Preformulation activities of intranasal dosage forms of temazepam

Bioadhesive excipients are used in intranasal drug delivery to prolong the residence time of formulations al the absorption site with the aim of improving the biopharmaceutical properties of the active drug. Bioadhesive starch, obtained by a high energy grinding process starting from a waxy starch (that does not possess any bioadhesive properties), has been employed to prepare different intranasal temazepam-starch formulations. Physico-chemical characterization of these formulations has been performed by means of rheological, thermal, chromatographic and particle size distribution tests both after the preparation processes and during a 6-month storage period in different temperature and relative humidity conditions. All formulations revealed good bioadhesive properties after the manufacturing processes and a good chemical and physico-chemical stability during aging.