Polymer-Free Injectable In Situ Forming Nanovesicles as a New Platform for Controlled Parenteral Drug Delivery Systems.

Purpose: In this study, the preparation of self-assembled polymer-free in situ forming nanovesicles (ISNs) based on non-ionic surfactants (NISs) is presented. Methods: A 2²·4¹ full factorial experimental design was adopted for the development of novel polymer-free ISNs loaded with tenoxicam utilizing the emulsion method. The type of NIS (Brij® 52 or Span® 60), the cholesterol percentage (30, 50, or 60 w/w%), and the internal phase percentage (20 or 30 v/v%) were chosen as the independent variables. Percentage drug released after 1 h (Q₁), vesicle particle size (PS), and mean dissolution time (MDT) were the dependent variables. Selected formulation was investigated morphologically using transmission electron microscopy. Results: Results revealed that the formation had spherical dense shape. All independent factors significantly affected the percentage drug release after the first hour (Q₁), and the MDT, while only the type of NIS had a significant effect on PS. The highest control of drug release was observed in formulation containing Span® 60 with lower internal phase percentage (MDT = 20.06 ± 0.40 h) as well as the smallest PS (123.75 ± 16.68 nm). Conclusion: The obtained results indicated the potentiality of the invented ISNs in controlling the release of tenoxicam in a desirable economical biphasic pattern compared to other in situ formulations. [ABSTRACT FROM AUTHOR]