Formulation and Release Characteristics of Zidovudine-Loaded Solidified Lipid Microparticles

Purpose: To formulate and determine the release profile of zidovudine (AZT)-loaded solidified lipid microparticles (SLMs).Methods: Different concentrations (0, 1, 2, 3 and 5 %w/w) of zidovudine (AZT) were formulated into microparticles in melt dispersion of Phospholipon® 90H and goat fat in the ratio 1:1, 2:1, 2:3 and 1:3 followed by lyophilization. They were characterized for particle size, yield, entrapment efficiency (EE) and loading capacity (LC). In vitro release kinetics and mechanism of release were assessed sequentially in simulated gastric fluid (SGF, pH 1.2)and simulated intestinal fluid (SIF, pH 7.2).Results: The ratio 1: 1 formulation was the most stable in terms of physical observation.. Particle size analysis indicated that the particles were irregular in shape with size ranging from 5.10 ± 0.10 to 13.40 ± 2.20 μm. Yield decreased with increase in drug concentrations in the SLMs formulations. EE data showed that the microparticles containing 1 % w/w of AZT had the highest entrapment efficiency of 74.0 ± 0.03 %. LC also decreased with increase in concentration of AZT. AZT tablet released most of its content within 5 min with a sharp decrease in the concentration but the SLMs maintained its release for 8 to 12 h in different batchesConclusion: The results show that drug content has influence on drug release from the SLMs, but not on the mechanism of release. Furthermore, dose dumping was avoided and drug release mechanism was mostly non-Fickian while for the reference (commercial) tablet, it was Fickian.Keywords: Phospholipon® 90H, Solidified lipid microparticles, Solidified reverse micellar microparticle, Zidovudine

Novel lipid-based dermal microgels of Neobacin®

This study investigates the potential of novel microgles based on solid lipid microparticles (SLMs) as a sustained delivery system for neobacin®, a topical antibiotic drug powder. Matrices generated from sunseed oil and goat fat (1:9, 2:8 and 3:7) was surface-modified with Phospholipon® 90G and employed to formulate SLM-based microgels. The microgels were characterized in terms of in vivo wound healing in rats, in vitro permeation, membrane drug retention studies and antimicrobial activity against various microorganisms using standard cup-plate agar diffusion method. The 3:7 microgels exhibited sustained release property, achieving 34% drug permeation over 12 h, 64% membrane drug retention and largest growth inhibition zone diameters (IZD) on all organisms, whereas commercial neobacin® gel achieved 35% drug permeation at 4 h and 72% membrane drug retention. In vivo wound healing followed this order 3:7>1:9>2:8 better than neobacin® powder. Neobacin® microgel formulation despite rapid degradation possessed greater wound healing and antimicrobial property than the conventional powder form of neobacin®.  Key words: Microgels, surface-modified solid lipid microparticles, sustained release, neobacin®

Water Quality of Trickling Biological Periwinkle Shells Filter for Closed Recirculating Catfish System

Studies were carried on the design, efficiency and economics of trickling biological periwinkle shells filter in recirculating aquaculture systems for catfish production. The designed biofilter and other system components were constructed, assembled and commissioned for pilot catfish production. The system with the designed biofilter served as the treatment system, while that without biofilter served as the control system. Data were collected daily (except for BOD5) on water quality parameters such as total ammonia-nitrogen (TAN), nitrite-nitrogen, unionized ammonia–nitrogen (UAN), pH, dissolved oxygen (DO), surface water temperature, secchi transparency, total alkalinity, Chloride content, total hardness  free carbon dioxide and biochemical oxygen demand (BOD). The Total length and weight of fish stocked in the treatment and control systems were measured at the beginning of the study and subsequently every four weeks. Results showed that total ammonia–nitrogen for the treatment system ranged from 0.00 to 4.00 ppm, with a mean of 1.26±0.92 ppm, while that of the control varied from 0.00 to 6.50 ppm, with a mean of 2.23±1.80 ppm. The nitrite–nitrogen values of the treatment system ranged from 0.00 to 1.80 ppm, with a mean of 0.67±0.40 ppm, while that of the control system ranged from 0.00 to 2.50 ppm, with a mean of 1.18±0.79 ppm. The un-ionized ammonia–nitrogen values for the treatment system varied from 0.000 to 0.022 ppm, with a mean of 0.007±0.006 ppm, while that of the control system ranged from 0.000 to 0.036 ppm, with a mean of 0.015±0.016 ppm. Results of fish growth showed that final fish weight for the treatment system ranged from 287.50 to 1280.00 g, with a mean of 765.35±259.24 g, while that of the control ranged from 50.00 to 800.00 g, with a mean of 490.31±185.65 g. Mean value of final fish weight stocked in the treatment system was significantly (p<0.05) higher than that of the control. Apart from total hardness, nitrite–nitrogen and unionized ammonia-nitrogen the mean values of all other water quality parameters for the treatment system were not significantly (p>0.05) different from that of the control system. It is therefore concluded that the trickling biological periwinkle shells filter provided adequate biological water treatment for closed recirculating catfish system.       Keywords: Water quality, Periwinkle shells biofilter, recirculating catfish syste

The Efficiency of Periwinkle Shells Filter as Biofilter Medium in Closed Recirculating Catfish Systems

Studies were carried out for twelve 12 weeks on the design, efficiency and economics of biofilter using periwinkle, Tympanotonus fuscatus, fuscatus, var radula: shells as biofilter medium in recirculating aquacuture system (RAS). The designed biofilter and the other designed system components were constructed, assembled and commissioned for a pilot mud catfish (Clarias gariepinus) production. The system with the designed biofilter served as the treatment system, while the control system had no biofilter. The efficiency of the biofilter was computed daily using the total ammonia-nitrogen (TAN) method. The biofilter efficiency indicators water quality, nitrite-nitrogen, unionized ammonia-nitrogen and total ammonia-nitrogen (TAN) of treatment and control systems were monitored daily except biochemical oxygen demand (BOD). The total length and weight (WT) of fish stocked in the treatment and control systems were measured at the beginning of the study and subsequently every four weeks. Results showed that biofilter efficiency of the treatment system varied from 0.00 to 100.00%, with a mean of 54.78+23.95%. The value of TAN for the treatment system ranged from 0.00 to 4.00 ppm, with a mean of 1.26+0.92 ppm, while that of control system ranged from 0.00 to 6.80 ppm, with a mean of 2.23+1.80 ppm. The nitrite-nitrogen value for the treatment system ranged from 0.00 to 1.80 ppm with a mean of 0.66+0.49 ppm, while that of the control ranged from 0.00 to 2.50 ppm with a mean of 1.18+0.79 ppm. The unionized ammonia-nitrogen value varied from 0.000 to 0.022 ppm, with a mean of 0.007+0.006 ppm for the treatment system, while that of the control ranged from 0.000 to 0.036 ppm with a mean of 0.015+0.016 ppm. Final fish weight for the treatment system ranged from 287.50 to 1280.00 g, with a mean of 765.35+259.24 g, while that of the control ranged from 50.00 to 800.00 g with a mean of 490.31+185.69 g. Results of statistical analysis showed that mean values of nitrite-nitrogen, unionized ammonia-nitrogen and final fish weight obtained for the treatment system were significantly (p<0.05) lower than that of the control system. Mean values of TAN, surface water temperature, pH, chloride and other water quality parameters for the treatment system were not significantly (p>0.05) different from that of the control. It was concluded, therefore, that periwinkle shell was suitable as natural biofilter medium in closed recirculating catfish systems. Keywords: Periwinkle shells, catfish, aquaculture, biofilter medium, closed recirculating syste

The design of trickling biological periwinkle shells filter for closed recirculation catfish systems

The design efficiency and economics of biofilter in reirculating aquaculture systems using local material as biofilter was carried out for 12 weeks. The type of trickling biofilter selected was vertical flow. The local, natural material selected as biofilter medium was periwinkle shells. The designed biofilter and other system components were constructed, assembled and commissioned for pilot fish production using catfish-Clarias gariepinus. The system with the designed biofilter served as the treatment system, while the system without biofilter served as the control system. Results of the biofilter design were 2.0 m depth, 150 m2 surface area, 226 m2/m3 specific surface area and 0.35 m2 cross sectional area. The specifications of the fish tank were 0.29 m radius, 0.90 m height, 0.21 m3 volume and 0.10 m free board. The results of the design of the sedimentation tank were 1.40 m length, 1.0 m width, 1.0 m depth, 2.0 hours detention time, 0.42 mm/sec settling velocity and 600 angle of inclination of the settling plates. The lift pump selected had the following specifications, 0.50 Hp power, 2.10 m3/hr discharge and 35.00 m head. The diameter of the perforation on the bottom of the distribution plate was 6.00 mm, while clearance was 0.3 m. The selected system recirculation rate was 10 times per hour, while the selected system recirculation ratio was 90% per day. Data from pilot fish production showed that mean values of final total length (TL) and weight of fish stocked in the treatment system were significantly (p<0.05) higher than that of the control. The result of the total ammonia-nitrogen (TAN), for the treatment system ranged from 0.00 to 4.00 ppm with a mean of 1.26+0.92 ppm, while that of the control varied from 0.00 to 6.80 ppm with a mean of 2.23+1.80 ppm. The nitrite-nitrogen values for the treatment system ranged from 0.00 to 1.80 ppm with a mean of 0.66+0.49 ppm while that of the control ranged from 0.00 to 2.50 ppm with a mean of 1.18+0.79 ppm. The unionized ammonia-nitrogen value (UAN) for the treatment system ranged from 0.000 to 0.022 ppm with mean of 0.007+ 0.006 ppm, while that of the control system ranged from 0.000 to 0.036 ppm, with a mean of 0.015+0.016 ppm. The mean values of nitrite-nitrogen and unionized ammonia-nitrogen for the treatment systems were significantly (p<0.05) lower than that of the control, while TAN mean value in the treatment system was not significantly (p>0.5) lower than that of the control system. Result of biofilter efficiency ranged from 0.00 to 100.00%, with a mean of 54.78+23.95%. Data on other water quality parameters such as DO, pH, temperature, BOD5, Seechi transparency, total alkalinity, free carbon dioxide, chloride, etc. in the treatment system were not significantly (p>0.05) different from that of the control system. We concluded that periwinkle shell is a suitable trickling filter medium for closed recirculation catfish system.Keywords: Periwinkle shells medium, closed recirculating catfish system, biofilter designInternational Journal of Natural and Applied Sciences, 6(3): 272-280, 201

Evaluation of Gentamicin-Entrapped Solid Lipid Microparticles Formulated with a Biodegradable Homolipid from Capra hircus

Purpose: To formulate solidified reverse micellar solutions (SRMS)-based solid lipid microparticles (SLMs) using homolipid from Capra hircus, and evaluate its suitability for the delivery of gentamicin.Methods: SLMs were formulated by melt-emulsification using SRMS (15 % w/w Phospholipon® 90G in 35 % w/w Capra hircus), PEG 4000 and  gentamicin (1.0, 2.0 and 3.0 % w/w), and characterized with respect to size, morphology, encapsulation efficiency (EE) and pH-dependent stability. In vitro release of gentamicin from the SLMs was performed in phosphate buffer (pH 7.4) while bioevaluation was carried out using clinical isolates of Pseudomonas aeruginosa and Staphylococcus aureus.Results: Stable and discrete SLMs of size range 1.47 ± 0.02 to 3.55 ± 0.09 µm were obtained. The SLMs showed a biphasic pattern of drug release and exhibited time-dependent and capacity-limited bioactivity. Overall, SLMs containing 2 % w/w SRMS, 3 % w/w gentamicin and PEG 4000 entrappedthe highest amount of drug, released 99 % of drug and gave the highest inhibitory zone diameter (IZD) against the organisms within 420 min, while plain gentamicin gave the least.Conclusion: SRMS-based SLMs prepared with homolipid from Capra hircus offers a suitable delivery system for gentamicin.Keywords: Solid lipid microparticles, Gentamicin, Capra hircus,   Phospholipon® 90 G, Solidified reverse micellar solutio

Case report - Lassa Fever Mimicking Ectopic Pregnancy: A Report Of Three Cases

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Sustained-release liquisolid compact tablets containing artemether-lumefantrine as alternate-day regimen for malaria treatment to improve patient compliance

Petra Obioma Nnamani,1,2 Agatha Adaora Ugwu,1 Emmanuel Chinedu Ibezim,1 Franklin Chimaobi Kenechukwu,1 Paul Achile Akpa,1 John-Dike Nwabueze Ogbonna,1 Nicholas Chinedu Obitte,3 Amelia Ngozi Odo,4 Maike Windbergs,2 Claus-Michael Lehr,2,5,6 Anthony Amaechi Attama1 1Drug Delivery and Nanomedicines Research Group, Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, University of Nigeria, Nsukka, Nigeria; 2Department of Drug Delivery, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research, Saarland University, Saarbrücken, Germany; 3Department of Pharmaceutical Technology and Industrial Pharmacy, Faculty of Pharmaceutical Sciences, 4Department of Human Kinetics and Health Education, University of Nigeria, Nsukka, Nigeria; 5PharmBioTec GmbH, 6Department of Biopharmaceutics and Pharmaceutical Technology, Saarland University, Saarbrücken, Germany Abstract: The present study aimed to develop low-dose liquisolid tablets of two antimalarial drugs artemether–lumefantrine (AL) from a nanostructured lipid carrier (NLC) of lumefantrine (LUM) and estimate the potential of AL as an oral delivery system in malariogenic Wistar mice. LUM-NLCs were prepared by hot homogenization using Precirol® ATO 5/Transcutol® HP and tallow fat/Transcutol® HP optimized systems containing 3:1 ratios of the lipids, respectively, as the matrices. LUM-NLC characteristics, including morphology, particle size, zeta potential, encapsulation efficiency, yield, pH-dependent stability, and interaction studies, were investigated. Optimized LUM-NLCs were mixed with artemether powder and other dry ingredients and the resultant powder evaluated for micromeritics. Subsequent AL liquisolid tablets were tested for in vitro drug release and in vivo antiplasmodial activity in mice infected with Plasmodium berghei berghei (NK 65). Results showed that optimized LUM-NLC were stable, spherical, polydispersed but nanometric. Percentage yield and encapsulation efficiency were ~92% and 93% for Precirol® ATO 5/Transcutol® HP batch, then 81% and 95% for tallow fat/Transcutol® HP batch while LUM was amorphous in NLC matrix. In vitro AL release from liquisolid compacts revealed initial burst release and subsequent sustained release. Liquisolid tablet compacts formulated with Precirol® ATO 5/Transcutol® HP-AL4 achieved higher LUM release in simulated intestinal fluid (84.32%) than tallow fat/Transcutol® HP-BL3 (77.9%). Non-Fickian (anomalous) diffusion and super case II transport were the predominant mechanisms of drug release. Equal parasitemia reduction was observed for both batches of tablet compacts (~92%), superior to the reduction obtained with commercial antimalarial formulations: Coartem® tablets (86%) and chloroquine phosphate tablets (66%). No significant difference (P<0.05) in parasite reduction between double (4/24 mg/kg) and single (2/12 mg/kg) strength doses of AL compacts was observed. Our result highlights that AL could be formulated in much lower doses (4/24 mg/kg), for once-in-two days oral administration to improve patient compliance, which is currently not obtainable with conventional AL dosage forms. Keywords: malaria, artemisinin-based combination therapy, antiplasmodial activity, liquisolid compacts, nanostructured lipid carrier