Chitosan microencapsulation of the dispersed phase of an O/W nanoemulsion to hydrochlorothiazide delivery

Abstract

In view of biopharmaceutical limitations of hydrochlorothiazide (HCTZ), Trojan-type mucoadhesive systems were proposed, aiming to improve HCTZ pharmacological properties by modulating its release. Nanoemulsions were formed spontaneously by combining medium-chain triglycerides (Lipoid^® S75 and Pluronic^® F68) and high encapsulation efficiency was obtained. The mucoadhesive properties were provided by chitosan and microencapsulation of nanoemulsions in spray-dryer was successfully achieved by using Aerosil^® as wall material. The rapid redispersion of nanoemulsion in simulated fluids led to a fast and complete release of HCTZ in gastric medium. The pharmacodynamics of HCTZ was improved, extending the diuretic activity. Once a simple and low-energy method contributed to obtain stable mucoadhesive nanoemulsions, advantages in terms of production could also be achieved, allowing easy scaling up. This novel mucoadhesive Trojan particulate system of HCTZ showed to be a promising approach to overcome limitations in terms of absorption and consequently improve the therapeutic efficacy.

Keywords:

• Diuretic activity
• hydrochlorothiazide
• microencapsulation
• mucoadhesion
• nanoemulsion
• Trojan system

Acknowledgements

The authors would like to thank LCME/UFSC for technical support during microscopy analysis, Flora Lucena Sant’ana for her skilful assistance with the in vivo studies and Dr. José Eduardo da Silva Santos, who kindly allowed the use of the metabolic cages.

Disclosure statement

The authors report no conflicts of interest.

Additional information

Funding

This study was supported by the National Council for Scientific and Technological Development (CNPq) and Coordination for the Improvement of Higher Education Personnel (CAPES).