Different HPMC viscosity grades as coating agents for an oral time and/or site-controlled delivery system: a study on process parameters and in vitro performances

Abstract Chagas disease (CD), caused by the flagellate protozoan Trypanosoma cruzi, is one of the major public health problems in developing countries. Benznidazole (BNZ) is the only drug available for CD treatment in most countries, however, it presents high toxicity and low bioavailability. To address these problems this study used Zeolitic Imidazolate Framework-8 (ZIF-8), which has garnered considerable attention due to its potential applications, enabling the controlled delivery of drugs. The present work developed and characterized a BNZ@ZIF-8 system, and the modulation of BNZ release from the ZIF-8 framework was evaluated through the in vitro dialysis release method under sink conditions at different pH values. Moreover, the in vitro evaluation of cell viability and cytotoxicity by MTT assay were also performed. The dissolution studies corroborated that a pH sensitive Drug Delivery System capable of vectorizing the release of BNZ was developed, may leading to the improvement in the bioavailability of BNZ. The MTT assay showed that no statistically significant toxic effects occurred in the developed system, nor significant effects on cell viability.

Download Full-text

Boar semen controlled-delivery system: morphological investigation and in vitro fertilization test

Reproduction Fertility and Development ◽

10.1071/rd02004 ◽

2002 ◽

Vol 14 (5) ◽

pp. 307 ◽

Cited By ~ 15

Author(s):

Daniele Vigo ◽

Massimo Faustini ◽

Maria Luisa Torre ◽

Alessandro Pecile ◽

Simona Villani ◽

...

Keyword(s):

Electron Microscopy ◽

Controlled Release ◽

In Vitro Fertilization ◽

Delivery System ◽

Release Kinetics ◽

Membrane Integrity ◽

Controlled Delivery ◽

Vitro Fertilization ◽

Starting Point

A technology for encapsulation of swine semen in barium alginate and protamine alginate has recently been proposed for the controlled release of the spermatozoa, thus reducing the number of instrumental inseminations required. Controlled-release capsules containing swine spermatozoa were prepared by adding saturated BaCl2 solution to ejaculate and dropping the resulting suspension into a sodium alginate solution, leading to the formation of barium alginate capsules. A second type of capsule was obtained by cross-linking the barium alginate with protamine sulfate. Two types of membrane were thus obtained: barium alginate gel and a protamine cross-linked alginate membrane. Morphological (scanning electron microscopy and transmission electron microscopy), functional (motility, membrane integrity and in vitro fertilization test) and technological (capsule structure and weight) approaches were used to characterize the encapsulated spermatozoa and the controlled-delivery system. No differences in terms of morphological and functional characteristics (acrosome integrity and spermatozoa motility) between free and encapsulated semen were found. The technological process did not compromise in vitro fertilization potency of the spermatazoa, although seasonal variability was found. The capsule weight was related to either the pH of the semen or the season. This study represents the starting point for the development of further investigations into the storage and release kinetics of cells from the capsules and for the development of an in vivo fertilization protocol.

Download Full-text