Etizolam three methods were developed for estimation of etizolam in tablet dosage form. in the first uv spectrophotometric method, etizolam was estimated by measuring absorbance at λmax of 249 nm in 0.01 n hcl. in the second hptlc method, etizolam was estimated using precoated plate of silica gel 60f254 and toluene: chloroform: methanol (4.8:4.0:1.2 v/v/v) as mobile phase. in the third method, etizolam was estimated by rp-hplc method using kromasil c18 column and water: acetonitrile (50:50% v/v) as a mobile phase. the results compared well by anova test. results of hplc method also compared well with japanese pharmacopoeial method. besides, the hplc method was found to specific with respect to degradation products formed under acidic and oxidative stress conditions. etizolam+ escitalopram simultaneous equation method was developed for estimation of escitalopram and etizolam tablets by measuring absorbance at λmax of escitalopram (238 nm) and etizolam(249 nm) in 0.01 n hcl. rp-hplc ion pair chromatography method was also developed for estimation of escitalopram and etizolam using kromasil c18 column and acetonitrile:0.005 m hexane sulfonic acid ph 3.0 (adjusted with o-phosphoric acid) (40:60 v/v) as mobile phase. clonazepam: simple uv spectroscopy method was developed and validated for estimation of clonazepam in tablets. the distinctive spectral pattern of clonazepam in acidic and alkaline ph can be useful for the identification test for clonazepam. clonazepam + escitalopram: a stability indicating rp-hplc method was developed for simultaneous estimation of escitalopram oxalate and clonazepam using kromasil c18 column and methanol: 0.025 m kh2po4 buffer ph 3.0 (45:55 v/v) as mobile phase. the method successfully separated escitalopram and clonazepam from degradation products formed under stressed conditions. escitalopram degraded significantly in basic condition, while clonazepam degraded significantly under acidic, alkaline, oxidative, thermal/humidity conditions.