Simultaneous quantification of stavudine, lamivudine and nevirapine by UV spectroscopy, reverse phase HPLC and HPTLC in tablets.

In the present study, simultaneous quantification of stavudine (SV), lamivudine (LV) and nevirapine (NV) in tablets by UV spectroscopy, reverse phase HPLC (RP-HPLC) and HPTLC methods were developed. In the UV multi-component spectral method, SV, LV and NV was quantified at 266, 271 and 315 nm, respectively. In the RP-HPLC method, the drugs were resolved using a mobile phase of 20 mM sodium phosphate buffer (containing 8 mM 1-octanesulphonicacid sodium salt):acetonitrile (4:1, v/v) with pH adjusted to 3.5 using phosphoric acid on a C18-ODS-Hypersil (5 microm, 250 mm x 4.6 mm) column in isocratic mode. The retention time of SV, LV and NV was 2.85, 4.33 and 8.39 min, respectively. In the HPTLC method, the chromatograms were developed using a mobile phase of chloroform:methanol (9:1, v/v) on precoated plate of silica gel 60 F254 and quantified by densitometric absorbance mode at 265 nm. The Rf of SV, LV and NV were 0.21-0.27, 0.62-0.72 and 0.82-0.93, respectively. Recovery values of 99.16-101.89%, percentage relative standard deviation of <0.7 and correlation coefficient (linear dynamic range) of 0.9843-0.9999 shows that the developed methods were accurate and precise. These methods can be employed for the routine analysis of tablets containing SV, LV and NV.

Synthesis and biological activities of 2,6-diaryl-3-methyl-4-piperidone derivatives.

In the present study, a new series of 2,6-diaryl-3-methyl-4-piperidones was synthesized by Mannich reaction (condensation) of ethyl-methyl ketone, substituted aromatic aldehydes and ammonium acetate. Oximes and thiosemicarbazone derivatives of 2,6-diaryl-3-methyl-4-piperidones were synthesized by reaction with hydroxylamine hydrochloride and thiosemicarbazide respectively. The chemical structures were confirmed by means of IR, 1H-, 13C-NMR and mass spectral data. The compounds were screened for acute toxicity, analgesic, local anaesthetic and antifungal activity. 2-(4-Methylphenyl)-3-methyl-6-(4-chlorophenyl)-piperidin-4-one 2 exhibited the highest analgesic and local anaesthetic activity. The oximes and thiosemicarbazones were completely devoid of analgesic and local anaesthetic activity. 2-(4-Methylphenyl)-3-methyl-6-(4-hydroxyphenyl)-piperidin-4-oxime 21 and 2-(4-methoxyphenyl)-3-methyl-6-(4-chlorophenyl)-piperidin-4-oxime 17 exhibited potent antifungal activity against Aspergillus niger. Antifungal activity against Candida albicans was observed only with 2-(4-dimethylaminophenyl)-3-methyl-6-(4-chlorophenyl)-piperidin-4-oxime 20. 2,6-Diaryl-3-methyl-4-piperidones did not exhibit antifungal property.