Dendrimers: Amazing Platforms for Bioactive Molecule Delivery Systems

Today, dendrimers are the main nanoparticle applied to drug delivery systems. The physicochemical characteristics of dendrimers and their versatility structural modification make them attractive to applied as a platform to bioactive molecules transport. Nanoformulations based on dendrimers enhance low solubility drugs, arrival to the target tissue, drugs bioavailability, and controlled release. This review describes the latter approaches on the transport of bioactive molecules based on dendrimers. The review focus is on the last therapeutic strategies addressed by dendrimers conjugated with bioactive molecules. A brief review of the latest studies in therapies against cancer and cardiovascular diseases, as well as future projections in the area, are addressed.

Nasal Spray Device for Administration of Two-Part Drug Formulations

Intranasal drug delivery is an attractive route to noninvasively achieve a rapid therapeutic effect, avoid first pass metabolism, and bypass the blood brain barrier. However, the types of drugs that can be administered by this route has been limited, in part, by device technology. Herein, we describe a pneumatic nasal spray device that is capable of mixing liquid and solid components of a drug formulation as part of the actuation process during dose administration. The ability to store a nasal spray drug formulation as two separate components can be leveraged to solve a variety of stability issues that would otherwise preclude intranasal administration. Examples of drugs that could be delivered intranasally by utilizing this two-part formulation strategy include biomolecules that are unstable in solution and low solubility drugs that can be rendered into metastable supersaturated solutions. A proof of concept nasal spray device prototype was constructed to demonstrate that a liquid and solid can be rapidly mixed and atomized into a spray in a single action. The primary breakup distance and angle of the spray cone were measured as a function of the function of the propellant gas pressure.

Prediction of Oral Absorption of Low-Solubility Drugs by Using Rat Simulated Gastrointestinal Fluids: The Importance of Regional Differences in Membrane Permeability and Solubility

Purpose. This study aimed to develop a novel approach for predicting the oral absorption of low-solubility drugs by considering regional differences in solubility and permeability within the gastrointestinal (GI) tract. Methods. Simulated GI fluids were prepared to reflect rat in vivo bile acid and phospholipid concentrations in the upper and lower small intestine. The saturated solubility and permeability of griseofulvin (GF) and albendazole (AZ), a drug with low aqueous solubility, were measured using these simulated fluids, and fraction absorbed (Fa) at time t after oral administration was calculated. Results. The saturated solubility of GF and AZ, a drug with low aqueous solubility, differed considerably between the simulated GI fluids. Large regional differences in drugs concentration were also observed following oral administration in vivo. The predicted Fa values using solubility and permeability data of the simulated GI fluid were found to correspond closely to the in vivo data. Conclusion. These results indicated the importance of evaluating regional differences in drug solubility and permeability in order to predict oral absorption of low-solubility drugs accurately. The new methodology developed in the present study could be useful for new oral drug development. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.