Pharmacotechnical Development of a Nasal Drug Delivery Composite Nanosystem Intended for Alzheimer's Disease Treatment.

Direct nose-to-brain delivery has been raised as a non-invasive powerful strategy to deliver drugs to the brain bypassing the blood-brain barrier (BBB). This study aimed at preparing and characterizing an innovative composite formulation, associating the liposome and hydrogel approaches, suitable for intranasal administration. Thermosensitive gel formulations were obtained based on a mixture of two hydrophilic polymers (Poloxamer 407, P407 and Poloxamer 188, P188) for a controlled delivery through nasal route via liposomes of an active pharmaceutical ingredient (API) of potential interest for Alzheimer's disease.

Photopolymerization study and adhesive properties of self-etch adhesives containing bis(acyl)phosphine oxide initiator.

Objective: This paper investigates the photo-co-polymerization behavior of a blend of a diacrylamide (DEBAAP) with a phosphonylated acidic monomer using either bis(acyl)phosphine oxide or camphorquinone/amine as photo-initiator and studies the effect of variation of the structure of the phosphonylated acidic monomer on the shear bond strength to human dentin.

Methods: Photopolymerization kinetics has been assessed through the use of photo-DSC with either initiating system and with and without a phosphonic acid monomer, while the shear bond strengths (SBS) of dentin bonding agents formulated with several phosphonylated acidic monomers have been evaluated by macro SBS testing on human dentin.

Results: Photo-DSC results show that bis(acyl)phosphine oxide initiates a faster polymerization than camphorquinone/amine and that both photopolymerizations are accelerated by the phosphonic acid monomer.