Controlled release tablet formulations of isoxsuprine hydrochloride using direct compression technique

Isoxsuprine hydrochloride is a peripheral vasodilator. It is advisable to prepare the drug in sustained release dosage forms to improve patient compliance and to achieve a steady state blood level with minimum side effects. Different hydrophilic and hydrophobia polymers in addition to their combinations were used in different ratios to select the best level of the matrix forming material that provides the most sustaining effect. The effect of different types and concentrations of polymers on the release rate of the drug was investigated. The drug release decreased by increasing the concentration of the polymer in all the studied formulations. Tablet formula containing either 30% [w/w] HPMC 15000 or 30% [w/w] Eudragit RSPM gave the most sustaining effect among the single polymers. The drug release rate from tablets prepared using polymer blends is slower compared to that from those containing single polymers. The slowest drug release was obtained from tablet formulae containing: drug, 10% [w/w] HPMC 15000 and 40% [w/w] Eudragit RSPM and drug, 10% [w/w] Eudragit RSPM and 40% [w/w] Eudragit RLPO. The release of isoxsuprine HCl from matrices prepared using single polymer followed Higuchi 's diffusion model However, zero-order release kinetics was elucidated for the release of isoxsuprine HCl from the investigated polymer blends in phosphate buffer [pH 6.8]

Production of polyhydroxyalkanoate [PHAs] and copolymer [P[HB-co-HV]] by soil bacterial isolates in batch and two-stage batch cultures

NINETY TWO local bacterial isolates, from the rhizosphere and soil around the root system of bean [Viciafaba] grown in Kalubia Governorate in Egypt, were bio-prospected for polyhydroxyalkanoate [PHA] accumulation. Three isolates accumulated >/=20% of PHAs, they were identified as Pseudomonas flu orescens S48, Bacillus megaterium 7A and B. megaterium UBFI9. The tested isolates gave the maximum PHAs content on basal medium containing glucose and ammonium sulfate at C/N ratio of 30/1 after 72 hr at 30°C using shake flask culture technique. Two-stage batch were implemented with varying loading levels of nitrogen and phosphorus, inoculated with washed cells. Nitrogen omission of 70% led to increase the PHAs content by 19%, 3% and 8.5% using washed cells of Ps. fluorescens S48, B. megaterium UBF 19 and Bacillus megaterium 7A, respectively comparing with batch production on the same medium after 72 hr. The Copolymer poly[hydroxybutyrate-co-hydroxyvalerate] [P [HB-co-HV]] content level was increased when valerie/glucose [V/G] was 0.19 mol.mo[-1] after 96 hr being 25.97% and 20.11% by Ps. fluorescens S48 and B. megaterium UBFI9, respectively and reached 23.73% by B. megaterium 7A at propionic/glucose [PIG] of 0.5 mol.mol[-1]. The corresponding highest values of valeric content of copolymer at V/G 3.08 mol.mol[-1] were 63%, 49% and 45%, respectively, comparing with other V/G ratios by using GC analysis . Replacing glucose with 2% corn oil or 1% soybean oil increased the PHAs content of Ps. fluorescens S48 cells to 54.21% and 52.12%, respectively, after 72