Self-nanoemulsifying formulation for oral delivery of sildenafil: effect on physicochemical attributes and in vivo pharmacokinetics.

Sildenafil (SLD) is employed for the management of erectile dysfunction and pulmonary arterial hypertension. It exhibits meagre water solubility and is available in the form of citrate salt hydrate to improve the solubility. However, it still exhibits moderate solubility, high first-pass metabolism, resulting in very less oral bioavailability. The present study demonstrates the preparation of self-nanoemulsifying drug delivery system for augmenting the oral bioavailability of SLD. Oleic acid and Capmul MCM C8 blend (oil phase), Cremophor® RH40 (surfactant), and Labrafil® M1944 CS (cosurfactant) were selected as main constituents for making liquid preconcentrate based on the solubility and emulsification study. The preconcentrate upon dilution and emulsification showed droplet size 52.03 ± 13.03 nm, PDI 0.143 ± 0.028, and % transmittance was 99.77 ± 1.86% with SLD load of 40 mg/g of formulation. The prepared formulation was further assessed for stability, in vitro release, Caco-2 cell uptake, and in vivo pharmacokinetic performance. SLD-SNEDDS formulation was found to be robust in terms of stability against several folds dilution in the gastrointestinal tract (GIT), freeze-thaw cycles, and had a storage stability of 3 months at 4 °C and 25 °C. SLD-SNEDDS showed ~4.7-fold and ~5-fold increase in time- and concentration-dependent cellular uptake as against SLD cultured with Caco-2 cells. In vivo pharmacokinetic study revealed ~5.8- and ~2.5-fold increase in AUC0-∞ values in case of SLD-SNEDDS as against SLD suspension and SLD citrate solution, respectively.

Lipid- and TPGS-Based Core-Shell-Type Nanocapsules Endowed with High Paclitaxel Loading and Enhanced Anticancer Potential.

The current study elucidates the improved drug loading of paclitaxel (PTX) in lipid- and D-α-tocopheryl polyethylene glycol succinate (TPGS)-based core-shell-type lipid nanocapsules (PTX-TPGS-LNC) for augmenting the therapeutic efficacy and curbing the toxicity. PTX-TPGS-LNCs were formulated by employing anti-solvent precipitation technique and displayed a particle size of 162.1 ± 4.70 nm and % practical drug loading of 15.04 ± 2.44%. Electron microscopy revealed that PTX-TPGS-LNCs have spherical morphology and the inner core was surrounded by a relatively lighter region, i.e., layer of lipids and TPGS. The nature of loaded PTX inside the PTX-TPGS-LNC was also confirmed using DSC and PXRD analysis. The in vitro release study showed biphasic and sustained release pattern of PTX from PTX-TPGS-LNC and it showed ~ threefold higher PTX uptake in MCF-7 cell line in comparison to free PTX. Moreover, it was apparent from the cytotoxicity assay that PTX-TPGS-LNC displayed higher cytotoxicity in MCF-7 cells and revealed ~ 2.92-fold decrease in IC50 value as against free PTX when incubated for 72 h. The apoptotic index in case of PTX-TPGS-LNC was ~ twofold higher than free PTX. The pharmacokinetic profile of PTX-TPGS-LNC revealed a ~ 3.18-fold increase in t1/2 and a ~ 2.62-fold higher AUC(0→∞) compared to Intaxel®. Finally, treatment with PTX-TPGS-LNC demonstrated significant lowering in the % tumor burden and serum toxicity markers compared to marketed formulation Intaxel®. Thus, the lipid- and TPGS-based core-shell-type LNC with high PTX loading can advance the existing standards of therapy for overshadowing cancer.

Enhanced stability and oral bioavailability of erlotinib by solid self nano emulsifying drug delivery systems.

The present investigation demonstrates the preparation of solid self nanoemulsfying drug delivery system (sSNEDDS) to enhance stability and bioavailability of Erlotinib (ERL) via the oral route. Capmul®MCM EP (CPM EP, oil), Cremophor® RH 40 (CMR RH 40, surfactant), and LBF CS (LBF CS, cosurfactant) were chosen as chief components for preparing Liquids SNEDDS (L-ERL-SNEDDS) based on solubility and emulsion forming ability. Pseudo ternary phase diagram and constrained mixture designs were applied to identify the self-emulsifying area and it was found that CPM EP, CMR RH 40, and LBF CS in the ratio of 59:11:30 showed optimized particle size (110.08 nm), with narrow PDI (0.114) and high ERL loading capacity (14.31 mg/g). Adsorption method was implemented for solidification of L-ERL-SNEDDS. Among various solid carriers were studied, Aerosil® 200 (A200) was finalized based on free flowing property and reconstitution ability. DSC and XRD studies revealed that crystallinity of drug was reduced in developed system. The developed formulation (named as, A200-ERL-sSNEDDS) showed increased cytotoxicity and apoptosis in PANC-1 and MIA PaCa-2 cells. Pharmacokinetic studies revealed ∼2.2 times increase in AUC0-∞values in case of A200-ERL-sSNEDDS as compared to free ERL. Thus current strategy can be extrapolated for delivering of poorly soluble drugs via oral route.

Partial inclusion complex assisted crosslinked ß-cyclodextrin nanoparticles for improving therapeutic potential of docetaxel against breast cancer.

The present investigation demonstrates the development of crosslinked ß-cyclodextrin nanoparticles (ß-CD NPs) for enhancing the therapeutic efficacy of docetaxel (DTX) against breast cancer. Initially, a partial inclusion complex between ß-CD and polypropylene glycol (PPG) was formed to induce self-assembly. This was followed by crosslinking of ß-CDs using epichlorohydrin (EPI) and removal (by solubilization) of PPG to yield uniform ß-CD NPs. The formed particles were used for loading DTX to form DTX ß-CD NPs. The resultant DTX ß-CD NPs exhibited particle size of 223.36 ± 17.73 nm with polydispersity index (PDI) of 0.13 ± 0.09 and showed entrapment efficiency of 54.53 ± 2%. Increased cell uptake (~5-fold), cytotoxicity (~3.3-fold), and apoptosis were observed in MDA-MB-231 cells when treated with DTX ß-CD NPs in comparison to free DTX. Moreover, pharmacokinetic evaluation of DTX ß-CD NPs revealed ~2 and ~5-fold increase in AUC0-∞ and mean residence time (MRT) of DTX when compared to Docepar®. Further, the anti-tumor activity using DMBA-induced cancer model showed that DTX ß-CD NPs were capable of reducing the tumor volume to ~40%, whereas Docepar® was able to reduce tumor volume till ~80%. Finally, the toxicity evaluation of DTX ß-CD NPs revealed no short-term nephrotoxicity and was confirmed by estimating the levels of biomarkers and histopathology of the organs. Thus, the proposed formulation strategy can yield uniformly formed ß-CD NPs which can be effectively utilized for improving the therapeutic efficacy of DTX.

pH sensitive liposomes assisted specific and improved breast cancer therapy using co-delivery of SIRT1 shRNA and Docetaxel.

Combining the bio-therapeutics with chemotherapeutic drugs can assist in augmenting the therapeutic standards by increasing the efficacy and decreasing the toxicity. Hence, in the present investigation Docetaxel (DTX) loaded pH-sensitive SIRT1 shRNA complexed lipoplex (DTX-lipoplex) were developed and explored for their improved breast cancer potential. The DTX-lipoplex were prepared by solvent evaporation and rehydration method and were evaluated for various quality attributes (particle size, % entrapment efficiency, hemotoxicity, DNA stability efficiency etc.), in vitro drug release, cell culture assays, antitumor efficacy and in vivo toxicity. The DTX-lipoplex exhibited a size of ~200 nm and zeta-potential of ~20 mV with ~70% encapsulation. Through systematic in vitro and in vivo examinations, DTX-lipoplex showed ~3 fold higher DTX titre within the tumor cells thereby significantly reducing the tumor burden (~78%) when compared to the marketed non pH sensitive lipid transfection agent and clinical counterpart i.e. Taxotere®. Thus, to conclude it can be said that co-delivering DTX and SIRT1 shRNA in a single tumor-specific nano-platform can improve the therapeutic potential of current therapy.

Tumor microenvironment responsive VEGF-antibody functionalized pH sensitive liposomes of docetaxel for augmented breast cancer therapy.

The present work exploits the tumor microenvironment which differs significantly from normal cellular environment in terms of both, having lower extracellular pH and increased angiogenesis capacity. To reduce systemic toxicity of docetaxel (DTX) and increase its therapeutic potential, VEGF antibody functionalized PEGylated pH sensitive liposomes (VEGF-PEG-pH-Lipo-DTX) were developed. The liposomes prepared by thin film hydration technique were later conjugated with VEGF antibody on liposomal surface by standard carbodiimide chemistry and using DSPE-PEG-COOH as linker. The VEGF-PEG-pH-Lipo-DTX displayed particle size of ~206 nm with an entrapment efficiency of ~62%. The transmission electron microscopy images revealed spherical shape of liposomes and corroborated the particle size obtained from zetasizer. The in vitro release study revealed biphasic release pattern of DTX from VEGF-PEG-pH-Lipo-DTX. The % drug released was also significantly higher at pH 5.5 which guarantees rapid endosomal escape and faster intracellular drug release. In case of VEGF-PEG-pH-Lipo-DTX the cellular uptake in MCF-7 cell line was augmented ~3.17-fold as compared to free DTX probably due to the VEGF-positive nature of MCF-7 cell (increased affinity for VEGF). Further, it was evident from the cytotoxicity assay that VEGF-PEG-pH-Lipo-DTX showed higher cytotoxicity in MCF-7 cells and ~5.78-fold reduction in IC50 value as compared to free DTX. The apoptotic index observed in case of VEGF-PEG-pH-Lipo-DTX was ~1.70-fold higher than free DTX. The VEGF-PEG-pH-Lipo-DTX inhibited the proliferation of HUVECs stimulated by VEGF, warranting its anti-angiogenic potential. Furthermore, pharmacokinetic profile of VEGF-PEG-pH-Lipo-DTX revealed a ~2.94-fold increase in t1/2 and a ~1.25-fold higher AUC (0→∞) as compared to marketed formulation Taxotere®. Similarly, mean residence time was also increased ~2.50-fold as compared to Taxotere®. Finally, treatment with VEGF-PEG-pH-Lipo-DTX demonstrated significant reduction in % tumor burden (~35%) as compared to Taxotere® (~75%). Thus, the combined approach of using PEGylated pH sensitive liposomes along with VEGF antibody functionalization for efficient targeting can improve current standards of DTX therapy for treatment of breast cancer.

Exploring protein stabilized multiple emulsion with permeation enhancer for oral delivery of insulin.

In present study, we have developed W/O/W microemulsion (ME) containing piperine (PiP) as a permeation enhancer and albumin (Alb) serving as a stabilizer for oral delivery of insulin (INS). The resultant formulation, ME(INS)-PiP-Alb exhibited droplet size of 3.35 ± 0.25 µm along with polydispersity index (PDI) of 0.30 ± 0.10. The formulation process employed for developing ME(INS)-PiP-Alb showed no effect on INS's chemical and conformational stability. Further, ME(INS)-PiP-Alb was able to maintain desired attributes (size & PDI) along with INS stability in simulated gastrointestinal fluids. Also, ME(INS)-PiP-Alb rendered higher protection to INS in presence of pepsin and trypsin than ME(INS)-PiP. In qualitative Caco-2 cell uptake, INS loaded ME's showed higher uptake in comparison to free INS. Whereas, in permeability studies ME(INS)-PiP-Alb showed ~4 and ~1.5-fold enhanced permeation than free INS and ME(INS) without PiP groups respectively. Also, in ex vivo intestinal permeation studies similar fold increment in permeation were observed. Interestingly, the pharmacodynamic studies revealed ~3.2-fold higher hypoglycemic effect in animals treated with ME(INS)-PiP-Alb in comparison to ME(INS)-PiP. Similarly, the pharmacokinetic studies also revealed ~1.6 fold higher AUC for ME(INS)-PiP-Alb than ME(INS)-PiP. Thus, in vivo results suggested that Alb as a stabilizer can assist in improving the hypoglycemic effect of the developed ME with PiP. Hence, this strategy can also be extrapolated for delivering other bio-macromolecules orally.

Lipid and Biosurfactant Based Core-Shell-Type Nanocapsules Having High Drug Loading of Paclitaxel for Improved Breast Cancer Therapy.

The current investigation illustrates high drug loading of Paclitaxel (PTX) in lipid- and biosurfactant-based core-shell-type nanocapsules for improving therapeutic potential and reducing toxicity of PTX. The nanocapsules were prepared using the antisolvent precipitation technique having a particle size of 253.8 ± 15.4 nm and drug loading of ∼19%. The microscopic evaluation revealed the spherical shape of the nanocapsules and corroborated with the particle size obtained from Zetasizer. It also revealed the drug core enveloped by the relatively lighter shadowed region, that is, the layer of lipids and the biosurfactant. The in vitro release study showed biphasic and sustained release pattern of PTX from core-shell-type nanocapsules. In case of nanocapsules, the cellular uptake in the MCF-7 cell line was augmented ∼3.17-fold as compared to free PTX. Further, it was evident from the cytotoxicity assay that nanocapsules displayed greater cytotoxicity in MCF-7 cells and ∼2.98-fold decrease in the IC50 value as compared to free PTX. The apoptotic index observed in case of nanocapsules was ∼2.04-fold higher than that of free PTX. Furthermore, the pharmacokinetic profile of nanocapsules revealed a ∼7.21-fold increase in t1/2 and a ∼3.27-fold higher AUC(0→∞) compared to Intaxel. Finally, treatment with PTX core-shell-type nanocapsules demonstrated significant cutback in the % tumor burden and serum toxicity markers compared to marketed formulation. Thus, the current approach of core-shell-type nanocapsules with high drug loading can improve the current standards of PTX therapy for treatment of cancer.

Exploring the potential of novel pH sensitive lipoplexes for tumor targeted gene delivery with reduced toxicity.

The present investigation explores the potential of pH sensitive cationic liposomes for its in vivo tumor targeted gene transfection in comparison to its marketed transfecting reagent Lipofectamine® 2000. The lipoplexes were prepared by varying the molar mass ratio of cationic pH-sensitive liposomes with respect to pDNA and were evaluated for optimum size, zeta potential and for complete gel retardation. Similarly, the stability of lipoplexes in the presence of DNase I and serum was evaluated by using gel retardation and heparin displacement assay. The in vitro hemocompatibility assessment of pDNA lipoplexes revealed < 8.5% of hemolysis which was lower than the hemolysis observed for Lipofectamine® lipoplexes (15.9%). The internalization and pH dependent uptake inhibition using ammonium chloride in MCF-7 cells revealed higher internalization and pH sensitive nature of the prepared pH-sensitive system. The pDNA lipoplexes displayed > 80% of cell viability along with 4.42, 5.18 and 5.00 fold higher transfection efficiency than Lipofectamine® lipoplexes in MCF-7, HeLa and HEK-293 cells respectively. Also the in vivo toxicity assessment exhibited no significant change in the levels of biomarkers and no histopathological deformations in case of pDNA lipoplexes treated animals in comparison to control group (PBS). Further, pDNA lipoplexes demonstrated ~1.3 fold higher tumor transfection over Lipofectamine® lipoplexes indicating superior in vivo gene deliverable capabilities. Thus, the developed pH sensitive lipoplexes promises to be a potential tumor targeting and safe delivery system than Lipofectamine® 2000.

Mechanistic insights into high permeation vesicle-mediated synergistic enhancement of transdermal drug permeation.

Aim: To design a nanocarrier platform for enhanced transdermal drug permeation. Materials & methods: Gel-based high permeation vesicles (HPVs) were developed and their performance in terms of transdermal flux improvement, in vitro release and skin irritancy was assessed. The mechanistic insights of permeation enhancement were explored using confocal laser scanning microscopy, ATR-FTIR, DSC and P31 NMR. Results: HPVs exhibited as vesicles with uniform size (∼150 nm), extended drug-release profile (∼48 h) and improved transdermal flux. HPVs were also nontoxic and nonirritant to skin. Enhanced vesicle deformability, improved vesicle membrane fluidity and synergistic permeation enhancement action of synergistic combination of permeation enhancer components was found to be responsible for HPV-mediated permeation enhancement. Conclusion: Overall, the study established that HPVs demonstrate a promising therapeutic advantage over conventional transdermal drug carriers.

Design and Toxicity Evaluation of Novel Fatty Acid-Amino Acid-Based Biocompatible Surfactants.

Surfactants occupy an important place owing to their wide application, but primarily compromised due to its toxicity issues. This raises the need for exploration of newer surfactants with increased biocompatibility. Novel fatty acid- and amino acid-based surfactants were prepared using standard carbodiimide chemistry. Pyrene assay was implemented to confirm the amphiphilic nature of the surfactants and to calculate their CMC (critical micellar concentration). In vitro hemolytic and cell culture study in MCF-7 and HEK cell line were done to check the in vitro biocompatibility of the developed surfactants in comparison to marketed surfactants Triton X-100 and Tween ® 80. In vivo biocompatibility test in female Swiss albino mice was carried out in comparison to marketed surfactants with respect to serum markers, organ histology, and RBC morphology. Surfactant synthesis provided more than 60% yield in all the conjugates. Pyrene assay concluded the amphiphilic nature of the surfactants with lowest CMC of 0.083% w/v in the case of stearic acid and valine conjugate. In vitro hemolytic and cell culture study depicted highest biocompatibility in vitro as compared to marketed surfactants. Similar results were obtained in in vivo biocompatibility with respect to AST (aspartate transaminase), ALT (alanine transaminase), BUN (blood urea nitrogen), and creatinine serum levels and histology of spleen, liver, and kidney in comparison to marketed surfactants Triton X-100 and Tween ® 80. The developed surfactant also depicted least RBC morphology changes in vivo. Stearic acid valine conjugate thus depicted potential for further application in formulation development replacing the commercially available surfactants.

Tocophersolan stabilized lipid nanocapsules with high drug loading to improve the permeability and oral bioavailability of curcumin.

The present investigation highlights the development of D-α-Tocopheryl polyethylene glycol 1000 succinate (Tocophersolan; TPGS) stabilized lipid nanocapsules for enhancing the oral bioavailability and permeability of curcumin (CUR). Lipid nanocapsules were optimized for different lipids, different concentrations of TPGS and different drug: lipid ratio and were further lyophilized. Subsequently, they were characterized by powder X-ray diffraction, Transmission electron microscopy and also evaluated for in vitro release study, Caco-2 cell uptake study, ex vivo intestinal permeability and in vivo pharmacokinetic performance. Optimized lipid nanocapsules exhibited desirable quality attributes (average particle size of 190 nm, polydispersity index of 0.240 and average % entrapment efficiency of 51.06 ±â€¯7.27) employing Maisine™ 35-1 as a lipid carrier, 0.05% TPGS and CUR: lipid ratio of 5:10 and showed sustained release biphasic pattern. They showcased excellent stability in simulated gastrointestinal fluids and storage stability. The CUR nanocapsules exhibited ∼14-fold higher Caco-2 cell uptake and ∼12.8-fold increased ex vivo intestinal permeability. Also, the AUC of CUR nanocapsules in Sprague Dawley rats was increased by ∼12 folds and MRT ∼2.47-folds as compared to aqueous CUR suspension. Thus, lipid nanocapsules possessed a positive impact on improving the permeability and oral bioavailability of CUR.

Lipid and TPGS based novel core-shell type nanocapsular sustained release system of methotrexate for intravenous application.

Core shell nanocapsules present an interesting system for attaining high loading of drug. In an attempt, lipid and TPGS based novel core-shell nanocapsule were prepared to achieve high drug loading with sustained release of model hydrophilic drug methotrexate (MTX). Antisolvent nanoprecipitation was utilized for the formulation of nanoparticles. Optimized formulation depicted 223.6 ± 24.1 nm particle size, 0.243 ± 0.034 PDI, zeta potential -2.07 ± 0.51 mV and 15.03 ± 1.92%drug loading. In vitro release showed biphasic release for 12 h with initial burst phase followed by sustained release phase. Haemolytic study on RBCs revealed haemocompatible nature of MTX-TPGS nanoparticles compared to Biotrexate® (Zydus). In vitro cell culture studies depicted 3 folds and 2.66 folds increase in cellular uptake of MTX at 10 µg/ml and 15 µg/ml respectively for developed nanoparticles with 3.81 folds decrease in IC50 value as compared to Biotrexate®. Higher apoptosis and increased lysosomal membrane permeability were also depicted by MTX-TPGS nanoparticles. 2.45 folds increase in AUC and 3.68 folds increase in T1/2 was achieved in pharmacokinetic study. Significant reduction in tumor burden and serum biochemical parameters depicted efficacy and safety respectively of the formulation as compared to Biotrexate®. RBCs morphology was retained after MTX-TPGS exposure proving its haemocompatibility in vivo.

Novel biosurfactant and lipid core-shell type nanocapsular sustained release system for intravenous application of methotrexate.

In an attempt to prepare novel core shell nanocapsules, lipid and Stearic acid-Valine conjugate (Biosurfactant) based nanosystem was prepared to attain high drug loading of hydrophilic drug methotrexate (MTX), with sustained release. Antisolvent nanoprecipitation technique was employed for the formulation of nanoparticles (NPs). Optimized formulation depicted 209.6 ±â€¯31.3 nm particle size, 0.209 ±â€¯0.072 PDI and 14.98 ±â€¯1.33 %w/w drug loading. In vitro release depicted biphasic release for 12 h with initial burst phase followed by sustained release phase. In vitro Haemolytic study on RBCs revealed haemocompatible nature of MTX-Biosurfactant NPs compared to Biotrexate® (Zydus). In vitro cell culture studies showed 3.33 folds and 3.50 folds increase in cellular uptake of MTX at 10 µg/ml and 15 µg/ml concentration respectively for developed nanoparticles with 4.16 folds decrease in IC50 value. Higher apoptosis and increased lysosomal membrane permeability were obtained in MTX-Biosurfactants NPs. AUC and T1/2 was found to increase by 2.55 and 3.25 folds respectively in pharmacokinetic study. Significant reduction in tumor burden and serum toxicity marker level depicted efficacy and safety respectively of the formulation as compared to Biotrexate®. RBCs morphology was retained after MTX-Biosurfactants NPs exposure proving its haemocompatibility in vivo.

Exploring an interesting dual functionality of anacardic acid for efficient paclitaxel delivery in breast cancer therapy.

AIM: To explore the potential of paclitaxel (PTX)-loaded anacardic acid conjugated hydrophobized gelatin nanoparticles. MATERIALS & METHODS: Nanoparticles prepared by nanoprecipitation technique were evaluated for various quality attributes (particle size, % entrapment efficiency) in vitro drug release, MCF-7 cell uptake, cell cytotoxicity, in vivo pharmacokinetics, antitumor efficacy and toxicity. RESULTS: The nanoparticles (250-300 nm, 74% entrapment efficiency) showed approximately 2.26-fold higher apoptosis index and approximately 5.86-fold reduction in IC50 value compared with PTX in MCF-7 cells. Also, approximately 3.51- and 1.36-fold increase in area under the curve compared with Intaxel® and Nanoxel™ (both from Fresenius Kabi, Gurugram, India) was achieved. Significant tumor burden reduction (∼60%) and reduced toxicity was observed compared with marketed formulations. CONCLUSION: The hydrophobized gelatin nanoparticles displayed promising therapeutic potential, paving a new path for efficient PTX delivery.

Chemosensitizer and docetaxel-loaded albumin nanoparticle: overcoming drug resistance and improving therapeutic efficacy.

AIM: Investigated strategy exploits the utilization of quercetin as a chemosensitizer for docetaxel (DTX), which was incorporated into albumin nanoparticles (NPs; bovine serum albumin NPs [BSA-NPs]). MATERIAL & METHODS: BSA-NPs containing both drugs were optimized, extensively characterized for different quality attributes and performance was investigated using series of in vitro and in vivo investigations. RESULTS: Co-encapsulated BSA-NPs exhibited size: 209.26 ± 9.84 nm, polydispersibility index: 0.184 ± 0.05 and good entrapment efficiency (∼75% for DTX and ∼68% for quercetin). Higher in vitro cytotoxicity, cell uptake and apoptosis were achieved in MCF-7 cell line. Similarly, higher P-glycoprotein efflux inhibition was observed in MDA-MB-231. About 2.5-fold increase in bioavailability of DTX was achieved with improved antitumor efficacy and reduced in vivo toxicity. CONCLUSION: Developed BSA-NPs provide an effective and safer alternative approach using co-delivery of chemosensitizer.

Active natural oil-based nanoemulsion containing tacrolimus for synergistic antipsoriatic efficacy.

AIM: The current study is emphasized on development of a nanoemulsion system that simultaneously delivers two antipsoriatic agents viz. Tacrolimus and Kalonji oil (functional excepient) topically. MATERIALS & METHODS: A nanoemulsion was characterized for quality attributes; a nanoemulsion gel was evaluated for spreadability, viscosity, dermal bioavailability, and in vitro efficacy in A-431 cell line, and so forth. In vivo performance was evaluated on psoriasis model in BALB/c mice. RESULTS: Nanoemulsion depicted droplet size: 93.37 ± 2.58 nm with PDI (Polydispersity Index) 0.330 ± 0.025. The nanoemulsion gel exhibited desirable spreadability with sustained release pattern (biphasic). Dermal bioavailability enhancement (4.33-fold) accompanied significant in vitro results. A significant reduction in serum cytokines and improvement in psoriatic condition was achieved in vivo, indicating formulation efficacy compared with marketed formulation (Tacroz Forte, Glenmark Pharmaceuticals Ltd, Maharashtra, India). CONCLUSION: Nanoemulsion gel thus provides an effective alternative for psoriasis treatment.

Implication of linker length on cell cytotoxicity, pharmacokinetic and toxicity profile of gemcitabine-docetaxel combinatorial dual drug conjugate.

The present study investigates effect of linkers [zero length (without linker), short length linker (glycine and lysine) and long length linker (PEG1000, PEG2000 and PEG3500)] on pharmacokinetics and toxicity of docetaxel (DTX) and gemcitabine (GEM) bio-conjugates. Conjugates were synthesized via carbodiimide chemistry and characterized by 1H NMR and FTIR. Conjugation of DTX and GEM via linkers showed diverse physiochemical and plasma stability profile. Cellular uptake mechanism in MCF-7 and MDA-MB-231 cell lines revealed clathrin mediated internalization of bio-conjugates developed by using long length linkers, leading to higher cytotoxicity compared with free drug congeners. DTX-PEG3500-GEM and DTX-PEG2000-GEM demonstrated 4.21 and 3.81-fold higher AUC(0-∞) of GEM in comparison with GEM alone. DTX-PEG2000-GEM and DTX-PEG3500-GEM exhibited reduced hepato-, nephro- and haemolytic toxicity as evident via histopathology, biochemical markers and SEM analysis of RBCs. Conclusively, PEG2000 and PEG3500 significantly improved pharmacokinetics without any sign of toxicity and hence can be explored further for the development of dual-drug conjugates for better therapeutic efficacy.