Remote loading in liposome: a review of current strategies and recent developments.

Liposomes have gained prominence as nanocarriers in drug delivery, and the number of products in the market is increasing steadily, particularly in cancer therapeutics. Remote loading of drugs in liposomes is a significant step in the translation and commercialization of the first liposomal product. Low drug loading and drug leakage from liposomes is a translational hurdle that was effectively circumvented by the remote loading process. Remote loading or active loading could load nearly 100% of the drug, which was not possible with the passive loading procedure. A major drawback of conventional remote loading is that only a very small percentage of the drugs are amenable to this method. Therefore, methods for drug loading are still a problem for several drugs. The loading of multiple drugs in liposomes to improve the efficacy and safety of nanomedicine has gained prominence recently with the introduction of a marketed formulation (Vyxeos) that improves overall survival in acute myeloid leukemia. Different strategies for modifying the remote loading process to overcome the drawbacks of the conventional method are discussed here. The review aims to discuss the latest developments in remote loading technology and its implications in liposomal drug delivery.

Enhanced skin penetration of Finasteride loaded DMSO-liposomes for the treatment of androgenic alopecia: comparison with conventional liposomes.

Long-term treatment with finasteride (FIN) for androgenic alopecia is restricted due to its systemic side effects. To address this problem, DMSO-modified liposomes were prepared in the present study to improve the topical delivery of FIN. DMSO-liposomes were prepared by a modification of the ethanol injection method. It was hypothesized that the permeation-enhancing property of DMSO could promote drug delivery to deeper skin layer where hair follicles are present. Liposomes were optimized by quality by design (QbD) approach and biologically evaluated in a rat model of testosterone-induced alopecia. Optimized DMSO-liposomes were spherical and had mean vesicle size, zeta potential, and entrapment efficiency of 330.1 ± 1.5, -14.52 ± 1.32, and 59.02 ± 1.12%, respectively. Biological evaluation on testosterone-induced alopecia and skin histology shows that follicular density and anagen/telogen (A/T) ratio were increased in rats treated with DMSO-liposomes as compared to FIN-liposomes without DMSO and an alcoholic solution of FIN applied topically. DMSO-liposomes could be promising skin delivery vehicles for FIN or similar drugs.

Sea surface temperature (SST) and SST anomaly (SSTA) datasets over the last four decades (1977-2016) during typhoon season (May to November) in the entire Global Ocean, North Pacific Ocean, Philippine Sea, South China sea, and Eastern China Sea.

The Sea Surface Temperature Anomalies (SSTA) are created for the chosen study period from 1977 to 2016 (40-years) including the base period from 1941 to 1970 (30-years) using the two different raw Sea Surface Temperature (SST) datasets named Optimum Interpolation (OI) SST version 2 and Centennial in situ Observation-Based Estimates (COBE) SST version 2. The SSTA and SST are measured for each month from May to November (typhoon activity months in the North West Pacific) over the entire Global Ocean, especially focusing on the North Pacific Ocean; Philippine Sea; South China Sea; and Eastern China Sea (the marginal Seas of the North West Pacific Ocean). The OI-SST V2 dataset is directly accessed by the online link https://psl.noaa.gov/, which is made available by the Physical Sciences Laboratory (PSL) of the National Oceanic and Atmospheric Administration (NOAA). OI-SST V2 dataset contains monthly-averaged SST data from December 1981 to May 2020. COBE-SST V2 dataset belongs to the Japan Meteorological Agency (JMA) and is also made available by the PSL of NOAA through the online link https://psl.noaa.gov/. COBE-SST V2 dataset contains a very long period of monthly-averaged SST data from January 1850 to December 2019. The SST data in both datasets are on a regular one-degree (1o) grid covering the entire Oceans of the Earth. Both datasets are in the Network Common Data Form (NetCDF)(.nc) and can be opened on any appropriate software platform like ESRI ArcGIS 10.5 for further analysis. All SST data presented in this article merely belong to the typhoon season months (from May to November) of the North West Pacific (NWP) Ocean basin and are thus crucial for typhoon-related research. At First, the SST data for each month from May to November over the whole study and the base periods are extracted for the entire Global Ocean. Then, for each successive 5-year period and 10-year period, the SST data is averaged separately for each month from May to November. Also, for the whole 40 years of the chosen current period and 30 years of the base period, the SST data is averaged separately for each month of the typhoon season. The successive year, 5-year, and 10-year SST data of the chosen current period is averaged for all seven months of typhoon season. Also, for the whole 40 years of the chosen current period and 30 years of the base period, the SST data is averaged over all seven months of typhoon season. Finally, the yearly, 5-yearly, 10-yearly, and monthly Sea Surface Temperature Anomalies (SSTA) are measured using the chosen current and base period data for the entire Global Ocean, North Pacific Ocean, Philippine Sea, South China sea, and Eastern China Sea. Statistical analyses are done, which are significant for global warming, SST, and typhoon-related research. For detailed analysis, explanation, and discussion, the readers are referred to the "Typhoon strength rising in the past four decades" [1].

Permeation enhancer nanovesicles mediated topical delivery of curcumin for the treatment of hyperpigmentation.

The main aim of the present study was to develop curcumin (CUR) loaded permeation enhancer-lipid vesicles for the treatment of hyperpigmentation. Hyperpigmentation is an acquired skin disorder characterized by uneven skin coloration, mainly in the regions of the facial skin, affecting millions of people worldwide. It often occurs in visible areas, hence causing significant negative psychological and social impacts. In the present study, curcumin-loaded permeation enhancer nanovesicles (PE-NVs) were developed by modified ethanol injection method and dimethyl sulfoxide was added as a penetration enhancer. PE-NVs were subjected to various physicochemical characterizations and drug permeation studies across the skin. The PE-NVs were tested for their efficacy in a sunlight-induced hyperpigmented rabbit skin model. Topical application of PE-NVs reduced symptoms of hyperpigmentation as compared with CUR methanolic solution because of higher accumulation because of better permeation into skin layers. Histopathological studies also confirmed the effectiveness of PE-NVs, since they reduced hyperpigmentation-induced lesions. Results confirmed that PE-NVs is a potential drug delivery system for topical administration drugs to treat skin-associated inflammatory disorders.

Phospholipid-polymer hybrid nanoparticle-mediated transfollicular delivery of quercetin: prospective implement for the treatment of androgenic alopecia.

Objectives: The aim of the study was to deliver effective doses of quercetin (Que) to the lower region of hair follicles (HFs) using the transfollicular route through dipalmotylphosphatidylcholine (DPPC)-reinforced poly lactide-co- glycolide nanoparticles (DPPC-PLGA hybrid NPs) for the treatment of alopecia. Method: PLGA and DPPC-PLGA hybrid NPs were prepared by double-emulsification solvent evaporation method. NPs were characterized for size, shape, zeta potential entrapment and drug release. Drug-polymer interactions were determined by infrared spectroscopy (Fourier transform infrared spectroscopy, FTIR) and differential scanning calorimetry (DSC). Follicular uptake of fluorescent marker tagged NPs was assessed on isolated rat skin by fluorescent microscopy. Potential of hybrid NPs to induce hair regrowth was tested on testosterone-induced alopecia in rat models by visual inspection, hair follicular density measurement (no./mm), and histological skin tissue section studies. Key findings: Hybrid NPs had mean vesicles size 339 ± 1.6, zeta potential -32.6 ± 0.51, and entrapment efficiency 78 ± 5.5. Cumulative drug release after 12 h was found to be 47.27 ± 0.79%. FTIR and DSC confirmed that drug was independently dispersed in the amorphous form in the polymer. Data from fluorescence microscopy suggested that NPs were actively taken up by HFs. In-vivo studies on alopecia-induced rat models showed that hybrid NPs improved hair regrowth potential of Que and accumulation of NPs at HFs end region inhibit HFs cells apoptosis. Conclusion: This study concludes that phospholipid-polymer hybrid NPs could be the promising transfollicular delivery system for Que in the treatment of androgenic alopecia management.

Novel Biomimetic Reconstituted Built-in Adjuvanted Hepatitis B Vaccine for Transcutaneous Immunization.

Transcutaneous immunization is the administration of a vaccine on the skin to generate efficient systemic and mucosal immune responses against an antigen. In the present study, reconstituted hepatitis B surface antigen vesicles (HBsAg-REVs) integrated with monophosphoryl lipid A were prepared by the delipidation-reconstitution method and tested as built-in adjuvanted vaccine, system for transcutaneous immunization using a combined approach of tape strippings, and enhanced antigen skin contact time. Prepared vesicles were extensively characterized for size, shape, zeta potential, and antigen protein loading efficiency. Following topical application, HBsAg-REVs skin permeation on isolated rat skin and cell uptake by bone marrow-derived dendritic cells were determined by confocal laser scanning microscopy and flow cytometry, respectively. The humoral and cellular immune responses elicited by HBsAg-REVs via transcutaneous immunization were comparable to the marketed intramuscular hepatitis B vaccine formulation with predefined immunization protocols. This study supports that delivery of reconstituted HBsAg vesicles via transcutaneous route may open a new vista for designing topical vaccines with possible immune protection against hepatitis B in future.

Development and characterization of HBsAg-loaded Eudragit nanoparticles for effective colonic immunization.

The present study was undertaken with an aim to investigate the potential of targeting colonic mucosa following oral vaccine delivery to generate prophylactic humoral and mucosal immune response. In present study, response surface methodology (RSM) using the central composite design (CCD) was applied for optimization of process and composition to get uniform, stable reproducible eudragit nanoparticles suitable for targeting to colon. The optimized formulation had the composition of 173 µg HBsAg, 250 mg polymers concentration (4:1 combination of Eudragit S-100 and L-100) and 2% w/v Polyvinyl alcohol (PVA) along with adjuvant Monophosphoryl lipid A (MPLA). Mean particle size of optimized nanoparticles was found to be 730.4 nm, entrapment efficiency (58.38%) and polydispersity index of 0.185. Fluorescent spectroscopy, differential scanning calorimetry, and antigen integrity by SDS-PAGE established that antigen structure was preserved during and after formulation development. In-vitro release studies in different intestinal pH concluded antigen release at mild alkaline conditions. Real time fluorescence animal imaging confirmed the effective absorption and distribution of NPs at colon resulted in improved immune response. Present study concludes that Eudragit nanoparticles offers strong potential in colon targeting of vaccines through oral immunization.

Chylomicron mimicking solid lipid nanoemulsions encapsulated enteric minicapsules targeted to colon for immunization against hepatitis B.

The oral route is one of the most convenient routes for drug and/or vaccine delivery. Yet variable nature of gastrointestinal tract due to transient changes in pH, physiology, and flora throughout the gut together with hostile nature of peptide drugs/vaccines when given by this route results in limited success. Colon targeting is a recent area of interest for most of the research among which hard gelatin coated capsules is one such important and useful contrivance. The present study assesses the mucosal immunization with HBsAg loaded lyophilized nanoparticles delivered in the colonic region using enteric coated minicapsules. Designed minicapsules offers better compliance and oral vaccine antigen delivery to the colonic region which involving mucosal exposure thus mimicking the natural pathogen entry in the body. The present study is an extension of our reported work where nanoparticles were administered to the colon through the rectal route. Lyophilized nanoparticles were characterized for particle size, in-vitro release and antigen integrity along with cell uptake study. Particles had ~241 ±â€¯32 nm sizes, flattened yet spherical in morphology. Enteric coated minicapsules were evaluated for size, coating thickness, and dissolution profile. In-vivo immune response assured its immunogenic potential with profound IgG (485 ±â€¯41 mIU/ml) and IgA (885 ±â€¯126 mIU/ml) antibody production as compared to marketed recombinant hepatitis B antigen formulation (Gene Vac-B®) which induce IgG and IgA titer; 1027 ±â€¯62 mIU/ml and 220 ±â€¯11 mIU/ml respectively following well established immunization protocol. Former induced significant mucosal immunity due to the involvement of Common Mucosal Immune System (CMIS). The study supports the workable novel approach for immune protection against hepatitis B.

Combined adjuvant-delivery system for new generation vaccine antigens: alliance has its own advantage.

Vaccines are a significant historical accomplishment in medical science due to its significance in saving millions of lives around the world with a manifold decline in disease burden and health expenditure. Since last decade, extensive efforts in vaccine design based on rational and experimental set up prompts the acknowledgement of several protective antigens; however, the utilization of those antigens as intense safe vaccines is still far beyond their discovery. The advancement of accomplished vaccines will need the combination of numerous strategies. In this way, the vaccine can be capable of provoking an abundant and effective immunization to compete against antigens with minimal/no adverse effects on recipients. First, stable and striking enough on the pharmaceutical point of view. Second, application of rational and realistic approaches to select an appropriate combination of adjuvant, antigen and delivery vehicle in the suitable formulation. Different vaccine adjuvants-delivery system combinations were discussed here elaborately, which are approved/licensed for human vaccines and are in various phases of clinical trials and pre-clinical trials. Challenges/limitations associated with vaccine designing and parameters to be considered, approaches to be applied, using available adjuvants are also detailed.

Development of Adjuvanted Solid Fat Nanoemulsions for Pulmonary Hepatitis B Vaccination.

Pulmonary vaccination is one of the most promising routes for immunization owing to its noninvasive nature and induction of strong mucosal immunity and systemic response. In the present study, recombinant hepatitis B surface antigen loaded solid fat nanoemulsions (SFNs) as carrier system and monophosphoryl lipid A as an adjuvant-carrier system was prepared and evaluated as multiadjuvanted vaccine system for deep pulmonary vaccination. Deposition and clearance from the deep lung of rats were determined by gamma scintigraphy. Biodistribution of SFNs was determined by the live animal imaging system. SFNs dispersion showed slower clearance as compared with sodium pertechnetate control solution (∗∗∗p <0.001) from the pulmonary region due to the virtue of particulate and hydrophobic nature of formulations. Humoral (sIgA and IgG) and cellular (IL-2 and IF-γ) immune responses were found to be significant (∗∗∗p <0.001) when compared with naïve antigen (recombinant surface antigen without any excipient) solution. Data indicate that deep pulmonary immunization offers a stronger immune response with balanced humoral, mucosal, and cellular immunization, which further needs to be tested in higher animals to support this hypothesis for clinical translation of this so far neglected yet potential target tissue for immunization.

Lipid A adjuvanted Chylomicron Mimicking Solid Fat Nanoemulsions for Immunization Against Hepatitis B.

Traditional parenteral recombinant hepatitis B virus (HBV) vaccines have effectively reduced the disease burden despite being able to induce seroprotective antibody titers in 5-10% vaccinated individuals (non-responders). Moreover, an estimated 340 million chronic HBV cases are in need of treatment. Development of safe, stable, and more effective hepatitis B vaccine formulation would address these challenges. Recombinant hepatitis B surface antigen (rHBsAg) entrapped solid fat nanoemulsions (SFNs) containing monophosphoryl lipid A (MPLA) that was prepared and optimized by quality by design (QbD) using response surface methodology (RSM), i.e., central composite design (CCD). Its immune potential was evaluated with preset immunization protocol in a murine model. Dose escalation study revealed that formulation containing 1 µg of rHBsAg entrapped SFNs with MPLA-induced significant higher humoral, and cellular response compared to the marketed vaccine (Genvac B) administered intramuscularly. SFNs with nanometric morphology and structural similarity with chylomicrons assist in improved uptake and processing to lymphatics. Moreover, the presence of an immunogenic component in its structure further augments delivery of rHBsAg to immune cells with induction of danger signals. This multi-adjuvant based approach explores new prospect for the dose sparing. Improved cellular immune response induced by this vaccine formulation suggests that it could be tested as an immunotherapeutic vaccine as well.

Protease loaded permeation enhancer liposomes for treatment of skin fibrosis arisen from second degree burn.

Cysteine protease (papain) is a plant derived enzyme and due to its collagenolytic activity has potential in fibrosis reduction. However, a major hurdle in its use as fibrosis reducing agent is to overcome stratum corneum skin barrier via topical application, owing to its hydrophilic and high molecular weight and protein nature which is prone to degradation. The aim of the present study was to develop a penetration enhancer incorporated drug delivery system, i.e. propylene glycol (PG) liposomes, loaded with papain for application in fibrosis therapy. Papain loaded PG-liposomes were prepared by the solvent injection method and characterized by size, shape, zeta potential, entrapment efficiency, drug release and stability. Papain conformational changes due to process stress were evaluated by electrophoresis and fluorescence spectroscopy. Biological evaluation was carried out in rodents by skin irritation and percent fibrosis reduction assays following induction of fibrosis arisen due to controlled second degree burn. Papain loaded PG-liposomes had mean vesicle size 180±30.3, zeta potential -25±1, polydispersity index 0.181 and 85±4.3% entrapment efficiency. Cumulative drug release after 8h was found to be 74.26±3.0%. SDS-PAGE and fluorescence spectroscopic studies confirmed the stability of papain after incorporation in PG-liposomes. Fibrosis reduction studies in animal models revealed that PG-liposomes incorporated papain improved fibrosis reduction significantly in comparison to conventional liposomes and free papain solution (p <0.05). Data suggest that propylene glycol incorporated liposomal system enhances papain proteolytic and collagenolytic activity along with a reduction in skin irritancy via preventing direct contact of papain with skin, improves papain therapeutic fibrosis reduction potential, an approach that may provide an efficient alternative for protease mediated fibrosis reduction in a variety of demanding circumstances.

Inhalable bioresponsive chitosan microspheres of doxorubicin and soluble curcumin augmented drug delivery in lung cancer cells.

In present investigation, doxorubicin (Dox) and soluble curcumin (Cur-2-HP-ß-CD-complex) combination was simultaneously loaded in inhalable bioresponsive chitosan microspheres (Dox/Cur-2-HP-ß-CD-complex-elastin-CMs) bearing a substrate-stimuli, elastin. The mean particle size and mean aerodynamic diameter of inhalable bioresponsive microspheres displayed noteworthy differences after incorporation of elastin. Moreover, combination of Dox and soluble curcumin was molecularly dispersed in microspheres matrix as substantiated by a range of spectral techniques. Inhalable bioresponsive microspheres released astonishingly higher amount of Dox in presence of elastase enzyme at pH∼5.5 in comparison to pH∼7.4. However, the release of soluble curcumin from tailored bioresponsive microspheres in presence of elastase enzyme was independent of pH. Consistently, inhalable bioresponsive microspheres exhibited outstandingly lower IC50 of 3.4-µM in comparison to 6.5-µM of inhalable drug loaded microspheres (Dox/Cur-2-HP-ß-CD-complex-CMs) bearing no elastin, against A549, non-small cell lung cancer cells. The superior therapeutic profile of inhalable bioresponsive microspheres may be attributed to enhanced drug release and consequently augmented drug exposure to A549 cells expressing elastase enzyme. In this way, stimuli triggered drug release from tailored inhalable bioresponsive microspheres boosted the phenomena of apoptosis in A549 cells. In conclusion, Dox/Cur-2-HP-ß-CD-complex-elastin-CMs warrant further in-vivo tumor regression study to prove its therapeutic efficacy.

Immunological evaluation of colonic delivered Hepatitis B surface antigen loaded TLR-4 agonist modified solid fat nanoparticles.

Hepatitis B is one of the leading liver diseases and remains a major global health problem. Currently available vaccines provide protection but often results in weaker/minimal mucosal immunity. Thus the present study is devoted to the development and in-vivo exploration of the colonically delivered biomimetic nanoparticles which capably enhance humoral as well as cellular immune response. In present work, Hepatitis B surface antigen (HBsAg) entrapped nanoparticles containing Monophosphoryl lipid A (MPLA) (HB+L-NP) were prepared by solvent evaporation method and characterized for particle size (~210nm), shape, zeta potential (-24mV±0.68), entrapment efficiency (58.45±1.68%), in-vitro release and antigen integrity. Dose escalation study was done to confirm prophylactic immune response following defined doses of prepared nanoparticulate formulations with or without MPLA. Intramuscular administered alum based marketed HBsAg (Genevac B) was used as standard (10µg) and were able to induce significant systemic (IgG) but remarkably low mucosal immune (IgA) response. Notably, HB+L-NP (0.5ml-10µg) induced strong systemic and robust mucosal immunity (510 and 470 mIU/ml respectively, p<0.001) from which mucosal was more significant due to the involvement of Common Mucosal Immune System (CMIS). Likewise, significant cellular immune response was elicited by HB+L-NP through T-cell activation (mixed Th1 and Th2) as confirmed by significantly increased cytokines level (IL-2 and Interferon-γ) in spleen homogenates. This study supports that delivery of HBsAg to the colon may open new vista in designing oral vaccines later being one of most accepted route for potential vaccines in future.

Tetanus toxoid-loaded cationic non-aggregated nanostructured lipid particles triggered strong humoral and cellular immune responses.

In the present investigation, non-aggregated cationic and unmodified nanoparticles (TT-C-NLPs4 and TT-NLPs1) were prepared of about 49.2 ± 6.8-nm and 40.8 ± 8.3-nm, respectively. In addition, spherical shape, crystalline architecture and cationic charge were also noticed. Furthermore, integrity and conformational stability of TT were maintained in both TT-C-NLPs4 and TT-NLPs1, as evidenced by symmetrical position of bands and superimposed spectra, respectively in SDS-PAGE and circular dichroism. Cellular uptake in RAW264.7 cells indicating the concentration-dependent internalisation of nanoparticles. Qualitatively, CLSM exhibited enhanced cellular uptake of non-aggregated TT-C-NLPs4 owing to interaction with negatively charged plasma membrane and clevaloe mediated/independent endocytosis. In last, in vivo immunisation with non-aggregated TT-C-NLPs4 elicited strong humoral (anti-TT IgG) and cellular (IFN-γ) immune responses at day 42, as compared to non-aggregated TT-NLPs1 and TT-Alum following booster immunisation at day 14 and 28. Thus, non-aggregated cationic lipid nanoparticles may be a potent immune-adjuvant for parenteral delivery of weak antigens.

Intravaginal administration of metformin hydrochloride loaded cationic niosomes amalgamated with thermosensitive gel for the treatment of polycystic ovary syndrome: In vitro and in vivo studies.

BACKGROUND AND OBJECTIVE: Metformin hydrochloride (MTF-HCl) is extensively recommended by physicians for the treatment of polycystic ovary syndrome (PCOS). Mechanistically, MTF-HCl activates AMP-dependent kinase-α (AMPK-α) pathway to decrease the glucose production, enhances fatty acid oxidation and elevates the uptake of glucose in tissues. However, despite favourable physicochemical properties, oral administration of MTF-HCl is associated with impaired bioavailability (50-60%), lactic-acidosis and frequent dosing (500mg 2-3 times a day) in PCOS that ultimately influence the patient compliance. Therefore, in present investigation, MTF-HCl loaded unmodified and cationic small unilamellar niosomes were separately amalgamated with thermosensitive gel (MTF-HCl-SUNs-Gel and MTF-HCl-C-SUNs-Gel) for the treatment of PCOS through vaginal route of administration. METHODS AND RESULTS: MTF-HCl-SUNs and MTF-HCl-C-SUNs were separately prepared by reverse phase evaporation method. The nanovesicle size and zeta-potential of MTF-HCl-C-SUNs were measured to be 210.3±14.8-nm (P<0.05) and +8.7±2.7-mV (P<0.001), significantly higher than 198.5±20.3-nm and -16.6±3.9-mV of MTF-HCl-SUNs, respectively. Moreover, promising results of in vitro characterization parameters like gelation time, gelling temperature, viscosity analysis, percent mucoadhesiveness and drug release of MTF-HCl-C-SUNs-Gel and MTF-HCl-SUNs-Gel ensured the candidature of tailored gels for further in vivo investigations. In this way, treatment of PCOS rats under scheduled dose-dosage regimen with oral MTF-HCl solution, intravaginal MTF-HCl-SUNs-Gel and intravaginal MTF-HCl-C-SUNs-gel exhibited remarkable alterations, recruitment and development of normal follicles in addition to normalization of level of various hormones in PCOS. CONCLUSION: In conclusion, MTF-C-SUNs-Gel has paved the way for developing intravaginal dosage form of MTF-HCl for the treatment of PCOS.

Vincristine sulfate loaded dextran microspheres amalgamated with thermosensitive gel offered sustained release and enhanced cytotoxicity in THP-1, human leukemia cells: In vitro and in vivo study.

Vincristine sulfate (VCS) is a drug of choice for the treatment of childhood and adult acute lymphocytic leukemia, Hodgkin's, non-Hodgkin's lymphoma as well as solid tumors including sarcomas. However, poor biopharmaceutical and pharmacokinetic traits of VCS like short serum half-life (12 min), high dosing frequency (1.4 mg/m(2) per week for 4 weeks) and extensive protein binding (75%) limit the clinical potential of VCS in cancer therapy. In present investigation, injectable vincristine sulfate loaded dextran microspheres (VCS-Dextran-MSs) were prepared and amalgamated with chitosan-ß-glycerophosphate gel (VCS-Dextran-MSs-Gel) to surmount the biopharmaceutical and pharmacokinetic limitations of VCS that consequently induced synergistic sustained release pattern of the drug. Particle size and zeta-potential of VCS-Dextran-MSs were measured to be 6.8 ± 2.4 µm and -18.3 ± 0.11 mV along with the encapsulation efficiency of about 60.4 ± 4.5%. Furthermore, VCS-Dextran-MSs and VCS-Dextran-MSs-Gel exhibited slow release pattern and 94.7% and 95.8% of the drug was released in 72 h and 720 h, respectively. Results from cell viability assay and pharmacokinetic as well as histopathological analysis in mice indicated that VCS-Dextran-MSs-Gel offers superior therapeutic potential and higher AUClast than VCS-Dextran-MSs and drug solution. In conclusion, VCS-Dextran-MSs-Gel warrants further preclinical tumor growth study to scale up the technology.

Nanoparticulate mediated transcutaneous immunization: Myth or reality.

Transcutaneous immunization (TCI) is a promising route of vaccine delivery through skin due to many well documented advantages. The main obstacle in TCI is the skin's top dead layer i.e. stratum corneum which is difficult to penetrate. Efficiently delivery of antigen to the immune competent cells of epidermis or dermis in TCI might elicit an effective immune response. In this review, skin immunology with a particular focus on potential of immunological active receptors in influencing adaptive immune responses is highlighted. The challenges with TCI and methods to improve it using different adjuvants, chemical and physical approaches, delivery systems, and combination of above methods to further improve immune response following skin application of antigen are elaborately discussed. Nanoparticulate vaccine delivery systems with reference to their applications in TCI are classified according to their chronological development. Conclusively, clinical translations of above methods are also briefly reviewed. FROM THE CLINICAL EDITOR: Transcutaneous immunization has been investigated by many as a promising route of vaccination. In this comprehensive review article, the authors described and discussed the existing knowledge and difficulties in this approach. Furthermore, ways of improving transcutaneous delivery were also reviewed.

Proteins and peptides: The need to improve them as promising therapeutics for ulcerative colitis.

The present review briefly describes the nature, type and pathogenesis of ulcerative colitis, and explores the potential use of peptides and proteins in the treatment of inflammatory bowel disease, especially ulcerative colitis. Intestinal absorption and the barrier mechanism of peptide and protein drugs are also discussed, with special emphasis on various strategies which make these drugs better therapeutics having high specificity, potency and molecular targeting ability. However, the limitation of such therapeutics are oral administration, poor pharmacokinetic profile and decreased bioavailability. The recent findings illustrated in this review will be helpful in designing the peptide/protein drugs as a promising treatment of choice for ulcerative colitis.

Development and validation of TLC-densitometric method for determination of lipid A adjuvant as a bulk and in solid fat nanoemulsions.

A simple, sensitive, selective and precise high-performance thin-layer chromatographic method was developed for determination of lipid A (MPLA) adjuvant as a bulk and in solid fat nanoemulsions. Chromatographic separations were performed on thin-layer chromatography aluminum plates precoated with silica gel 60 F-254 as stationary phase and chloroform-methanol-ethyl acetate solution (10:2:4, v/v/v) as mobile phase. With this solvent system, compact spots for MPLA at Rf value 0.80 ± 0.02 were obtained. Densitometric analysis of MPLA was carried out in absorbance mode at 357 nm. Linear regression analysis for the calibration plots showed good linear relationship with r = 0.9996 in the concentration range of 20-100 ng/spot. The mean values (±SD) of slope and intercept were found to be 7.355 ± 0.006 and 109.52 ± 0.170, respectively. Limits of detection (LOD) and quantitation (LOQ) were observed at 3.096 and 9.382 ng/spot, respectively.The method was validated for precision, accuracy, robustness and recovery as per the International Conference on Harmonization guidelines. Statistical analysis proved that the developed method for quantification of MPLA as a bulk and in solid fat nanoemulsions is reproducible, selective and economical. This method could be applied for quantitative assay of MPLA in lipid-based vaccine formulations.