Heterocyclic compounds possess diverse biological properties that have lead to intense study and research of these compounds. One of these compounds is Oxadiazole which has been found to exhibit various pharmacological activities. Oxadiazole having heterocyclic nucleus is a novel molecule which attract the chemist to search a new therapeutic molecule. The present review article covers various derivatives of different oxadiazole and their substitutions with diverse biological activities. 

In this study, synthesis of 3-[4-(5-(3,4-disubstituted phenyl)-4,5-dihydro isoxazol-3-yl) phenyl]-2-substutied phenyl Quinolin-4(3H)-one derivatives has been described. Newly Isoxazolederivatives were prepared by reaction of quinazolinone derivatives with hydroxylamine hydrochloride in presence of pyridine. A total of eight derivatives were synthesized and the compounds were purified by chromatographic methods and identified by spectroscopic methods; FTIR, H1 NMR and also by measuring its melting point. The synthesized compounds were tested for antibacterialactivity against four bacterial strains, of them two are positive strain Staphylococcus aureus and Bacillus subtilisand two gram negative strain Escherichia coliand Pseudomonas aeruginosa. The compounds were also evaluated for antifungal activity against two fungal strains and Asperigillus niger and Saccharomyces cerevisiae. The isoxazole compounds viz 3-(4-(5-(3-nitrophenyl)-4, 5-dihydroisozolyl-3-yl)- phenyl)-2-(4-nitrophenyl) quinazolin-4(3H)-one (4h), and 3-(4-(5-(3-chlorophenyl)-4, 5- dihydroisozolyl-3-yl)- phenyl )-2-(4- nitrophenyl) quinazolin-4(3H)-one (4f) derivatives were found to be quite superior in active against all organism employed in anti-bacterialaction comparable to standard drug ampicillin. The compound 4b is quite superior in its anti-fungal action and also the activity was comparable to the standard drug griseofulvin.

The purpose of present research was to develop and evaluate gastro retentive floating drug delivery system of an antiretroviral drug Zidovudine using natural polymers. The floating tablet of Zidovudine was prepared by direct compression method (effervescent method) by using natural polymers like psyllium husk powder, guar gum, xanthan gum. The results of pre-compression and post-compression parameters of all the formulated tablets were shown satisfactory results which complies with official limits. The compatibility study by FTIR confirmed that there is no interaction between the drug and the polymers used. The floating lag time and swelling index were found to be significantly increased with increasing concentration of the polymers. After the dissolution study of prepared Zidovudine floating tablet, it was concluded that the P4 formulation prepared with Psyllium husk powder shows better sustained release effect. The developed floating tablet of Zidovudine used to prolong drug release for more than 12 hrs, thereby improving bioavailability and better patient compliance.