Fused triazolothienopyrimidines were prepared from the corresponding 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile. These precursors were intern prepared by employing the Gewald's reaction. All the newly synthesized compounds were characterized by spectral and analytical data. Title compounds displayed promising antibacterial and antifungal activities. Compound 3h which exhibited good antimicrobial activity was incorporated into SLN and characterized for particle size, entrapment efficiency (EE%), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and in-vitro release studies. It showed narrow particle size distribution with high entrapment efficiency. In-vitro release study of compound loaded SLNs in phosphate buffer of pH 7.4, exhibited a biphasic pattern with an initial burst and prolonged release over 24 h.