Search

COVID-19 has posed a great threat to mankind, there is a dire need to introduce a vaccine to combat this global pandemic. Several vaccines are underway to complete their phase 3 clinical trials. This article highlights events surrounding the ongoing clinical trials of vaccines effective against COVID-19, and different procedures and formalities the vaccine will have to endure to get EUA. Clinical trials are discussed stepwise along with the clinical endpoint desired at the end of these trials. In line with antimicrobial resistance, vaccine resistance has also emerged in this era and needs focused consideration, and the probability of development of resistance in these vaccines is discussed. This article specifically covers the latest research reporting clinical efficacy, safety profile, and adverse events following the administration of doses to patients and concerns regarding the rushed approval of vaccines. Four vaccines have been discussed in detail; BNT162b2, mRNA-1273, Sputnik V, ChAdOx1.

Mannose receptors (MR) are highly over-expressed on macrophages in the inflammatory bowel disease (IBD) and can be targeted by developing mannose-anchored nano-carrier system. In this study, mannosylated chitosan (MC) polymer was synthesized because of its high affinity for mannose receptors. Afterward, MC nanoparticles (NPs) were fabricated encapsulating dexamethasone to target macrophages for attenuation of inflammation at initial stages. Further, NPs were coated with a pH-sensitive polymer to control the premature drug release in the stomach. NPs were optimized using a surface response quadratic model to study the impact of various process parameters. Optimized NPs were then characterized for size, morphology, zeta potential, surface chemistry, biocompatibility, and uptake by macrophages. The average particle size was found to be 380 ± 19.8 nm with an encapsulation efficiency of 78.1 ± 1.17%. pH-dependent drug release profile was obtained with an average release of 73.9 ± 5.24% over 72 h in simulated intestinal fluid (pH 7.4). Moreover, the NPs uptake by the macrophages supported the viability of macrophages with the NPs and did not show any adverse effects. Moreover, this study was supported by the uptake of NPs inside macrophages. Altogether, the data supported that MC NPs could serve as a potential anti-inflammatory therapeutic approach to target macrophages in IBD.

The present study aimed on the site specific delivery and enhanced in-vivo efficacy of antimonial drugs against the visceral leishmaniasis via macrophage targeted mannose anchored thiomer based nanoparticles. Mannose anchored thiolated nanoformulation [M-(CS-g-PEI)-TGA] was developed and evaluated in terms particle size, zeta-potential and entrapment efficacy. The TEM and EDX analysis was carried out to evaluate the morphology and successful entrapment of antimonial drug. Mucodhesion, permeation enhancement, oral pharmacokinetics, and in-vivo anti-leishmanial activity were carried out. The M-(CS-g-PEI)-TGA were found to be spherical having particle size of 287 ± 20 nm. Ex-vivo permeation indicated a 7.39-fold enhanced permeation of Meglumine Antimoniate with M-(CS-g-PEI)-TGA across Caco-2 cells compared to the Glucantime. Evaluation of in-vitro reduction in the parasitic burden via flow cytometric analysis indicated a 5.7-fold lower IC50 for M-(CS-g-PEI)-TGA compared to Glucantime. A 6.1-fold improvement in the oral bioavailability and 5.2-fold reduced parasitic burden in the L. donovani infected BALB/c mice model was observed with M-(CS-g-PEI)-TGA compared to Glucantime. The results encouraged the concept of M-(CS-g-PEI)-TGA nanoformulations as a promising strategy for oral therapy against visceral leishmaniasis.

The present study was intended to develop a papain grafted S-protected hyaluronic acid-lithocholic acid co-block (PAP-HA-ss-LCA) polymeric excipient as an amphiphilic muco permeating stabilizer for targeting breast cancer epithelial cells overexpressed with CD44 receptors. The mucopermeating, stabilizing and targeting capability of the PAP-HA-ss-LCA polymeric excipient was investigated by manufacturing tamoxifen (TMX) loaded self-nanoemulsifying drug delivery system (SNEDDS). TMX loaded PAP-HA-ss-LCA incorporated SNEDDS (TMX-PAP-HA-ss-LCA SNEDDS) were characterized for their surface chemistry, drug release, permeation enhancement, biocompatibility and antitumor activity. FTIR spectroscopic analysis showed successful synthesis of PAP-HA-ss-LCA polymer. X-ray diffraction (XRD) showed the amorphous form of TMX inside SNEDDS. The observed hydrodynamic diameter of TMX-PAP-HA-ss-LCA SNEDDS was 367.5 nm. Furthermore, Hyaluronic Acid-based Mucoadhesive Self Nanoemulsifying Drug Delivery System (SNEDDS) of TMX showed homogeneity in synthesis with low polydispersity and negative zeta potential due to stabilization with PAP-HA-ss-LCA polymer. The distinct spherical shape of the nanodroplets was evident by transmission electron microscopy (TEM). In vitro release kinetics indicated approximately >80% release within 48 h under sink conditions. Ex-vivo permeation study displayed 7.11-folds higher permeation of TMX by TMX-PAP-HA-ss-LCA in contrast to pure TMX. The biocompatibility study proved that SNEDDS formulation was safe and compatible against macrophages. In vitro cytotoxicity studies demonstrated that TMX-PAP-HA-ss-LCA SNEDDS could efficiently kill MCF-7 breast cancer cells as compared to the native TMX drug. Systemic toxicity studies proved the non-toxic nature of TMX-PAP-HA-ss-LCA in contrast to pure TMX. Based on these evidences, TMX-PAP-HA-ss-LCA SNEDDS formulation seems to be promising mucopermeating, augmented intracellular uptake with strong targeting potential for anti-proliferative activity.

INTRODUCTION: Infectious diseases associated with intracellular bacteria such as Staphylococcus aureus, Salmonella typhimurium and Mycobacterium tuberculosis are important public health concern. Emergence of multi and extensively drug-resistant bacterial strains have made it even more obstinate to offset such infections. Bacteria residing within intracellular compartments provide additional barriers to effective treatment. METHOD: Information provided in this review has been collected by accessing various electronic databases including Google scholar, Web of science, Scopus, and Nature index. Search was performed using keywords nanoparticles, intracellular targeting, multidrug resistance, Staphylococcus aureus; Salmonella typhimurium; Mycobacterium tuberculosis. Information gathered was categorized into three major sections as ‘Intracellular targeting of Staphylococcus aureus, Intracellular targeting of Salmonella typhimurium and Intracellular targeting of Mycobacterium tuberculosis’ using variety of nanocarrier systems. RESULTS: Conventional management for infectious diseases typically comprises of long-term treatment with a combination of antibiotics, which may lead to side effects and decreased patient compliance. A wide range of multi-functionalized nanocarrier systems have been studied for delivery of drugs within cellular compartments where bacteria including Staphylococcus aureus, Salmonella typhimurium and Mycobacterium tuberculosis reside. Such carrier systems along with targeted delivery have been utilized for sustained and controlled delivery of drugs. These strategies have been found useful in overcoming the drawbacks of conventional treatments including multi-drug resistance. CONCLUSION: Development of multi-functional nanocargoes encapsulating antibiotics that are proficient in targeting and releasing drug into infected reservoirs seems to be a promising strategy to circumvent the challenge of multidrug resistance. [Figure: see text]

Increasing drift in antimicrobial therapy failure against Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), and the advent of extended resistant strains strongly demand discovery of mechanisms underlying development of drug resistance. The emergence of resistance against anti-TB drugs has reached an alarming level in various parts of the world, providing an active platform for the design of new targeted drug delivery. Reactive oxygen species (ROS) have an important role in controlling TB pathogenesis. At macrophage activation, ROS that are produced inside macrophages directly kill resident bacteria. These ROS possess a dual character because they can kill macrophages along with the resident bacteria. Targeting these ROS can play a remarkable part in overcoming resistance of conventional drugs. Nanoparticles (NPs) have evolved as a potential drug carrier for targeted delivery and elimination of various resistance mechanisms against antimicrobials. Receptor-mediated targeting of macrophages via different NPs may be a promising strategy for combating drug resistance and enhancing efficacy of old-fashioned antimycobacterial agents.

There are many publications that deal with the administration of test substances to animals and the removal of blood samples for different objectives. The parenteral route of drug administration includes further different routes, i.e., drug administration through muscles (IM route) through veins (IV route) and through subcutaneous route. We can manage to check the outcomes of test substances within minutes when we go for the IV route as in this route; the drug directly goes to the systemic circulation. Different experimental animals are utilized to check the possible outcomes of test substances that include Rabbit, mice, and rat. Various factors like dose strength, dose frequency and the meaning by which drug can be administered to an animal can be examined. The emphasis on drug safety should be the main priority while injecting drug substances. Animal ethics guidelines should be followed in this regard. AEG basically provides us with safety guidelines that should be followed for safe handling.

We have demonstrated the enhanced in vivo oral efficacy and enhanced hepatoprotective effects of preactivated thiolated chitosan (Cht) nanoparticles (NPs) for tuberculosis. The mannose anchored preactivated thiolated chitosan nanoparticles (MPTCht-NPs) were prepared and characterized in terms of their particle size, in vitro entrapment efficiency (EE%) and zeta potential (mV). NPs were also evaluated in terms of mucoadhesion, % hemolysis, permeation enhancement, in vivo pharmacokinetics, toxicity and immunomodulation. NPs exhibited an average particle size of 307 nm with 19 folds enhanced permeation in comparison to conventional Rifampicin (Rif) formulation across everted rat intestine. The evaluation of in vivo pharmacokinetic parameters indicated 16 folds improvement in oral bioavailability in comparison to Rif alone following oral administration in rabbits. There was significant difference in the levels of serum transaminases, oxidative stress markers, and expression levels of anti-apoptotic (Bcl-2) and pro-apoptotic (Bax) genes between Rif treated and NPs treated groups. The serum transaminases levels were normal with MPTCht-NPs treated groups as compared to Rif treated groups while the levels of glutathione were markedly increased in MPTCht-NPs treated group. Furthermore, the levels of Bax were enhanced with the MPTCht-NPs treatment. In summary, these findings revealed that the designed NPs may act as promising therapeutic strategy against tuberculosis in a dose-dependent manner while providing the immunomodulation and hepatoprotective effect.

Aim: The present study evaluates the efficacy of paromomycin (PM)-loaded mannosylated thiomeric nanoparticles for the targeted delivery to pathological organs for the oral therapy of visceral leishmaniasis. Materials & methods: Mannosylated thiolated chitosan (MTC)-coated PM-loaded PLGA nanoparticles (MTC-PLGA-PM) were synthesized and evaluated for morphology, drug release, permeation enhancing and antileishmanial potential. Results: MTC-PLGA-PM were spherical in shape with a size of 391.24 ± 6.91 nm and an encapsulation efficiency of 67.16 ± 14%. Ex vivo permeation indicated 12.73-fold higher permeation of PM with MTC-PLGA-PM against the free PM. Flow cytometry indicated enhanced macrophage uptake and parasite killing in Leishmania donovani infected macrophage model. In vitro antileishmanial activity indicated 36-fold lower IC50 for MTC-PLGA-PM as compared with PM. The in vivo studies indicated 3.6-fold reduced parasitic burden in the L. donovani infected BALB/c mice model. Conclusion: The results encouraged the concept of MTC-PLGA-PM nanoparticles as promising strategy for visceral leishmaniasis.

The frequency of prostate cancer varies worldwide. Western people are more prone to this disease. Genetic changes and inflammation are the two most common causes of pathogenesis of prostate carcinoma. Genes taking part in progression of prostate cancer including GSTP1, RNASEL, PTEN/MXi1, AR gene pathway including PI3/AKT also leads to prostate cancer. Besides genes, inflammation, elevated VEGF, diet, environmental changes, and alteration in the androgen receptor are predisposing aspect for prostate cancer. The development of science and technology had led to astonishing modifications in treatment strategies. It is a slow-growing tumor and confined to the prostate only. The key objective of treatment is to reduce the level of testosterone. Different approaches are employed for treatment including hormonal therapy, cryosurgery, anti-tumor medication, and receptor-based treatment in which androgen receptors are major targets. The latest treatment of prostate cancer includes nanoparticle targeted delivery of antiandrogens.

There are a very large number of drugs that enter in the clinical trial phase but only a fraction of them is able to get their place in market. For a drug to reach at a phase of clinical trial requires a huge effort of research and a very large investment. Translational medicine, a relatively new discipline, uses the novel techniques that not only lower the risk of investment failure, but also focuses on reducing the testing duration in different phases of clinical trials. Discussed in the article are advantages of translational medicines and various challenges faced by translational medicine as well the ways by which this discipline will face these challenges. This article also focuses on recent advances in therapeutic development for diabetes, bone disorders, neurosciences, and oncology and the failures of translational medicine due to high external risk factors.

Fungal infections in immune-compromised patients are an important cause of mortality and morbidity. Amphotericin B (Amp B) is considered a powerful fungicidal drug but its clinical usage has certain limitations when administered intravenously due to its toxicity and poor solubility. In consideration of such challenges, in cutaneous leishmaniasis, the topical application of Amp B can be a safer option in many aspects. Thus, herein, biopolymer of polycaprolactone (PCL) nanoparticles (NPs) were developed with the loading of Amp B by nanoprecipitation for the treatment of topical leishmanial infections. Various parameters, such as concentration of PCL and surfactant Poloxamer 407, were varied in order to optimize the formation of nanoparticles for the loading of Amp B. The optimized formulation exhibited a mean hydrodynamic particle size of 183 nm with a spherical morphology and an encapsulation efficiency of 85%. The applications of various kinetic models reveal that drug release from nanoformulation follows Korsmeyer&ndash, Peppas kinetics and has a high diffusion exponent at a physiological pH of 7.4 as well a skin relevant pH = 5.5. The activity of the prepared nanoparticles was also demonstrated in Leishmania infected macrophages. The measured IC50 of the prepared nanoparticle formulation was observed to be significantly lower when compared to control free Amp B and AmBisome&reg, for both L. tropica KWH23 and L. donovani amastigotes in order to demonstrate maximum parasite inhibition. The prepared topical nanoformulations are capable of providing novel options for the treatment of leishmaniasis, which can be possible after in vivo assays as well as the establishment of safety profiles.

Microneedle patch is a prominent strategy with minimal invasion and painless application to improve skin penetration of drug molecules. Herein, we report microneedle patch (MNP) as an alternative to the oral route for the systemic delivery of tacrolimus (TM), an immunosuppressant drug. Thiolated chitosan (TCS) based microneedle patch was fabricated and characterized in vitro and in vivo for its mechanical strength, skin penetration, drug release, and skin irritation. The MNP having 225 needles with 575 μm showed good mechanical properties in terms of tensile strength and percentage elongation. The skin penetration showed 84% penetration with no breakage. Histology of the mice skin after insertion showed the penetration of needles into the dermis. In vitro release and ex vivo permeation studies through Franz diffusion cell showed the sustained release (82.5%) of TM from the MNP with significantly higher (p

The oral delivery of cancer chemotherapeutic drugs is challenging due to low bioavailability, gastrointestinal side effects, first-pass metabolism and P-glycoprotein efflux pumps. Thus, chemotherapeutic drugs, including Docetaxel, are administered via an intravenous route, which poses many disadvantages of its own. Recent advances in pharmaceutical research have focused on designing new and efficient drug delivery systems for site-specific targeting, thus leading to improved bioavailability and pharmacokinetics. A decent number of studies have been reported for the safe and effective oral delivery of Docetaxel. These nanocarriers, including liposomes, polymeric nanoparticles, metallic nanoparticles, hybrid nanoparticles, dendrimers and so on, have shown promising results in research papers and clinical trials. The present article comprehensively reviews the research efforts made so far in designing various advancements in the oral delivery of Docetaxel. Different strategies to improve oral bioavailability, prevent first-pass metabolism and inhibition of efflux pumping leading to improved pharmacokinetics and anticancer activity are discussed. The final portion of this review article presents key issues such as safety of nanomaterials, regulatory approval and future trends in nanomedicine research.

Salmonella typhi infections are difficult to treat due to poor penetration of current antibiotic ciprofloxacin (CIP) modalities into the intracellular compartments of macrophages owing to poor solubilization and oral bioavailability. Poor penetration and dissolution of CIP lead to development of intracellular pathogens induced multi-drug resistance and resistant biofilms formation. Here we developed a novel strategy for the design and development of mucopenetrating self-emulsifying drug delivery system (SEDDS) of CIP to target intracellular Salmonella typhi bacterium with high specificity and selectivity. Oleic oil, Tween 80, and PEG 200 were selected as oil, surfactant and co-surfactant based on solubilizing capacity and pseudo ternary diagram emulsification capability. Mucopenetration feature of the SEDDS was enhanced by inclusion of poly-L-lysine functionalized carbohydrates (mannose, preactivated hyaluronic acid) co-block pluronic F127 (PLL-M-PTHA-F127) polymeric excipient. PLL-M-PTHA-F127 was developed as an amphiphilic muco-penetrating targeted anti-bacterial biological entity for intracellular targeting of Salmonella typhi infection reservoirs. Characterization of these self-nanoemulsifying carriers was carried out via dynamic light scattering (DLS), transmission electron microscopy (TEM) and fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), x-ray diffraction (XRD) and thermogravimetric analysis (TGA) The observed hydrodynamic diameter of PLL-M-PTHA-F 127 self- nano emulsifying drug delivery system (SEDDS) was 247 nm with low PDI and negatively charged zeta potential showing the stabilization of as-prepared formulation. In vitro drug release kinetics of nanocarriers exhibited 85% sustained release within 72 h under sink conditions. PLL-M-PTHA-F127 SEDDS of CIP showed very strong killing capability against Salmonella typhi strains even at lowest concentrations as compared to CIP and were found to be hemocompatible and biocompatible. The intracellular Salmonella typhi survival rate has been minimized with PLL-M-PTHA-F127 SEDDS as compared to CIP alone. Fluorescence microscopy images confirmed the proficient cellular uptake within the intracellular compartment of macrophages and rapid gallstone biofilm dispersion/clearance activity as compared to other formulations and CIP. In summary, PLL-M-PTHA-F127-SEDDS of CIP seemed to be an ideal candidate for eradication of Salmonella typhi intracellularly.

The study was aimed to improve the aqueous solubility of atorvastatin (AT) and ameliorate permeability of metformin (MT) in a combination formulation, improving their oral bioavailability. Several AT-MT loaded polyvinylpyrrolidone (PVP) and hyaluronic acid (HA) based nanoparticles were prepared through electrospraying method (ES-NPs), and tested for physicochemical, in vitro, and in vivo parameters. Among the trialed formulations, a sample consisting of AT, MT, PVP, and HA at the weight ratio of 1/6.25/3.75/15 furnished the most satisfying solubility and release rate results. It enhanced approximately 10.3-fold and 3.6-fold solubility of AT as compared with AT powder and marketed product (Lipilow) in phosphate buffer pH = 6.8, respectively. Whereas, permeation of MT was 1.60-fold and 1.47-fold improved as compared with MT powder and marketed product (Glucophage), respectively. As compared with Lipilow, AUC (0-∞) and Cmax of AT with ES-NPs in rats were improved to 3.6-fold and 3.2-fold, respectively. Similarly, as compared with Glucophage, AUC (0-∞) and Cmax of MT were improved to 2.3-fold and 1.8-fold, respectively. Thus, ES-NPs significantly enhanced the solubility of AT (a BCS class II drug) and permeability of MT (a BCS class III drug) and might be a promising drug delivery system for co-delivery of these drugs.

Pharmacokinetics can be defined as what the body does to a drug. The basic parameters of pharmacokinetics are discussed here including absorption, distribution, metabolism, and excretion. Characteristics and pathways taken by these drugs are determined by these parameters. The mechanism followed by these parameters are also discussed. Furthermore, the factors affecting these parameters including physicochemical factors, physical factors and pharmaceutical factors are also explored. Different routes of drug absorption and main barriers to drug distribution are also explained. The pharmacokinetic values namely acid dissociation constant, bioavailability and solubility are briefly explained. There is a detailed insight into the pathways of metabolism (Phase I and II reactions) and excretion.

Background and Objectives: Lipid-based self-nanoemulsifying drug delivery systems (SNEDDS) have resurged the eminence of nanoemulsions by modest adjustments and offer many valuable opportunities in drug delivery. Chlorpromazine, an antipsychotic agent with poor aqueous solubility&mdash, with extensive first-pass metabolism&mdash, can be a suitable candidate for the development of SNEDDS. The current study was designed to develop triglyceride-based SNEDDS of chlorpromazine to achieve improved solubility, stability, and oral bioavailability. Materials and Methods: Fifteen SNEDDS formulations of each short, medium, and long chain, triglycerides were synthesized and characterized to achieve optimized formulation. The optimized formulation was characterized for several in vitro and in vivo parameters. Results: Particle size, zeta potential, and drug loading of the optimized SNEDDS (LCT14) were found to be 178 &plusmn, 16, &minus, 21.4, and 85.5%, respectively. Long chain triglyceride (LCT14) showed a 1.5-fold increased elimination half-life (p &lt, 0.01), up to 6-fold increased oral bioavailability, and 1.7-fold decreased plasma clearance rate (p &lt, 0.01) compared to a drug suspension. Conclusion: The findings suggest that SNEDDS based on long-chain triglycerides (LCT14) formulations seem to be a promising alternative for improving the oral bioavailability of chlorpromazine.

To achieve remotely directed delivery of anticancer drugs, surface-decorated nanoparticles with ligands are reported. In this study, folic acid– and thiol-decorated chitosan nanoparticles loaded with docetaxel (DTX-NPs) were prepared for enhanced cellular internalization in cancer cells and improved oral absorption. The DTX-NPs were explored through in vitro and in vivo parameters for various parameters. The DTX-NPs were found to be monodisperse nanoparticles with an average particle size of 158.50 ± 0.36 nm, a polydispersity index of 0.36 ± 0.0, a zeta potential of + 18.30 ± 2.52 mV, and an encapsulation efficiency of 71.47 ± 5.62%. The drug release from DTX-NPs followed the Korsmeyer-Peppas model with about 78% of drug release in 12 h. In in vitro cytotoxicity studies against folate receptor, positive MDA-MBB-231 cancerous cells showed improved cytotoxicity with IC50 of 0.58 μg/mL, which is significantly lower as compared to docetaxel (DTX). Ex vivo permeation enhancement showed an efflux ratio of 0.99 indicating successful transport across the intestine. Oral bioavailability was significantly improved as Cmax and AUC were higher than DTX suspension. Overall, the results suggest that DTX-NPs can be explored as a promising carrier for oral drug delivery.

Background and objectives: Turmeric has assisted in the control of inflammation and pain for decades and has been used in combination with other nutraceuticals to treat acute and chronic osteoarthritis pain. Recently, the effect of turmeric, turmeric extract, or curcuminoids on musculoskeletal pain, either by themselves or in conjunction with other substances, has been reported. The aim of this study was to develop and characterize turmeric nanoparticles (T-NPs) for various parameters, both in vitro and in vivo. Materials and Methods: The T-NPs were successfully synthesized and characterized using particle size analysis, solubility improvement, SEM, EDX, X-ray diffraction, and in vivo antigout activity in mice model. Results: The T-NPs were of about 46 nm in size with a positive zeta potential +29.55 ± 3.44 and low polydispersity index (PDI) (0.264). Furthermore, the diseased mice, with induced gout via monosodium urate crystals, were treated with 5, 10, and 20 ppm T-NPs, administered orally, and the anti-gout potential was observed through measurement of joint diameter and changes in biochemical parameters, including lipid profile, renal function test, and liver function tests which significantly reduced the levels of these biochemical parameters. Conclusions: Uric acid levels were significantly reduced after the treatment with T-NPs. indicating that T-NPs show superior potential against gout management. Thus, T-NPs can be developed as an efficient antigout agent with minimum toxicities.

Resealed erythrocytes have been explored in various dimensions of drug delivery, owing to their high biocompatibility and inability to initiate immune response. The present research was designed to evaluate the drug delivery potential of erythrocytes by loading a hydrophobic anti-malarial drug, Artemether. Three different loading techniques were applied to achieve maximum optimized drug loading. A HPLC method was validated for drug quantification in erythrocytes. The relatively high loading was achieved using hypotonic treatment was 31.39% as compared to other two methods. These, drug loaded erythrocytes were characterized for membrane integrity via ESR showing higher ESR values for drug loaded cells as compared to normal cells. Moreover, microscopic evaluation was done to observe morphological changes in erythrocytes after successful loading which showed swollen cells with slight rough surface as compared to smooth surface of normal cells. Drug release was studied for 8 h which showed more than 80% release within 3-7 h from erythrocytes treated with different hypotonic methods. Overall, the study revealed a potential application of erythrocytes in delivery of hydrophobic drugs using hypotonic treatment as compared to other methods.

Post-operative surgical site infections (SSI) present a serious threat and may lead to complications. Currently available dressings for SSI lack mucoadhesion, safety, efficacy and most importantly patient compliance. We aimed to address these concerns by developing a bioactive thiolated chitosan-alginate bandage embedded with zinc oxide nanoparticles (ZnO-NPs) for localized topical treatment of SSI. The FTIR, XRD, DSC and TGA of bandage confirmed the compatibility of ingredients and modifications made. The porosity, swelling index and lysozyme degradation showed good properties for wound healing and biodegradation. Moreover, in-vitro antibacterial activity showed higher bactericidal effect as compared to ZnO-NPs free bandage. In-vivo wound healing in murine model showed significant improved tissue generation and speedy wound healing as compared to positive and negative controls. Over all, thiolated bandage showed potential as an advanced therapeutic agent for treating surgical site infections, meeting the required features of an ideal surgical dressing.

The bacterial pathogen Salmonella typhi (S. typhi) causes a severe systemic disease in humans called typhoid fever, which is a major public health issue of global importance. Ciprofloxacin has an excellent sterilizing effect on the biliary and fecal reservoirs of chronic carriers of S. typhi in comparison to conventional antibiotics such as ampicillin. Despite of recent development of resistance in S. typhi strains as well as resistant biofilms, delivery systems of such drugs, controlled and targeted release of antibiotic modalities remain a big challenge. The development of novel therapeutic delivery formats to treat S. typhi is urgently required. Therefore, advanced targeted nanocarriers based on carbohydrates polymers, lipids and metals proves to be most effective way of treating S. typhi infection. Diagnosis of typhoid is challenging owing to the vast existence of gaps accompanying over-testing, over-diagnosis, over-treatment, non-specificity and heterogenous nature of virulent S. typhi strains.Therefore there is need for new biosensing approaches for detection and diagnosis of S.typhi strands for mininmizing the dosage and resistance of antibiotic modalities . Recently developed nano scale based biosensors have been in used for detection of S. typhi pathogen. Moreover, there is need to focus on principle and application that could be targetd for diagnosis of S.typhi. In summary, nanomaterials seemed to be an ideal candidate for eradication as well as diagnosis of S. typhi intracellularly.

The antibiotic drug resistance in Mycobacterium tuberculosis (M.tb) is typically associated with immune evasion shared by pathogenic bacterium and intrinsic antimycobacterial drug resistance. These factors significantly contribute to the limited delivery of drugs intracelullary thereby posing an ever-growing threat to mankind. A promising approach to tackle this multi-drug resistance is to use nanocargoes (NCs) based drug delivery approach. The aim of the present study was to develop mannose coated S-protected thiomeric site-specific nanocargoes (MPTCh-NCs) of Rifampicin (Rif) in order to deliver drug locally inside the macrophages. This NCs-based delivery system modifies the macrophage activation states via mannose receptors and endocytosis to alter the macrophage activation state thus providing synergistic antimycobacterial effects. MPTCh-NCs were synthesized by ionic gelation method and assessed for particle size and encapsulation efficiency Moreover, MPTCh-NCs were also investigated in in vitro for drug release, macrophage uptake, buffering potential, Mycothione reductase (MTR) inhibition ability, minimum inhibitory concentration (MIC), phagolysosomal fusion, reactive oxygen species (ROS) production apoptosis and RV 1258 inhibition. The in vivo bioavailability study of MPTCh-NCs was also evaluated in male BALB/c models over a period of 72 h. The optimized MPTCh-NC formulation was nanosized (390 ± 20 nm) with better EE of Rif i.e. 73.68 ± 5.99%. The MPTCh-NCs showed better buffering capacity at different pH ranges, 35.69 folds higher macrophage uptake than Rif with P-gp inhibition potential and pronounced MTR inhibition potential. The MPTCh-NCs exhibited MIC of 16 μg/ml by drug susceptibility testing. Flow cytometric analysis of MPTCh-NCs exhibited, increased apoptosis (33.29%). Real time PCR data suggested enhanced RV 1258 inhibition potential (0.387 fold expression) of the MPTCh-NCs. In vivo results indicated increased bioavailability of MPTCh-NCs (AUC 12.31 folds higher) in comparison to conventional drug Rif. In summary, the observed capacity of the mannose coated S-protected NCs-based approach to deliver therapeutic levels of Rif selectively has potential to improve the therapeutic management against drug resistant tuberculosis.

Hirudin is clinically an important drug used for the treatment of cardiac diseases, but has never been elucidated for antileishmanial potential. This study was designed to determine the therapeutic utility of hirudin against leishmaniasis. Binding affinities of 28 potent proteinase inhibitors were screened computationally against leishmanolysin (GP63), out of which hirudin exhibited higher binding affinity with GP63 and good expected IC50 values. Experimentally, hirudin showed most promising activity against promastigote and axenic amastigote forms of leishmanial parasites with IC50 values of 0.60 ± 0.36 μg/mL and 0.43 ± 0.23 μg/mL, respectively, in a dose- and time-dependent assay. The cytotoxicity assay revealed no adverse effects on human macrophages with LD50 value of 860.11 ± 53.44 μg/mL. Hirudin caused leishmanial cell death mainly by apoptosis and membrane permeability. In spite of the basic knowledge obtained, hirudin mechanism is considerably less prone to the induction of resistance than classical drugs. Collectively, this study fosters further studies for the hirudin as new antileishmania lead with a new mode of action.

Akhtar Nadhman,1–3 Malik Ihsanullah Khan,1,2 Samina Nazir,4 Momin Khan,1,5 Gul Shahnaz,6 Abida Raza,2 Dilawar Farhan Shams,7 Masoom Yasinzai1,3 1Department of Biotechnology, Faculty of Biological Sciences, Quaid-i-Azam University, 2Nuclear Medicine Oncology and Radiotherapy Institute, 3Centre for Interdisciplinary Research in Basic Sciences (CIRBS), International Islamic University, 4Nanosciences and Catalysis Division, National Centre for Physics, Quaid-i-Azam University Campus, Islamabad, 5Department of Microbiology, Institute of Basic Medical Sciences, Khyber Medical University, Peshawar, 6Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 7Department of Environmental Sciences, Abdul Wali Khan University Mardan, Mardan, Pakistan Abstract: Lipid and protein oxidation are well-known manifestations of free radical activity and oxidative stress. The current study investigated extermination of Leishmania tropica promastigotes induced by lipid and protein oxidation with reactive oxygen species produced by PEGylated metal-based nanoparticles. The synthesized photodynamic therapy-based doped and nondoped zinc oxide nanoparticles were activated in daylight that produced reactive oxygen species in the immediate environment. Lipid and protein oxidation did not occur in dark. Themajor lipid peroxidation derivatives comprised of conjugated dienes, lipid hydroperoxides, and malondialdehyde whereas water, ethane, methanol, and ethanol were found as the end products. Proteins were oxidized to carbonyls, hydroperoxides, and thiol degrading products. Interestingly, lipid hydroperoxides were produced by more than twofold of the protein hydroperoxides, indicating higher degradation of lipids compared to proteins. The in vitro evidence represented a significant contribution of the involvement of both lipid and protein oxidation in the annihilated antipromastigote effect of nanoparticles. Keywords: lipid peroxidation, protein oxidation, Leishmania tropica, zinc oxide (ZnO), nanoparticles, reactive oxygen species (ROS), photodynamic therapy (PDT), doping

Despite of the remarkable cytotoxic and imaging potential of ultra-small metal nanoclusters, their toxicity-free and targeted delivery to cancerous cells remains a substantial challenge that hinders their clinical applications. In this study, a polymeric scaffold was first synthesized by grafting folic acid and thiol groups to chitosan (CS) for cancer cell targeting and improved gastric permeation. Furthermore, silver nanocluster (Ag NCs) were synthesized in situ, within CS scaffold by microwave irradiation and core-shell nanocapsules (NCPs) were prepared with hydrophobic docetaxel (DTX) in the core and Ag NCs embedded CS in the shell. A significant cytotoxicity synergism (~300 folds) was observed for DTX with co-delivery of Ag NCs against breast cancer MDA-MB-231 cells. Following oral administration, the DTX-Ag-NCPs increased bioavailability due to enhanced drug transport across gut (9 times), circulation half-life (~6.8 times) and mean residence time (~6.7 times), as compared to the control DTX suspension. Moreover, 14 days acute oral toxicity of the DTX-Ag-NCPs was performed in mice and evaluated for changes in blood biochemistry parameters, organ to body weight index and histopathology of liver and kidney tissues that revealed no significant evidence of toxicity suggesting the safety and efficiency of the DTX-Ag-NCPs as hybrid nanocarrier for biocompatible delivery of metal nanoclusters.

The aim of this study was to evaluate mannose-anchored thiolated chitosan (MTC) based nanocarriers (NCs) for enhanced permeability, improved oral bioavailability and anti-parasitic potential of amphotericin B (AmB). Transgenic Leishmania donovani parasites expressing red fluorescent protein DsRed2 and imaging-flow cytometry was used to investigate parasitic burdens inside bone marrow-derived macrophages ex vivo. Cytokine estimation revealed that MTC nanocarriers activated the macrophages to impart an explicit immune response by higher production of TNF-α and IL-12 as compared to control. Cells treated with MTC NCs showed a significantly higher magnitude of nitrite and propidium iodide (PI) fluorescence intensity in contrast to cells treated with AmB. Concerning to apparent permeability coefficient (Papp) results, the MTC NCs formulation displayed more specific permeation across the Caco-2 cell monolayer as compared to AmB. The half-life of MTC NCs was about 3.3-fold persistent than oral AmB used as positive control. Also, t oral bioavailability of AmB was increased to 6.4-fold for MTC NCs compared to AmB for positive control. Acute oral evaluation indicated that MTC NCs were significantly less toxic compared to the AmB. Based on these findings, MTC NCs seems to be promising for significant oral absorption and improved oral bioavailability of AmB in leishmaniasis chemotherapy.

Aim: Our aim was to inhibit trypanothione reductase (TR) and P-gp efflux pump of Leishmania by the use of thiolated polymers. Thus, increasing the intracellular accumulation and therapeutic effectiveness of antimonial compounds. Methods: Mannosylated thiolated chitosan and mannosylated thiolated chitosan-polyethyleneimine graft were synthesized and characterized. Meglumine antimoniate-loaded nanoparticles were prepared and evaluated for TR and P-gp efflux pump inhibition, biocompatibility, macrophage uptake and antileishmanial potential. Results: Thiomers inhibited TR with Ki 2.021. The macrophage uptake was 33.7- and 18.9-fold higher with mannosylated thiolated chitosan-polyethyleneimine graft and mannosylated thiolated chitosan nanoparticles, respectively, as compared with the glucantime. Moreover, the in vitro antileishmanial activity showed 14.41- and 7.4-fold improved IC50 for M-TCS-g-PEI and M-TCS, respectively as compared with glucantime. Conclusion: These results encouraged the concept that TR and P-gp inhibition by the use of thiomers improves the therapeutic efficacy of antimonial drugs.

We describe daylight responsive silver (Ag) doped semiconductor nanoparticles of zinc oxide (DSNs) for photodynamic therapy (PDT) against Leishmania. The developed materials were characterized by X-ray diffraction analysis (XRD), Rutherford backscattering (RBS), diffused reflectance spectroscopy (DRS), and band-gap analysis. The Ag doped semiconductor nanoparticles of zinc oxide were PEGylated to enhance their biocompatibility. The DSNs demonstrated effective daylight response in the PDT of Leishmania protozoans, through the generation of reactive oxygen species (ROS) with a quantum yield of 0.13 by nondoped zinc oxide nanoparticles (NDSN) whereas 0.28 by DSNs. None of the nanoparticles have shown any antileishmanial activity in dark, confirming that only ROS produced in the daylight were involved in the killing of leishmanial cells. Furthermore, the synthesized nanoparticles were found biocompatible. Using reactive oxygen species scavengers, cell death was attributable mainly to 77-83% singlet oxygen and 18-27% hydroxyl radical. The nanoparticles caused permeability of the cell membrane, leading to the death of parasites. Further, the uptake of nanoparticles by Leishmania cells was confirmed by inductively coupled plasma atomic emission spectroscopy (ICP-AES). We believe that these DSNs are widely applicable for the PDT of leishmaniasis, cancers, and other infections due to daylight response.

Polymeric nanomaterials, hybridized with lipid components, e.g. phosphocholine or fatty acids, are currently being explored for efficient nano-platforms for hydrophobic drugs. However, their toxicology and toxicokinetics need to be established before enabling their clinical potential. The aim of this study was to investigate the toxicological profile of thiomer enveloped hybrid nanoliposomes (ENLs) and bare nanoliposomes (NLs), loaded with docetaxel (DTX) hydrophobic drug, biocompatible nano-carriers for therapeutic cargo. The in vitro toxicity of hybrid ENLs and NLs was evaluated towards the HCT-116 colon cancer cell line. Biocompatibility was explored against macrophages and acute oral toxicity was examined in mice for 14 days. The anticancer IC50 for ENLs was 0.148 μg ml−1 compared with 2.38 μg ml−1 for pure docetaxel (DTX). The human macrophage viability remained above 65% and demonstrated a high level of biocompatibility and safety of ENLs. In vivo acute oral toxicity showed slight changes in serum biochemistry and haematology but no significant toxicities were observed referring to the safety of DTX loaded hybrid ENLs. On histological examination, no lesions were determined on the liver, heart and kidney. These studies showed that hybrid ENLs can serve as a safe and biocompatible platform for oral delivery of hydrophobic drugs.

Aim: Our goal was to improve treatment outcomes for visceral leishmaniasis by designing nanocarriers that improve drug biodistribution and half-life. Thus, long-acting mannose-anchored thiolated chitosan amphotericin B nanocarrier complexes (MTC AmB) were developed and characterized. Materials & methods: A mannose-anchored thiolated chitosan nanocarrier was manufactured and characterized. MTC AmB was examined for cytotoxicity, biocompatibility, uptake and antimicrobial activities. Results: MTC AmB was rod shaped with a size of 362 nm. MTC AmB elicited 90% macrophage viability and 71-fold enhancement in drug uptake compared with native drug. The antileishmanial IC50 for MTC AmB was 0.02 μg/ml compared with 0.26 μg/ml for native drug. Conclusion: These studies show that MTC can serve as a platform for clearance of Leishmania in macrophages.

The purpose of this study was to develop a microparticulate formulation for nasal delivery of exenatide utilizing a thiolated polymer. Poly(acrylic acid)-cysteine (PAA-cys) and unmodified PAA microparticles loaded with exenatide were prepared via coprecipitation of the drug and the polymer followed by micronization. Particle size, drug load and release of incorporated exenatide were evaluated. Permeation enhancing properties of the formulations were investigated on excised porcine respiratory mucosa. The viability of the mucosa was investigated by histological studies. Furthermore, ciliary beat frequency (CBF) studies were performed. Microparticles displayed a mean size of 70-80 µm. Drug encapsulation was ∼80% for both thiolated and non-thiolated microparticles. Exenatide was released from both thiolated and non-thiolated particles in comparison to exenatide in buffer only within 40 min. As compared to exenatide dissolved in buffer only, non-thiolated and thiolated microparticles resulted in a 2.6- and 4.7-fold uptake, respectively. Histological studies performed before and after permeation studies showed that the mucosa is not damaged during permeation studies. CBF studies showed that the formulations were cilio-friendly. Based on these results, poly(acrylic acid)-cysteine-based microparticles seem to be a promising approach starting point for the nasal delivery of exenatide.

Leishmaniasis is a complex of diseases with numerous clinical manifestations for instance harshness from skin lesions to severe disfigurement and chronic systemic infection in the liver and spleen. So far, the most classical leishmaniasis therapy, despite its documented toxicities, remains pentavalent antimonial compounds. The arvailable therapeutic modalities for leishmaniasis are overwhelmed with resistance to leishmaniasis therapy. Mechanisms of classical drug resistance are often related with the lower drug uptake, increased efflux, the faster drug metabolism, drug target modifications and over-expression of drug transporters. The high prevalence of leishmaniasis and the appearance of resistance to classical drugs reveal the demand to develop and explore novel, less toxic, low cost and more promising therapeutic modalities. The review describes the mechanisms of classical drug resistance and potential drug targets in Leishmania infection. Moreover, current drug-delivery systems and future perspectives towards Leishmaniasis treatment are also covered.

Background: The objective of this study was to develop and evaluate a more effective mucoadhesive thiomer for buccal drug-delivery systems. Methods: 2-iminothiolane was covalently attached to a chitosan backbone. A preactivation step followed, mediated by 6,6´dithionicotinamide, thiol groups were modified by disulfide bonds formation. Mucoadhesion studies were performed on buccal mucosa. In addition, water-uptake capacity, disintegration, release and cytotoxicity studies were completed. Results: The obtained chitosan–thiobutylamidine conjugate displayed 647.4 ± 85.23 µmol/g immobilized thiol groups. Due to the preactivation, approximately 60% of thiol groups were modified by formation of disulfide bonds. Chitosan–thiobutylamidine–mercaptonicotinamide displayed 1.8-fold higher stability and 1.6-fold higher mucoadhesive properties, respectively. The release study demonstrated a 1.4-fold more prolonged drug release compared with corresponding thiomers. Conclusion: According to these results, preactivated thiomers demonstrate an improved stability and increased mucoadhesive properties. Therefore, they seem to be advantageous for buccal administration over corresponding thiomers and chitosan.

Within this study, HEC-cysteamine nanoparticles with free thiol groups in the range of 117–1548 μmol/g were designed and characterized. Nanoparticles were generated via ionic gelation of the cationic polymer with tripolyphosphate (TPP) followed by covalent crosslinking via disulfide bond formation using H2O2 as oxidant. The mean diameter of the particles was in the range of 270–360 nm, and zeta potential was determined to be +4 to +10 mV. Nanoparticles were evaluated in terms of mucoadhesive, permeation enhancing, and biocompatible properties as well as biodegradability. The particles remained attached to porcine intestinal mucosa up to 70% after 3 h of incubation. The more nanoparticles were oxidized; however, the less were their mucoadhesive properties. Nanoparticles applied in a concentration of 0.5% (m/v) with the highest content of free thiol groups improved the transport of fluorescein isothiocyanate dextran 4 (FD4) across Caco-2 cell monolayer 3.94-fold in comparison with control (buffer). In addition, the transport of FD4 was even 1.84-fold enhanced in the presence of 0.5% (m/v) nanoparticles with the lowest free thiol group content. The higher the disulfide bond content within nanoparticles was, to a lower degree nanoparticles were hydrolyzed by cellulase. None of these nanoparticles showed pronounced cytotoxicity. Accordingly, HEC-cysteamine could be a promising excipient for nanoparticulate delivery systems for poorly absorbed drugs.

This study was aimed to synthesize polymeric excipients with improved mucoadhesive, cohesive and in situ-gelling properties to assure a prolonged retention time of dosage forms at a given target site, thereby achieving an increased uptake and improved oral bioavailability of certain challenging therapeutic agents such as peptides and proteins. Accordingly, poly(acrylic acid)-cysteine-2-mercaptonicotinic acid (PAA-cys-2MNA) conjugates were synthesized by the oxidative S–S coupling of PAA-cys (100-, 250- and 450 kDa) with 2-mercaptonicotinic acid (2MNA). Unmodified PAAs, PAAs-cys (thiomers) and PAA-cys-2MNA (100-, 250- and 450 kDa) conjugates were compressed into tablets to perform disintegration tests, mucoadhesion studies and rheological measurements. Moreover, cytotoxicty of the polymers was determined using Caco-2 cells. The resulting PAA-cys-2MNA (100-, 250- and 450 kDa) conjugates displayed 113.5 ± 12.7, 122.7 ± 12.2 and 117.3 ± 4.6 μmol/g of 2-mercaptonicotinic acid, respectively. Due to the immobilization of 2MNA, the PAA-cys-2MNA (pre-activated thiomers) conjugates exhibit comparatively higher swelling properties and disintegration time to the corresponding unmodified and thiolated polymers. On the rotating cylinder, tablets based on PAA-cys-2MNA (100-, 250- and 450 kDa) conjugates displayed 5.0-, 5.4- and 960-fold improved mucoadhesion time in comparison to the corresponding unmodified PAAs. Results achieved from tensile studies were found in good agreement with the results obtained by rotating cylinder method. The apparent viscosity of PAA-cys-2MNA (100-, 250- and 450 kDa) conjugates was improved 1.6-, 2.5- and 206.2-fold, respectively, in comparison to the corresponding unmodified PAAs. Moreover, pre-activated thiomers/mucin mixtures showed a time dependent increase in viscosity up to 24 h, leading to 7.0-, 18.9- and 2678-fold increased viscosity in comparison to unmodified PAAs (100-, 250- and 450 kDa), respectively. All polymers were found non-toxic over Caco-2 cells. Thus, on the basis of achieved results the pre-activated thiomers seem to represent a promising generation of mucoadhesive polymers which are safe to use for prolonged residence time of drug delivery systems to target various mucosa.

The purpose of this study was to design and characterize a novel cationic thiolated polymer. In this regard a hydroxyethylcellulose-cysteamine conjugate (HEC-cysteamine) was synthesized. Oxidative ring opening with periodate and reductive amination with cysteamine were performed in order to immobilize free thiol groups to HEC. The resulting HEC-cysteamine displayed 2035 ± 162 μmol immobilized free thiol groups and 185 ± 64 μmol disulfide bonds per gram of polymer being soluble in both acidic and basic conditions. Unlike the unmodified HEC, in case of HEC-cysteamine, a three-fold increase in the viscosity was observed when equal volumes of the polymer were mixed with mucin solution. Tablets based on HEC-cysteamine remained attached on freshly excised porcine mucosa for 80 h and displayed increased disintegration time of 2 h. Swelling behavior of HEC-cysteamine tablets in 0.1 M phosphate buffer pH 6.8 indicated swelling ratio of 19 within 8 h. In contrast, tablets comprising unmodified HEC detached from the mucosa within few seconds and immediately disintegrated. In addition, they did not exhibit swelling behavior. The transport of rhodamine 123 across freshly excised rat intestine enhanced by a value of approximately 1.6-fold (p-value = 0.0024) in the presence of 0.5% (m/v) HEC-cysteamine as compared to buffer control. Result from cytotoxicity test of HEC-cysteamine applied to Caco-2 cells in concentration of 0.5% (m/v) revealed 82.4 ± 4.60% cell viability. According to these results, HEC-cysteamine seems to be a promising polymer for various pharmaceutical applications especially for intestinal drug delivery.

The aim of this study was to investigate the potential of poly(acrylic acid)–cysteine (PAA–cys) solution and microparticles to enhance the transport of vitamin B12 (VB 12) across Caco-2 cell monolayer and rat intestinal mucosa. Thiolated PAA was synthesized by covalent attachment of l -cysteine. Microparticles were prepared by spray-drying and characterized regarding their size, morphology, thiol group content, VB 12 payload and release, swelling behavior, mucoadhesion, permeation-enhancing effect, and cytotoxicity. Particles with a mean diameter of 2.452 ± 2.26 μm, a payload of 1.11 ± 0.72%, and 190.2 ± 8.85 μmol of free thiol groups per gram were prepared. Swelling behavior studies revealed that the stability of thiolated particles was improved compared with unmodified ones. Of the total VB 12 loaded, 95 ± 0.12% was released within 3 h from thiolated particles. PAA–cys particles exhibited 2.24-fold higher mucoadhesive properties compared with unmodified particles. Permeation experiments with Caco-2 cells proved that permeability of VB 12 with PAA–cys solution and particles was 3.8- and 3.6-fold higher than control, respectively, and with rat intestinal mucosa it was 4.8- and 4.4-fold higher than control, respectively. Negligible cytotoxicity was assessed. PAA–cys is a promising excipient for oral delivery of VB 12 as a solution and as microparticles.

The aim of the present study was to develop an oral delivery system for the peptide drug leuprolide. Gel formulations based on unmodified chitosan/reduced glutathione (GSH) and chitosan-thioglycolic acid (chitosan-TGA)/GSH were prepared, and their effect on the absorption of leuprolide was evaluated in vitro and in vivo in male Sprague Dawley rats. Transport studies were performed with freshly excised rat intestinal mucosa mounted in Ussing-type chambers. Due to the addition of gel formulations comprising 0.5% (m/v) unmodified chitosan/0.5% (m/v) GSH and 0.5% (m/v) chitosan-TGA/0.5% (m/v) GSH, the transport of leuprolide across excised mucosa was improved up to 2.06-fold and 3.79-fold, respectively, in comparison with leuprolide applied in buffer (P(app)=2.87 ± 0.77 × 10⁻⁶ cm/s). In vivo, the addition of oral gel formulation comprising 8 mg of unmodified chitosan, 1mg of GSH and 1mg of leuprolide increased the area under the plasma concentration-time curve (AUC₀₋₈) of leuprolide 1.39-fold in comparison with leuprolide having been administered just in saline. Moreover, the administration of oral gel formulation comprising 8 mg of chitosan-TGA, 1mg of GSH and 1mg of leuprolide resulted in a further enhanced leuprolide plasma concentration, and the area under the plasma concentration-time curve (AUC₀₋₈) of leuprolide was increased 3.72-fold in comparison with the control. With the oral gel formulation comprising 8 mg of chitosan-TGA, a relative bioavailability (versus s.c. injection) of 4.5% was achieved in contrast to the control displaying a relative bioavailability of 1.2%. Thus, according to the achieved results, it is suggested that chitosan-TGA in combination with GSH is a valuable tool for improving the oral bioavailability of the peptide drug leuprolide.

The aim of this study was to examine the potential of self-nanoemulsifying drug delivery systems (SNEDDS) on the uptake of the lipophilic and poorly water soluble phenothiazines thioridazine and chlorpromazine with the isolated plasma derived chylomicron (CM) ex vivo model. The multi-component delivery systems were optimized by evaluating their ability to self-emulsify when introduced to an aqueous medium under gentle agitation. The uptake of phenothiazines by isolated plasma derived chylomicrons was investigated with short chain triglyceride (SCT) SNEDDS, medium chain triglyceride (MCT) SNEDDS, and long chain triglyceride (LCT) SNEDDS. SNEDDS were also evaluated for their stabilities, dispersibilities, percentage transmittances and by particle size analyses. For thioridazine a 5.6-fold and for chlorpromazine a 3.7-fold higher CM uptake could be observed using a LCT-SNEDDS formulation compared to the drugs without formulation. In contrast, ex vivo uptake by isolated CM was not significantly increased by SNEDDS formulations based on MCT and SCT. Compared with isolated CM, the CM sizes were increased 2.5-fold in LCT-SNEDDS, whereas in MCT-SNEDDS or SCT-SNEDDS only a small, non-significant (P0.05) increase in CM size was observed. These results show that distinct SNEDDS formulations containing phenothiazines are efficiently uptaken by plasma derived chylomicrons ex vivo.

Purpose: To prepare, using non-solvent addition technique, diclofenac sodium-ethylcellulose microparticles with modified drug release properties.Methods: Microparticles were prepared by non-solvent addition phase separation method and characterized by micromeritics, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), dissolution test and thermal analysis.Results: The microparticles were whitish, irregular, aggregated, and in the size range of 390 - 442 μm size. Drug embedment efficiency was 89 - 91 %. Characterisation studies indicate that there was no strong chemical interaction between the drug and the polymer in the microparticles. Polymer concentration and sustained release behavior were directly proportional.Conclusion: Non-solvent addition phase separation is a suitable method for preparing diclofenac sodium-ethylcellulose multi-unit controlled release drug delivery system.Keywords: Phase separation, Diclofenac sodium, Ethylcellulose, Non-solvent addition, Characterisation.