Orlistat-loaded solid SNEDDS for the enhanced solubility, dissolution, and in vivo performance.

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems
• Nanotechnology

Background:

• Orlistat is an anti-obesity agent with poor solubility and bioavailability.
• Developing effective drug delivery systems is crucial for enhancing orlistat's therapeutic efficacy.
• Solid self-nanoemulsifying drug delivery system preconcentrate (SSP) offers a promising approach to overcome these limitations.

Purpose of the Study:

• To develop an orlistat-loaded SSP using minimal lipid excipients.
• To enhance orlistat's solubility, in vitro dissolution, and lipase inhibition.
• To evaluate the in vivo performance of the developed SSP formulation.

Main Methods:

• Screening of solubilizing vehicles, selecting Solutol HS15 (surfactant) and Lauroglycol 90 (oil).
• Construction of a pseudo-ternary phase diagram to identify SSP regions.
• Characterization of SSP properties including particle size, melting point (DSC), and crystallinity (XRD).
• In vitro dissolution and lipase inhibition assays.
• In vivo study in rats to assess fat absorption reduction.

Main Results:

• Developed an orlistat-loaded SSP (55/40/5 weight ratio) with a melting point of 32.23°C.
• The SSP formed uniform nanoemulsions with particle sizes of 141.7±1.1 nm in water.
• Achieved 98.12% orlistat dissolution within 45 minutes at pH 1.2, compared to negligible dissolution for raw orlistat.
• Demonstrated 90.42% lipase inhibition within 45 minutes.
• Significantly increased fecal fat excretion in rats compared to raw orlistat (P<0.05).

Conclusions:

• The novel orlistat-loaded SSP formulation is effective in enhancing solubility and dissolution.
• The SSP exhibits significant lipase inhibition and improved in vivo fat absorption reduction.
• This formulation represents a promising candidate for effective obesity treatment.