Phospholipon 90H(P90H)-based PEGylated microscopic lipospheres delivery system for gentamicin:an antibiotic evaluation

Objective:To formulate gentamicin liposphere by solvent-melting method using lipids and polyethylene glycol 4000(PEG-4000) for oral administration.Methods:Gentamicin lipospheres were prepared by melt-emulsification using 30%w/w Phospholipon(?) 90H in Beeswax as the lipid matrix containing PEC-4000.These lipospheres were characterized by evaluating on encapsulation efficiency,loading capacity,change in pH and the release profile. Antimicrobial activities were evaluated against Escherichia coli,Pseudomonas aeruginosa. Salmonella paratyphii and Staphylococcus aureus using the agar diffusion method.Results: Photomicrographs revealed spherical particles within a micrometer range with minimal growth after 1 month.The release of gentamicin in vitro varied widely with the PEC-4000 contents. Moreover,significant(P>0.05) amount of gentamicin was released in vivo from the formulation. The encapsulation and loading capacity were all high,indicating the ability of the lipids to take up the drug.The antimicrobial activities were very high especially against Pseudomonas compare to other test organisms.This strongly suggested that the formulation retain its bioactive characteristics.Conclusions:This study strongly suggest that the issue of gentamicin stability and poor absorption in oral formulation could be adequately addressed by tactical engineering of lipid drug delivery systems such as lipospheres.

Anticariogenic potentials of clove,tobacco and bitter kola

Objective:To investigate three tropical plant materials - clove seeds[Syzygium aromalicum(S. aromaticum)],bitter kola fruits[Garcinia kola(G.kola)]and tobacco leaves(Nicotiana species) as potential targeted killers of Streptococcus mutans(S.mutatis),a cavity-causing bacterium(gram-positive, facultative anaerobe) that resides in a multispecies microbial community(dental plaque) for the treatment of dental caries(tooth decay).Methods:Thirty one(31) teeth samples were collected from patients with obvious signs of tooth decay(swollen gum,weak or fallen tooth,etc.) using sterile swab sticks.These samples were collected from two major denial clinics in Nsukka, Enugu State,Nigeria and investigated by spread inoculation onto sterile blood agar and Mueller Hinton agar(MHA) respectively and incubated at 37℃for 24 h.The discrete colonies obtained were further re-inoculated onto sterile Mitis salivarius agar(MSA) plates and incubated as above. The isolates were characterized by gram staining and calalase lesl.Tobacco leaves,clove seeds and bitter kola fruits were ground into powder,extracted with three different solvents(n-hexane, hot water and ethanol),filtered,dried and stored in clean containers,corked and kept until used. The plant extracts were investigated for phytochemistry,minimum inhibitory concentration(MIC), minimum cidal concentration(MCC)and compared with some conventional antibiotics commonly used against tooth decay.Antibiotic sensitivity test was also carried out.The results were statistically analyzed.Results:The extracts showed varied phytochemical composition but most abundantly the flavonoids.Our result also shows that females(16) have more tooth decay than males(15) and that 16 samples were very bloody while 15 were slightly bloody.The microbial characterization showed that 18 samples were catalase-positive indicating the presence of S. mutans while 13 were catalase-negative suspected to be Staphylococcus spp.The Gram reaction confirmed 13 Gram-negative and 18 Gram-positive organisms.The n-hexane extract had the best antimicrobial activity followed by the ethanol and lastly hot water.MIC showed that n-hexane clove extract had the largest inhibition zone diameter,followed by bitter kola extract and lastly tobacco extract.The antibiotic sensitivity test credited ciprofloxacin the best because it exhibited broad spectrum of action.Conclusions:Since the n-hexane extract of clove seeds demonstrated preferential growth-inhibitory activity against the causal cariogenic pathogens(S.mutans) in dental caries,we therefore,report here that clove extract be henceforth considered as a potential ingredient in toothpaste preparation.

Surface modified solid lipid microparticles based on homolipids and Softisan 142:preliminary characterization

ObjectiveTo preliminarily investigate three different lipid matrices consisting of two natural homolipids from Capra hircus (goat fat) and Bovine Spp. (tallow fat) and one semi-synthetic lipid (Softisan? 142) separately structured with Phospholipon? 90G (P90G) as potential delivery systems for poorly water soluble drugs.MethodsThe structured lipid matrices were characterized by differential scanning calorimetry (DSC) and employed to prepare solid lipid microparticles (SLMs) by the melt homogenization method using gradient concentrations of polysorbate 80 and at different emulsification times of 2, 5 and 10 min using a Silverson mixer. The SLMs were analyzed for morphology and particle size, thermal properties, stability studies and determination of injectability.ResultsThe results showed that SLM production was optimum at 5 % of lipid matrices, 1.5 % of polysorbate 80 and emulsification time of 5 min. Increase in polysorbate 80 concentrations decreased the particle size of the SLMs. The SLMs were well formed, spherical, smooth and non-porous with particle sizes in the ranges of (13.90 ± 2.10) μm - (0.09 ± 0.01) μm for SLMs produced from the structured - tallow fat; (13.40 ± 1.30) μm - (0.10 ± 0.01) μm for the structured - goat fat and (13.40±2.00) μm - (2.10± 1.00)μm for the structured Softisan? 142 lipid matrices. DSC traces showed that Softisan? 142 was the most crystalline of all three bulk matrices due to its high enthalpy (?7.962 mW/mg) while tallow fat was the least (?5.067 mW/mg) but addition of P90G to the matrices lowered their enthalpies mostly in the structured goat fat matrices. The SLMs when stored at 4-6 ° were most stable and syringeable with 27 G needle.ConclusionsThis suggests that structured goat fat matrices with the enthalpy of ?2.813 mW/mg will mostly favour drug loading of some poorly soluble drugs more than tallow fat (?4.892 mW/mg) and Softisan? 142 (?5.501 mW/mg).