Publications by authors named "Jaime Conceicao"

We report the synthesis of water soluble cyclodextrin (CD) polymers prepared by crosslinking pyromellitic dianhydride (PMDA) with two CD derivatives (methyl-β-CD - MβCD and (2-hydroxy)propyl-β-CD - HPβCD) and their evaluation as functional sub-micron sized carriers in the development of antiretroviral drug delivery systems. Using the protease inhibitor lopinavir (LPV) as model drug, LPV loaded CD polymers (pHPβCD and pMβCD) were prepared and fully characterized. The physicochemical characterization and in vitro drug release confirmed the successful synthesis of pHPβCD and pMβCD, the formation of sub-micron sized particles and a 12-14 fold increase in LPV solubility.

View Article and Find Full Text PDF

The development of orodispersible tablets (ODTs) for poorly soluble and poorly flowable drugs via direct compression is still a challenge. This work aimed to develop ODTs of poorly soluble drugs by combining cyclodextrins that form inclusion complexes to improve wetting and release properties, and directly compressible co-processed excipients able to promote rapid disintegration and solve the poor flowability typical of inclusion complexes. Carbamazepine (CBZ) and hydroxypropyl-β-cyclodextrin (HPβCD) were used, respectively, as a model of a poorly soluble drug with poor flowability and as a solubilizing agent.

View Article and Find Full Text PDF

Lopinavir (LPV) is currently used in combination with ritonavir for the clinical management of HIV infections due to its limited oral bioavailability. Herein, we report the application of an in silico method to study cyclodextrin (CyD) host-guest molecular interaction with LPV for the rational selection of the best CyD for developing a CyD based LPV delivery system. The predicted CyD, a (2-hydroxy)propyl-gamma derivative with high degree of substitution (HP17-γ-CyD) was synthesized and comparatively evaluated with γ-CyD and the commercially available HP-γ-CyD.

View Article and Find Full Text PDF

This work aimed to explore for the first time the use of cyclodextrins to prepare printlets of poorly soluble drugs, such as carbamazepine, which require fine dose adjustment and rapid release. Orodispersible (flash) and immediate release formulations were 3D printed via semisolid extrusion of wet masses of hydroxypropyl-β-cyclodextrin (HPβCD) and cellulose ethers and regulating tablet porosity. Rheology of the wet masses allowed identifying printable compositions.

View Article and Find Full Text PDF

Cyclodextrins are cyclic carbohydrates widely used as complexing and non-complexing excipients in drug delivery systems. The purpose of this work was to study the ability of hydroxypropyl-β-cyclodextrin and β-cyclodextrin to act as tablet fillers for direct compression. In this way, several parameters of the cyclodextrins were evaluated, namely: (i) the flow properties such as angle of repose, flow time, Carr index, and Hausner ratio; (ii) the compaction behavior, specifically the energies and forces exerted during tableting, the plasticity index, the lubrication efficiency, and compression profiles (force/time and work/displacement of the upper punch); and (iii) the influence on carbamazepine release characteristics from uncoated tablets, i.

View Article and Find Full Text PDF

This paper aims to provide a critical review of cyclodextrins as excipients in tablet formulations, highlighting: (i) the principal pharmaceutical applications of cyclodextrins; (ii) the most relevant technological aspects in pharmaceutical formulation development; and (iii) the actual regulatory status of cyclodextrins. Moreover, several illustrative examples are presented. Cyclodextrins can be used as complexing excipients in tablet formulations for low-dose drugs.

View Article and Find Full Text PDF

Background: Cyclodextrins (CDs) are versatile excipients with an essential role in drug delivery, as they can form non-covalently bonded inclusion complexes (host-guest complexes) with several drugs either in solution or in the solid state.

Methods: The main purpose of this publication was to carry out a state of the art of CDs as complexing agents in drug carrier systems. In this way, the history, properties and pharmaceutical applications of the CDs were highlighted with typical examples.

View Article and Find Full Text PDF

Cancer is a term used for a heterogeneous group of malignant diseases in which abnormal cells divide without control and are able to invade other tissues, resulting in metastasis. According to the last data of World Health Organization the incidence and mortality rates of cancer are high and tend to increase. Chemotherapy is usually used in cancer treatments, but due to the lack of specificity of drugs, is associated to various and damaging side effects that have a severe impact on patients quality of life.

View Article and Find Full Text PDF