Chitosan-coated alginate (CCA) nanoparticles for augmentation of topical antihistaminic activity of diphenhydramine: optimization, skin histopathology and pharmacodynamic studies with in vitro/in vivo correlation.

Objective: The aim of the present study was to formulate chitosan-coated alginate nanoparticles containing the drug diphenhydramine hydrochloride (DHH).

Significance: Diphenhydramine hydrochloride (DHH) is the prototype of H-antihistaminic drugs. It is a lipophilic drug, that easily crosses the blood-brain barrier when taken orally causing decrements in alertness and performance.

Drotaverine Hydrochloride Superporous Hydrogel Hybrid System: a Gastroretentive Approach for Sustained Drug Delivery and Enhanced Viscoelasticity.

This study aims to prepare drotaverine hydrochloride superporous hydrogel hybrid systems (DSHH systems) to prolong its residence time in the stomach, provide extended release and reduce its frequency of administration. Drotaverine hydrochloride (DRH) is a spasmolytic drug that suffers from brief residence due to intestinal hypermotility during diarrheal episodes associated with gastrointestinal colics resulting in low bioavailability and repeated dosing. Eight DSHH systems were prepared using gas blowing technique.