Simvastatin (SVA) is a well-prescribed drug for treating cardiovascular and hypercholesterolemia. Due to the extensive hepatic first-pass metabolism and poor solubility, its oral bioavailability is 5%. Solid lipid nanoparticles (SLNs) and hydrogel-coated SLNs were investigated to overcome the limited bioavailability of SVA. Four different lipids used alone or in combination with two stabilizers were employed to generate 13 SLNs. Two concentrations of chitosan (CS) and alginate (AL) were coating materials. SLNs were studied for particle size, zeta potential, in vitro release, rheology, and bioavailability. The viscosities of both the bare and coated SLNs exhibited shear-thinning behavior. The viscosity of F11 (Chitosan 1%) at 20 and 40 rpm were 424 and 168 cp, respectively. F11 had a particle size of 260.1 ± 3.72 nm with a higher release; the particle size of F11-CS at 1% was 524.3 ± 80.31 nm. In vivo studies illustrated that F11 had the highest plasma concentration when compared with the SVA suspension and coated chitosan (F11 (Chitosan 1%)). Greater bioavailability is measured as (AUC0→24), as compared to uncoated ones. The AUC for F11, F11-CS 1%, and the SVA suspension were 1880.4, 3562.18, and 272 ng·h/mL, respectively. Both bare and coated SLNs exhibited a significantly higher relative bioavailability when compared to that from the control SVA.

Andrographolide (AG) is an antitumor phytochemical that acts against non-Hodgkin\'s lymphoma. However, AG shows low oral bioavailability due to extensive first-pass metabolism and P-glycoprotein efflux. Novel biocompatible lipoprotein-simulating nanosystems, emulsomes (EMLs), have gained significant attention due to their composition of natural components, in addition to being lymphotropic. Loading AG on EMLs is believed to mitigate the disadvantage of AG and enhance its lymphatic transport. This study developed a chylomicron-simulating system (EMLs) as a novel tool to overcome the AG oral delivery obstacles. Optimized EML-AG had a promising vesicular size of 281.62 ± 1.73 nm, a zeta potential of - 22.73 ± 0.06 mV, and a high entrapment efficiency of 96.55% ± 0.25%, which favors lymphatic targeting. In vivo pharmacokinetic studies of EML-AG showed significant enhancement (> sixfold increase) in the rate and extent of AG absorption compared with free AG. However, intraperitoneal injection of a cycloheximide inhibitor caused a significant decrease in AG absorption (~ 52%), confirming the lymphatic targeting potential of EMLs. Therefore, EMLs can be a promising novel nanoplatform for circumventing AG oral delivery obstacles and provide targeted delivery to the lymphatic system at a lower dose with fewer side effects.

Aim: The aim of this study was to elaborate on \'bioemulsomes,\' novel biocompatible lipoprotein analogs for effective lymphatic transport of baicalin (BCL). Methods: BCL bioemulsomes were developed and optimized and in vitro physicochemical characterization performed. The bioavailability of BCL bioemulsomes compared with free BCL was investigated using in vivo pharmacokinetics studies. Finally, BCL lymphatic transport was assessed via cycloheximide blockade assay. Results: Optimized BCL-loaded nanoemulsomes showed promising in vitro characteristics that favor lymphatic targeting. In vivo pharmacokinetics showed a significant improvement in bioavailability over free BCL. A significant decrease in BCL emulsome absorption (33%) was exhibited after chemical blockage of the lymphatic pathway, confirming the lymphatic transport potential. Conclusion: Bioemulsomes could be a promising tool for bypassing BCL oral delivery hurdles as well as lymphatic transport, paving the way for potential treatment of lymphoma.

The present work reports the development, optimization and characterization of novel lipid based nanoformulations viz., Liquid crystalline nanoparticles (LCNP), solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) and liposomes loaded with Tacrolimus (Tac) for topical delivery. Different nanoformulations were developed after screening lipids and suitable surfactants depending upon emulsification ability. The various nanoformulations were then optimized (to achieve higher entrapment efficacy, lower particle size, PDI and zeta potential), characterized and loaded into gel. The gels loaded with nanoformulations were also characterized depending upon rheology and viscosity. The gels were analyzed for in vitro drug release, HaCaT cell lines studies and skin permeation studies. The in vivo efficacy studies were carried out using mouse tail model and skin irritation studies using Draize patch test and measurement of TEWL. The developed nanoformulations showed optimum particle size (<200 nm), polydispersity index (PDI < 0.3), zeta potential (≥-10 mV) and higher entrapment efficiency (>85%). The nanoformulations showed higher penetration of Tac into skin. Tac-LCNP, Tac-SLN, Tac-NLC and Tac-liposomes loaded gels showed 14, 11.5, 12.5 and 3.7 folds increment in dermal bioavailability respectively, in comparison to free Tac loaded gel and 2.5, 2 and ∼2 folds augmentation in dermal bioavailability respectively as compared to Tacroz™ Forte. In case of Tac-liposomes, the dermal bioavailability was lower as compared with the marketed formulation, Tacroz™ Forte. Despite, the increased bioavailability into the skin, the developed nanoformulations showed no significant skin irritation. The above mentioned nanoformulations were able to achieve greater penetration of Tac into the skin as compared to marketed ointment of Tac, Tacroz™ Forte.

In the present investigation, Quality by Design (QbD) approach was applied on the development and optimization of solid lipid nanoparticle (SLN) formulation of hydrophilic drug rivastigmine (RHT). RHT SLN were formulated by homogenization and ultrasonication method using Compritol 888 ATO, tween-80 and poloxamer-188 as lipid, surfactant and stabilizer respectively. The effect of independent variables (X1 - drug: lipid ratio, X2 - surfactant concentration and X3 - homogenization time) on quality attributes of SLN i.e. dependent variables (Y1 - size, Y2 - PDI and Y3 - %entrapment efficiency (%EE)) were investigated using 3(3) factorial design. Multiple linear regression analysis and ANOVA were employed to indentify and estimate the main effect, 2FI, quadratic and cubic effect. Optimized RHT SLN formula was derived from an overlay plot on which further effect of probe sonication was evaluated. Final RHT SLN showed narrow size distribution (PDI- 0.132±0.016) with particle size of 82.5±4.07 nm and %EE of 66.84±2.49. DSC and XRD study showed incorporation of RHT into imperfect crystal lattice of Compritol 888 ATO. In comparison to RHT solution, RHT SLN showed higher in-vitro and ex-vivo diffusion. The diffusion followed Higuchi model indicating drug diffusion from the lipid matrix due to erosion. Histopathology study showed intact nasal mucosa with RHT SLN indicating safety of RHT SLN for intranasal administration.

According to the World Health Organization, 46% of the world\'s children suffer from anemia, which is usually treated with iron supplements such as ferrous sulfate. The aim of this study was to prepare iron as solid lipid nanoparticles, in order to find an innovative way for alleviating the disadvantages associated with commercially available tablets. These limitations include adverse effects on the digestive system resulting in constipation and blood in the stool. The second drawback is the high variability in the absorption of iron and thus in its bioavailability. Iron solid lipid nanoparticles (Fe-SLNs) were prepared by hot homogenization/ultrasonication. Solubility of ferrous sulfate in different solid lipids was measured, and effects of process variables such as the surfactant type and concentration, homogenization and ultrasonication times, and charge-inducing agent on the particle size, zeta potential, and encapsulation efficiency were determined. Furthermore, in vitro drug release and in vivo pharmacokinetics were studied in rabbits. Results indicated that Fe-SLNs consisted of 3% Compritol 888 ATO, 1% Lecithin, 3% Poloxamer 188, and 0.2% dicetylphosphate, with an average particle size of 25 nm with 92.3% entrapment efficiency. In vivo pharmacokinetic study revealed more than fourfold enhanced bioavailability. In conclusion, Fe-SLNs could be a promising carrier for iron with enhanced oral bioavailability.

Metformin hydrochloride (MET) sustained-release solid dispersions (SD) were prepared by the solvent evaporation and closed melt method, using compritol 888 ATO as the polymer with five different drug-carrier ratios. Characterization of solid dispersion was carried out by Fourier Transform Infrared (FTIR) spectroscopy, ultraviolet (UV) spectroscopy, Differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD). The FTIR and UV studies suggested that no bond formation had occurred between the polymer and the drug. DSC and XPRD results ruled out any interaction or complex formation between the drug and the polymer. The formulated SD had acceptable physicochemical characters and SD with a 1 : 4 drug : Polymer ratio, which released the drug over an extended period of eight-to-ten hours. The data obtained from the in vitro release studies were fitted with various kinetic models and were found to follow the Korsmeyer-Peppas equation. The prepared SD showed good stability over the studied time period. The solvent evaporation method was found to be more helpful than the closed melt method, giving the sustained release action. The SD with a 1 : 4 ratio of drug to polymer, by the solvent evaporation method, was selected as the most effective candidate for the subsequent development of a well-timed, sustained-release dosage form of the drug.