Authors:A. Azeem, M. Rizwan, F. J. Ahmad, Z. Iqbal, R. K. Khar, M. Aqil, and S. Talegaonkar
An accurate, sensitive, precise, rapid and isocratic reversed-phase HPLC (RPHPLC) method for analysis of buspirone in the bulk drug and in solid dosage formulations has been developed and validated. The best separation was achieved on a 250 mm × 4.6 mm i.d., 5-μm particle, RP C18 column with 70:30 (υ/υ) methanol-0.01 m sodium dihydrogen phosphate buffer (pH 3.5) as mobile phase at a flow rate of 0.8 mL min−1. UV detection was at 244 nm. Response was a linear function of concentration over the range 0.05–20 μg mL−1 (r = 0.9998) and the limits of detection and quantitation were 3.7 and 11.3 ng mL−1, respectively. The method was validated in accordance with ICH guidelines. The drug was subjected to oxidative, hydrolytic, photolytic, and thermal stress. Degradation products produced as a result of this stress did not interfere with detection of buspirone and the assay can thus be regarded as stability-indicating. The method was used for quantification of buspirone in commercial buspirone tablets and to check content uniformity. The excipients present in the formulation did not interfere with the assay. The method is suitable for application in quality-control laboratories, because it is simple and rapid with good accuracy and precision.
Authors:M. W. Abbasi, M. Q. Khan, M. J. Zaki, S. S. Shaukat, A. Rauf, N. Ahmed, M. Azeem, and M. Tariq
Bacillus thuringiensis (B.t) is well known for its biocontrol potential against a variety of insects. Nematicidal potential of ten B.t isolates was tested against root-knot nematodes (Meloidogyne javanica (Treub) Chitwood) in vitro, under greenhouse as well as in field conditions. Eggs and second stage juveniles (J2) were exposed to 5 and 25% concentrations of bacterial cell-free aqueous extracts up to 96 h. B.t isolates showed lesser degrees of nematicidal activity at 5% concentration. However, some B.t isolates (B.t-14, B.t-16 and B.t-64) greatly reduced egg hatching and increased J2. All B.t isolates revealed suppressed egg hatching and increased mortality of J2 at 25% concentration. Soil applications with most of the B.t isolates under greenhouse and field conditions significantly improved height and fresh weights of root-knot nematode parasitized okra (Abelmoschus esculentus (L.) Moench). Some isolates, including B.t-64 reduced the number of galls and egg masses. B.t-64 reduced gall formation up to 70% under greenhouse conditions. However, 29% of decrease was observed in field conditions. Similarly, B.t-64 treated plants showed a 56% decreased in eggs/egg mass in a field experiment. Population of root-knot nematodes in the rhizosphere was decreased up to 61% in the field experiment as compared to control.