tetracycline and stearic-acid

Twelve men with louse-borne relapsing fever were treated with single doses of procaine penicillin plus aluminum monostearate (PAM) intramuscularly or of tetracycline intravenously. All patients experienced a definite Jarisch-Herxheimer-like reaction. Fever and spirochetemia were significantly prolonged and peak temperature was lower and occurred later in the PAM-treated group. Peak pulmonary ventilation, metabolic rate, and arterial PO2 were significantly higher in the tetracycline-treated group. Circulatory changes were similar in the two groups but were prolonged in the PAM-treated patients. Thus, tetracycline is recommended for treatment because it is more rapidly effective in eliminating Borrelia spirochetes and produces a reaction no more stressful physiologically than the one after PAM. There was no evidence of complement activation, and there was no change in immunoglobulin levels throughout the reaction. Immune complexes were detected in serum of five patients before treatment, but in fewer patients at the peak of the reaction and subsequently.

Topics: Adult; Aluminum; Antigen-Antibody Complex; Drug Combinations; Humans; Insect Vectors; Male; Penicillin G Procaine; Phthiraptera; Relapsing Fever; Respiration; Stearic Acids; Tetracycline

Solid lipid nanoparticles (SLNs) produced by conventional microemulsion techniques using thermal heat have specific limitations (e.g. high polydispersity, instability and low encapsulation). Replacing thermal heat with microwave heat may produce SLNs which overcome some of these limitations.. Stearic acid-based SLNs prepared with Tween® 20 as the emulsifier were chosen as the optimum formulation to encapsulate and potentially deliver the antibacterial drug tetracycline. All formulations were characterized for their particle size, zeta potential, encapsulation efficiency, loading capacity, thermal and X-ray diffraction analyses. Short-term stability and in vitro drug studies were also performed.. Microwave heating helps to overcome several disadvantages associated with thermal heating (nonuniform, inefficient and slow) and results in improved particle characteristics. There is thus the potential for new opportunities in the development of colloidal carriers. The particle sizes of microwave-produced SLNs were in the desired nanometer range (200-250 nm) with both lower size and lower polydispersity than the conventional SLNs. We take this as an indication of improved stability; however zeta potential measurements were not different, indicating similar stability. True stability testing (visual observation with time) did show that the microwave-induced SLNs were found to be more stable, particularly when refrigerated. The microwave-produced SLNs also demonstrated improved encapsulation efficiency and loading capacity. Thermal and diffraction analysis confirmed a lowered crystallinity of stearic acid with successful incorporation of tetracycline into the SLNs. In vitro release studies indicated that, after an initial burst release, SLNs could provide prolonged release of tetracycline. The presence of tetracycline and non-toxicity of carriers towards microbes was confirmed by antimicrobial susceptibility tests.

Topics: Anti-Bacterial Agents; Drug Carriers; Emulsions; Escherichia coli; Escherichia coli Infections; Humans; Microwaves; Nanoparticles; Polysorbates; Staphylococcal Infections; Staphylococcus aureus; Stearic Acids; Tetracycline

Stearic acid, a saturated fatty acid was isolated from the microalga Spirulina platensis. Some novel stearic acid analogues having 1,3,4-oxadiazole, 1,2,4-triazole and 1,2,4-triazolo-[3,4-b]-1,3,4-thiadiazole are synthesized and characterized by IR, NMR and mass spectral analysis. All the synthesized compounds were screened for antimicrobial activity by using cup plate method. The synthesized compounds have been further screened for their antidepressant activity in swiss albino mice by forced swim test (FST), midbrain dopamine has been estimated and quantified. All the compounds showed good antimicrobial activity and compound 6 showed significant antidepressant activity.

Topics: Animals; Anti-Infective Agents; Antidepressive Agents; Bacteria; Behavior, Animal; Chemistry Techniques, Synthetic; Dopamine; Fungi; Male; Mice; Stearic Acids; Swimming

Topics: Esters; Intestinal Absorption; Isoniazid; Pharmacology; Rats; Research; Salicylic Acid; Stearic Acids; Sucrose; Sulfanilamide; Sulfanilamides; Surface-Active Agents; Tetracycline