In vitro evaluation of tumor targeting ability of a parenteral enoxaparin-coated self-emulsifying drug delivery system

Replacing PEG-surfactants in self-emulsifying drug delivery systems: Surfactants with polyhydroxy head groups for advanced cytosolic drug delivery

AIM

Evaluation of different polyhydroxy surfaces in SEDDS to overcome the limitations associated with conventional polyethylene glycol (PEG)-based SEDDS surfaces for intracellular drug delivery.

METHODS

Anionic, cationic and non-ionic polyglycerol- (PG-) and alkylpolyglucoside- (APG-) surfactant based SEDDS were developed and compared to conventional PEG-SEDDS. Particular emphasis was placed on the impact of SEDDS surface decoration on size and zeta potential, drug loading and protective effect, mucus diffusion, SEDDS-cell interaction and intracellular delivery of the model drug curcumin.

RESULTS

After self-emulsification, SEDDS droplets sizes were within the range of 35-190 nm. SEDDS formulated with high amounts of long PEG-chain surfactants (>10 monomers) a charge-shielding effect was observed. Replacing PEG-surfactants with PG- and an APG-surfactant did not detrimentally affect SEDDS self-emulsification, payloads or the protection of incorporated curcumin towards oxidation. PG- and APG-SEDDS bearing multiple hydroxy functions on the surface demonstrated mucus permeation comparable to PEG-SEDDS. Steric hinderance and charge-shielding of PEG-SEDDS surface substantially reduced cellular uptake up to 50-fold and impeded endosomal escape, yielding in a 20-fold higher association of PEG-SEDDS with lysosomes. In contrast, polyhydroxy-surfaces on SEDDS promoted pronounced cellular internalisation and no lysosomal co-localisation was observed. This improved uptake resulted in an over 3-fold higher inhibition of tumor cell proliferation after cytosolic curcumin delivery.

CONCLUSION

The replacement of PEG-surfactants by surfactants with polyhydroxy head groups in SEDDS is a promising approach to overcome the limitations for intracellular drug delivery associated with conventional PEGylated SEDDS surfaces.

Targeted Self-Emulsifying Drug Delivery Systems to Restore Docetaxel Sensitivity in Resistant Tumors

The use of chemotherapeutic agents such as docetaxel (DTX) in anticancer therapy is often correlated to side effects and the occurrence of drug resistance, which substantially impair the efficacy of the drug. Here, we demonstrate that self-emulsifying drug delivery systems (SEDDS) coated with enoxaparin (Enox) are a promising strategy to deliver DTX in resistant tumors. DTX partition studies between the SEDDS pre-concentrate and the release medium (water) suggest that the drug is well retained within the SEDDS upon dilution in the release medium. All SEDDS formulations show droplets with a mean diameter between 110 and 145 nm following dilution in saline and negligible hemolytic activity; the droplet size remains unchanged upon sterilization. Enox-coated SEDDS containing DTX exhibit an enhanced inhibition of cell growth compared to the control on cells of different solid tumors characterized by high levels of FGFR, which is due to an increased DTX internalization mediated by Enox. Moreover, only Enox-coated SEDDS are able to restore the sensitivity to DTX in resistant cells expressing MRP1 and BCRP by inhibiting the activity of these two main efflux transporters for DTX. The efficacy and safety of these formulations is also confirmed in vivo in resistant non-small cell lung cancer xenografts.

Orally administered self-emulsifying drug delivery system in disease management: advancement and patents

Introduction: Oral administration of a drug is the most common, ideal and preferred route of administration. The main problem of oral drug formulations is their low bioavailability arises from poor aqueous solubility of drug. Aqueous solubility of lipophilic drugs can be improved by various techniques like salt formation, complexation, addition of co-solvent etc. but self-emulsifying drug-delivery system (SEDDS) is getting more attention for increasing the solubility of such drugs. The SEDDS is an isotropic mixture of drug, lipids, and emulsifiers, usually with one or more hydrophilic co-solvents/co-emulsifiers. This system is having ability to generate oil-in-water (o/w) emulsions or microemulsions upon gentle agitation followed by dilution with aqueous phase. The SEDDSs are relatively newer, lipid-based technological innovations possessing unparalleled potential in improving oral bioavailability of poorly water-soluble drugs.Areas covered: This review provides updated information regarding the types of SEDDS, their preparation techniques, drug delivery and related recent patents along with marketed formulations.Expert opinion: The SEDDS has been explored for improving bioavailability, rising intra-subject heterogeneity, and increasing solubility. SEDDS offers the benefit of a protective effect against the hostile environment in the gut. The unique fabrication techniques provide specific strategy to overcome the low bioavailability and poor solubility problems.