Bacterial keratitis is a common ophthalmic disease. In certain cases of pseudomonas keratitis, the corneal perforation may occur within 24-48 hours of the onset. Soa suitable, massive antibiotic should be promptly used in these cases. Intensive topical therapy with fortified aminoglycoside antibiotics is a current mainstay in the treatment of bacterial keratitis because insufficient antibiotic concentrations may not inhibit bacterial growth. In 1985, Glasser and associates reported the effect of longer dosing intervals on corneal gentamicin levels with using topical fortified gentamicin solutions in rabbits. We compared peak and trough antibiotic levels achieved in the rabbit cornea by various topical administrations of tobramycin which was prepared in a concentration of 13.6mg/ml by fortifying commercially available ophthalmic tobramycin solution with injectable drug. A loading dose consists of one drop given every minute for five minutes. 1. Eyes receiving one drop every hour(Group 1) and three drops every two hours(Group 5) showed little conjunctival hyperemia. Eyes given one drop every 30 minutes(Group 2) developed minimal inflammatory responses, as did eyes given a single loading dose followed by one drop each hour(Group 4). The moderate inflammatory response occurred in eyes receiving sequential loading doses(Group 3). Abnormalities in the cornea and the iris were not seen in all studied groups. 2. Gentamicin peak level in sequential loading doses group(Group 3) was significantly higher than those achieved by one drop every hour(Group 1) or one drop every 30 minutes(Group 2). At two hours of gentamicin administration, sequential loading doses(Group 3) produced remarkably high concentrations: than those produced in Group 1, Group 2, or three drops every two hours(Group 5). During the first four hours, Group 3 represented high antibiotic levels than those produced in Group 1, Group 2, Group 5, or a single loading dose followed by one drop each hour(Group 4). There were no significant differences between trough levels with on drop every hour(Group 1) and three drops every two hours(Group 5).
Administration, Topical* ; Anti-Bacterial Agents ; Cornea ; Corneal Perforation ; Gentamicins ; Hyperemia ; Iris ; Keratitis ; Pseudomonas ; Rabbits* ; Tobramycin*

Endoscopy ; Gelatin ; Gentamicins ; administration & dosage ; Humans ; Paranasal Sinuses ; surgery ; Triamcinolone Acetonide ; administration & dosage ; Wound Healing ; drug effects

The histopathological alterations in the vestibule due to aminoglycosides are well defined. Although there are reports comparing the vestibulotoxic effects of the many aminoglycosides, this is the first study to compare the effects of the most commonly used aminoglycosides i.e., streptomycin, gentamicin, amikacin and netilmicin administered both transtympanically and systemically. The transtympanic and systemic administration of each aminoglycoside caused similar histopathological alterations in the vestibule. The most severe degeneration in the cristae ampullaris, utriculus and sacculus was observed after streptomycine administration. The severity of the vestibular damage in terms of magnitude was in the order of streptomycine, gentamicin, amikacin, and netilmicin.
Amikacin/administration & dosage/*poisoning ; Animals ; Comparative Study ; Gentamicins/administration & dosage/*poisoning ; Guinea Pigs ; Injections, Intraperitoneal ; Netilmicin/administration & dosage/*poisoning ; Streptomycin/administration & dosage/*poisoning ; Tympanic Membrane ; Vestibule/*drug effects

It has been one of important issues in nanomedicine research field to prepare drug-loaded nanoparticles. Optimization of the preparation parameters plays a key role in obtaining drug-loaded nanoparticles with homogeneous particle size and controlled drug release property. In this paper, gentamicin-loaded PLLA nanoparticles was prepared by means of double emulsion and solvent evaporation technique. Statistical software SPSS was employed to deal with the orthogonal design for optimizing the parameters of the formulation. The in vitro release of gentamicin from nanoparticles was determined by ultra-violet spectroscopy. Analysis of the experimental data based on orthogonal design demonstrated that the concentration of PLLA solution and the molecular weight of PLLA had significant influence on the size of nanoparticles, and the ratio of oil phase to water phase exhibited determined role in the gentamicin release property. Gentamicin-loaded PLLA nanoparticles prepared with the optimized parameters showed homogeneous particle size of 277 nm and sustained release property, which displayed a promising potential of clinical applications.
Delayed-Action Preparations ; chemical synthesis ; Drug Carriers ; Gentamicins ; administration & dosage ; pharmacokinetics ; Lactic Acid ; administration & dosage ; pharmacokinetics ; Nanoparticles ; administration & dosage ; chemistry ; Polyesters ; Polymers ; administration & dosage ; pharmacokinetics

PURPOSE: Community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) infections are increasing. Although gentamicin (GEN) is usually susceptible against CA-MRSA, GEN is rarely considered for treatment as monotherapy. We employed an in vitro pharmacodynamic model (IVPDM) to compare efficacies of GEN against CA-MRSA with two dosing regimens [thrice-daily (TD), once-daily (OD)]. MATERIALS AND METHODS: Using two strains of CA-MRSA, we adopted IVPDM comprised of two-compartments with a surface-to-volume ratio of 5.34 cm-1. GEN regimens were simulated with human pharmacokinetic data of TD and OD. Experiments were performed over 48 hours in triplicate for each strain and dosing regimen. RESULTS: MICs of GEN for YSSA1 and YSSA15 were 1 and 2 mg/L, respectively. In OD, indices of peak/MIC were > 8.6 at least, in contrast to < 6.4 in TD. A > or = 3-log10 reduction in CFU/mL was demonstrated prior to 4 hours in TD and OD, and continued until 8 hours for both strains. However, reductions in the colony counts at 24 and 48 hours were significantly larger for OD compared to TD in both strains (p < 0.001). During TD, resistance developed in YSSA1 and small colony variants (SCVs) were documented in YSSA15. No resistance or SCVs were observed during OD in both strains. CONCLUSION: TD and OD showed the same killing slopes until 8 hours. After the 24 hours of experiments, OD of GEN would be advantageous not only in having more reductions in colony counts, but also suppressing the development of resistance or SCVs for 48 hours.
Anti-Bacterial Agents/*administration & dosage/pharmacokinetics/*pharmacology ; Drug Administration Schedule ; Gentamicins/*administration & dosage/pharmacokinetics/*pharmacology ; Humans ; Methicillin-Resistant Staphylococcus aureus/*drug effects ; Microbial Sensitivity Tests

The gentamicin sulfate carried calcium sulfate (GSCS) implants were fabricated by the coagulating method, and the release rate of the gentamicin tested by UV-spectrometer and the absorbing rate of the calcium sulfate carrier in vitro were studied. The release patterns of two types of GSCS were compared. The trend of daily weight loss of GSCS was found being similar to that of pure calcium sulfate, which suggested that the gentamicin part has little effect on the absorbing pattern of calcium sulfate. The release rate of gentamicin is controlled by the erosion rate of calcium sulfate, so GSCS with different amount of gentamicin has the same release patterns. The DRP value of ED is higher than that of CO during the early stage, while the DRP value of ED is lower than that of CO during the late stage. The GSCS samples were implanted into the defect mold on the radii of the rabbits to investigate the potential for the use of GSCS implants as bone fillers, and the results revealed that new bone had been induced in a great part of the defect at 14 weeks after operation.
Animals ; Anti-Bacterial Agents ; administration & dosage ; pharmacokinetics ; Bone Regeneration ; drug effects ; Calcium Sulfate ; administration & dosage ; Gentamicins ; administration & dosage ; pharmacokinetics ; Implants, Experimental ; Rabbits ; Radius Fractures ; therapy

OBJECTIVETo study the influence of intranasal medication on the structure, pathology and reversibility of the nasal mucosa to provide a basis for the feasibility of intranasal route of drug administration.

METHODSNasal drops of gentamicin were placed in the nasal cavity of rabbits for 3, 5, 7, 14 and 28 days. After that, the drops were stopped and drugs protecting the nasomucosa were used for one and three weeks. After being sacrificed over time, the nasomucosa of the rabbit was observed under optical and electron microscopes.

RESULTSDamage to the nasal mucosa appeared to different extents with prolonged use of nasal drops. Within 3 - 7 days of applying the drug, damages to the nasal mucosa gradually appeared, and after two and four weeks, were most serious. After stopping the drug, the nasal mucosa was gradually restored.

CONCLUSIONDamages of drugs to the nasal mucosa could be restored. The intranasal route of drug administration would be feasible and clinically applicable.

Administration, Intranasal ; Animals ; Anti-Bacterial Agents ; administration & dosage ; pharmacology ; Gentamicins ; administration & dosage ; pharmacology ; Microscopy, Electron ; Nasal Mucosa ; drug effects ; pathology ; ultrastructure ; Rabbits ; Time Factors ; Wound Healing

OBJECTIVETo investigate uptake and accumulation of gentamicin by cells in the guinea pig inner ear after intratympanic injection using a fluorescent probe--gentamicin-Texas-red conjunction (GTTR).

METHODSAdult guinea pigs (n = 80) were administered a single dose of GTrR to the middle ear cavity through the intact membrane and survived for 12 h, 24 h, 48 h, 3 d, 4 d, 7 d, 14 d and 28 d. The distribution of GTTR in the cochlear and vestibular cells was observed after staining with phalloidin-alexa-488. Texas Red and DMSO were injected into the tympanum as control.

RESULTSDiffuse staining of gentamicin in the labyrinth was observed initially after local drug administration. At later time point the outer hair cells and sensory cells of vestibular organ were staining more densely than the support cells in the inner ear. The peak level of fluorescent density was reached 3 days after local injection. The GTTR was observed in the infracuticular zone.

CONCLUSIONSGTTR was a potential fluorescent probe to investigate the pharmacokinetics and mechanisms of gentamicin accumulation in local application.

Animals ; Anti-Bacterial Agents ; administration & dosage ; pharmacokinetics ; toxicity ; Ear, Inner ; metabolism ; Fluorescent Dyes ; Gentamicins ; administration & dosage ; pharmacokinetics ; toxicity ; Guinea Pigs ; Hair Cells, Auditory ; metabolism

OBJECTIVETo observe the therapeutic effect of local antibiotic injection into the female prostate on female urethral syndrome (FUS), and search for an effective treatment for this disease.

METHODSThis study included 163 FUS patients treated in the out-patient department between July 2009 and December 2010. According to the visiting order, the patients were randomly assigned to Groups A (n = 58), B (n = 55) and C (n = 50). All underwent routine treatment. Inaddition Group A received local injection of 2 ml of 80 000 U gentamycin + 2 ml of lidocaine, and Group B 2 ml of normal saline + 2 ml of lidocaine, both injected into the distal segment of the urethral back wall where the female prostate is located, twice a week for 3 weeks. The therapeutic effects were evaluated according to the changes of the patients' independent symptom scores at 2 and 4 weeks after the treatment. Disappearance of the symptoms was considered as "curative" , > 1/2 reduction in the symptom score as "obviously effective", 1/2 - > 1/4 reduction in the symptom score as "effective", and < 1/4 reduction or increase in the symptom score as "ineffective".

RESULTSAt 2 weeks after the treatment, the total effectiveness rate was significantly higher in Group A (77.5%) than in B (67.3%) and C (68.0%) (P < 0.05), but with no statistically significant difference between B and C (P > 0.05). At 4 weeks, the total effectiveness rate of Group A was slightly decreased, but still remarkably higher than that of group B or C (P < 0.05).

CONCLUSIONLocal injection of gentamycin into the female prostate is effective for the treatment of female urethral syndrome.

Administration, Topical ; Adult ; Aged ; Aged, 80 and over ; Female ; Gentamicins ; administration & dosage ; therapeutic use ; Humans ; Injections ; Middle Aged ; Prospective Studies ; Treatment Outcome ; Urethral Diseases ; drug therapy ; Young Adult

OBJECTIVETo explore the therapeutic efficacy of patients with ulcerative colitis (UC) treated by retention enema and per-colonoscopic spraying of Zhikang Compound Liquid (ZKCL).

METHODSEighty-six patients with UC were divided into two groups. The 52 patients in the treated group were treated for 4 courses of retention enema, the drug for enema used in the 1st course was ZKCL-A (consisted of normal saline, Zhikang capsule, gentamycin and dexamethasone) and smecta, in the 2nd course ZKCL-A alone, in the 3rd and 4th course, ZKCL-B (with the same contents of ZKCL-A but without dexamethasone), the enema was carried out once a day in the evening, 15 days as one course. Besides, local spraying of ZKCL-A and smecta were given once by colonoscopy before the 1st and 3rd course. The 34 patients in the control group were treated by salicylazosulfapyridine orally.

RESULTSIn the treated group, 32 patients got complete remitted, 15 were treated effectively, 5 ineffectively, the total effective rate being 90.38% while the corresponding number in the control group were 8, 14, 12, and 64.71%, respectively. Significant difference was seen when compared with the therapeutic effects of the two groups. CONCLUSION Good efficacy was got in treating patients with UC by retention enema and per-colonoscopic spraying with ZKCL.

Administration, Rectal ; Adult ; Aged ; Aged, 80 and over ; Colitis, Ulcerative ; drug therapy ; pathology ; Colonoscopy ; Dexamethasone ; administration & dosage ; Drug Therapy, Combination ; Drugs, Chinese Herbal ; administration & dosage ; Female ; Gentamicins ; administration & dosage ; Humans ; Male ; Middle Aged ; Phytotherapy