Preparation and in vitro/in vivo evaluation of mucosal adjuvant in situ forming gels with diphtheria toxoid. (March 2014)

• Record Type: Journal Article
• Authors: Ozbılgın, Nalan Deniz; Saka, Ongun Mehmet; Bozkır, Asuman
• Is Part Of: Drug delivery. Volume 21:Number 2(2014:Feb.)
• Page Start: 140
• Page End: 147
• Publication Date: 2014-03
• Subjects: Drug delivery systems -- Periodicals; Drug targeting -- Periodicals; 615.05
• DOI: 10.3109/10717544.2013.834754
• Languages: English
• ISSNs: 1071-7544

Abstract

<abstract> <title>Abstract</title> <p>Studies on preparation of <italic>in situ</italic> gel formulations containing diphtheria toxoid as the model active substance and their intranasal administration have been conducted in this study. The objective of mucosal vaccination is to stimulate both systemic and mucosal immune responses. <italic>In situ</italic> gel formulations were prepared by using, in different ratios, mixtures of Poloxamer 407 and Poloxamer 188 polymers, which gelate in a temperature-dependent manner, and mucoadhesive polymers carbopol 934, hydroxypropyl methyl cellulose, hydroxypropyl cellulose or chitosan. Following pre-formulation studies, F1, F2, F3, F4, F5, F6 and F7 formulations, which gelate at intervals and temperatures in accordance with nasal temperatures, were subjected to more comprehensive studies. For this purpose, organoleptic characteristics of the formulations were identified, their pH and mucoadhesive potencies were measured and rheological behaviors were characterized. Calculated amounts of diphtheria toxoid were added to formulations after optimization of formulations was achieved, and assay and <italic>in vitro</italic> release studies were carried out. Formulations coded F3 and F7 were considered to be superior to other formulations given the <italic>in vitro</italic> test results. Therefore, these formulations were tested in guinea pigs to determine immune responses, which they would produce following intranasal and subcutaneous administration. Absorbance values of ELISA tests and antibody neutralization test showed that formulations coded F3 and F7 were unable to stimulate adequate systemic immune response when either of the formulations was administered alone intranasally, whereas F7 resulted in significantly increased neutralizing antibody titers with intranasal administration as a booster dose following subcutaneous administration.</p> </abstract>