodistribution and pharmacokinetic studies of donepezil-loaded PLGA nanoparticles for brain targeting

Objective: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder manifested by cognitive, memory deterioration and variety of neuropsychiatric symptoms. Donepezil is a reversible cholinesterase inhibitor used for the treatment of AD. The purpose of this work is to prepare a nanoparticulate drug delivery system of donepezil using poly(lactic-co-glycolic acid) (PLGA) for sustained release and efficient brain targeting.

Materials and methods: PLGA nanoparticles (NPs) were prepared by the solvent emulsification diffusion–evaporation technique and characterized for particle size, particle-size distribution, zeta potential, entrapment efficiency, drug loading and interaction studies and in vivo studies using gamma scintigraphy techniques.

Results and discussion: The size of drug-loaded NPs (drug polymer ratio 1:1) was found to be 89.67?±?6.43?nm. The TEM and SEM images of the formulation suggested that particle size was within 20–100?nm and spherical in shape, smooth morphology and coating of Tween-80 on the NPs was clearly observed. The release behavior of donepezil exhibited a biphasic pattern characterized by an initial burst release followed by a slower and continuous sustained release. The biodistribution studies of donepezil-loaded PLGA NPs and drug solution via intravenous route revealed higher percentage of radioactivity per gram in the brain for the nanoparticulate formulation as compared with the drug solution (p?Conclusion: The high concentrations of donepezil uptake in brain due to coated NPs may help in a significant improvement for treating AD. But further, more extensive clinical studies are needed to check and confirm the efficacy of the prepared drug delivery system.     

Preparation and evaluation of paclitaxel-loaded nanoparticle incorporated with galactose-carrying polymer for hepatocyte targeted delivery

Objective: Paclitaxel-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles incorporated with galactose-carrying polymer poly(vinyl benzyllactonamide) (PVLA) were prepared to facilitate the hepatocyte cell targeted delivery of paclitaxel via ligand-receptor mediated endocytosis. The factors impacting nanoparticle properties, drug release and cellular uptake efficiency were evaluated in vitro.

Method: Paclitaxel-loaded nanoparticles incorporated with PVLA were prepared by emulsion solvent evaporation method with polyvinyl alcohol (PVA) as co-emulsifier. The presence of PVLA on the particle surface was investigated through the change of ζ potential and surface hydrophobicity. Cellular uptake and cytotoxic activity, involving factors concerned with them, were evaluated by HepG2 cells in vitro.

Results: The presence of PVLA led to the increase of ζ potential, reduction of the particle surface hydrophobicity, slight promotion of paclitaxel encapsulation efficiency and more homogeneous particle size, but excessive PVLA accelerated the burst release. With enhanced attachment and cellular uptake efficiency, the PVLA incorporated nanoparticles exhibited significant cytotoxicity to HepG2 cells, and particles with higher PVLA-to-PLGA ratio, although had larger size and almost the same cellular uptake efficiency, performed much higher cytotoxic activity due to the larger drug capacity and faster release rate.     

Preparation and irradiation of Pluronic F127-based thermoreversible and mucoadhesive hydrogel for local delivery of naproxen

To improve physical properties and modulate the mucoadhesive hydrogel formulation via cross-linking by radiation, hydrogels were prepared using thermoreversible polymer Pluronic F127 (PF127) and mucoadhesive polymer carbopol 934P (C934P). As a model drug, naproxen was loaded in the hydrogel formulation. Sol-gel transition temperatures of hydrogels were measured by the tube-inversion method. The mucoadhesive potential of each formulation was determined by measuring the force required to detach the formulation from oral mucosal tissue. To strengthen the mechanical properties, the formulations were irradiated using an electronic beam. Drug release from the hydrogels and the cytotoxicity of each formulation were investigated. Sol-gel transition temperatures of the formulations were decreased by the addition of carbopol and were close to body temperature. The mucoadhesive force of the PF127 formulation was increased by addition of carbopol. In vitro release was sustained and the release rate was reduced by the addition of carbopol. After irradiation, the mucoadhesive force was increased about five-fold especially in the case of PF127 23% (9.7 kPa) and in vitro release was not sustained further. In conclusion, the use of a PF127 formulation incorporating a mucoadhesive polymer could effectively and safely improve oral residence time and absorption of naproxen. Irradiated formulations showed permanent cross-linking and improved properties.     

Fusogenic liposomal formulation of sirolimus: improvement of drug anti-proliferative effect on human T-cells

Context: Fusogenic liposomes are unique delivery vehicles capable of introducing their contents directly and efficiently into the cytoplasm.

Objective: The objective of this study was to evaluate the potential of fusogenic liposomes containing Sirolimus to improve its anti-proliferative effect on T-lymphocyte cells.

Materials and methods: Conventional liposomes containing Sirolimus were prepared from Dipalmitoylphosphatidylcholine (DPPC) and cholesterol using the modified ethanol injection method. To prepare fusogenic liposomes, dioleoylphosphatidylethanolamine (DOPE) was added to the conventional liposome formulation. The liposomes were characterized by their size, zeta potential, encapsulation efficiency percent (EE%) and chemical stability during 6 months. The in vitro release of liposomes, anti-proliferative effect and liposome uptake of both types of liposomes with optimized formulations were studied on human T-lymphocyte cells employing the MTT assay and fluorescein isothiocyanate-loaded liposomes.

Results and discussion: The particle size of the liposomes was evaluated between 138 and 650?nm and mean zeta potential was in the range of ?32.95 to ?45.60?mV. The average EE% of the prepared conventional and fusogenic liposomes were 76.9% and 80.5%, respectively. Liposomal formulations released only 10–20% of encapsulated drug without any burst effect. In vitro immunosuppressive evaluation on T-cells showed that fusogenic liposomes have the best anti-proliferative effects and uptake on T-lymphocyte cell compared to the conventional liposomes.

Conclusion: Our results indicated that fusogenic liposomes can be useful carriers for improving the inhibition of T-cell proliferation.     

Galactose decorated PLGA nanoparticles for hepatic delivery of acyclovir

The present study explores prospective of surface tailored nanoparticles for targeted delivery of acyclovir along with the interception of minimal side effects. Acyclovir loaded plain and galactosylated poly lectic co glycolic acid (PLGA) nanoparticles were efficiently prepared and characterized by Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), size, polydispersity index, zeta potential, and entrapment efficiency. The formulations were evaluated for in vitro drug release and hemolysis. Further, biodistribution study and fluorescent microscopic studies were carried out to determine the targeting potential of formulations. SEM revealed smooth morphology and spherical shape of the nanoparticles. In vitro, the galactosylated nanoparticles were found to be least hemolytic and exhibited a sustained release pattern. In vivo studies exhibited an augmented bioavailability, increased residence time and enhanced delivery of acyclovir to the liver upon galactosylation. It may therefore be concluded that galactose conjugated PLGA nanoparticles can be used suitably as vehicles for delivery of bioactives specifically to the hepatic tissues and may be thus exploited in the effective management of various liver disorders.