Comparative bioavailability of three brands of ampicillin

The relative biological availability (bioavailability) of three brands of ampicillin trihydrate capsules marketed in Canada was studied by means of a crossover experimental design and was evaluated by analysis of variance. After administration of a single oral dose (500 mg.) to volunteer subjects, the mean peak ampicillin serum concentration and the area under the time ampicillin serum concentration curve (AUC) were higher for one of the products than for the other two. A second study utilizing the same experimental design revealed no differences in these parameters when different production lots of the more available product were compared. Product bioavailability was not related to the in vitro dissolution time of the capsules. The experimental design and methods of statistical analysis are discussed.     

Relative bioavailability of ethinyl estradiol from two different oral contraceptive formulations after single oral administration to 18 women in an intraindividual cross-over design

Two low-dose oral contraceptives, both containing the same dose of ethinyl estradiol (EE2) but different progestins (gestodene and desogestrel, respectively), were compared with respect to the relative bioavailability of EE2. After single-dose administration of both formulations to 18 women in an intraindividual cross-over design, there was no difference in the target variables for EE2 (Cmax, tmax and AUC). With respect to EE2, both formulations were bioequivalent. The observation of others, reporting higher EE2 levels in the serum of women taking the gestodene-containing formulation as compared to those taking the desogestrel-containing formulation, was not confirmed.     

Relative bioavailability of scopolamine dosage forms and interaction with dextroamphetamine

The NASA Reduced Gravity Office (RGO) uses scopolamine (SCOP) alone and in combination with dextoamphetamine (DEX) to treat motion sickness symptoms during DC-9 parabolic flights. The medications are sometimes dispensed as custom dosage forms in gelatin capsules for convenience. Reports of treatment failure during flights by the flight surgeons suggest that these formulations may be less efficacious for the treatment of motion sickness due to unreliable and inadequate bioavailability. We estimated bioavailability of four different oral formulations used by the NASA RGO physicians for the treatment of motion sickness.     

Relative bioavailability and bioequivalence of the antimycotics ketoconazole and fluconazole]

Pharmacokinetics and bioavailability of the antimycotics ketoconazole FPO and fluconazole (Russia) and the analogous drugs nizoral (Belgium) and diflucan (France) were comparatively studied on animals and in clinical trials. The pharmacokinetic parameters of the drugs were determined and their bioequivalence was shown (90-110%) that is evident of their therapeutic equality.     

Sublethal responses of the German cockroach to vapors of commercial pesticide formulations

The effects of vapors of four commercial propoxur formulations and their solvent systems (blanks) on dispersal of German cockroaches, Blattella germanica (L.), of a laboratory susceptible and two propoxur-resistant field strains were studied. Little or no dispersal occurred in experiments with water-based formulations (emulsifiable concentrate and wettable powder). Rapid dispersal occurred in experiments with aerosol and propoxur-in-oil formulations and their blanks. The order from most rapid to slowest dispersal was as follows: propoxur-in-oil, aerosol, aerosol blank and oil blank. Each strain differed from the others in response to at least one of the test materials.

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Résumé L'étude a porté sur les effets des vapeurs de quatre formules commerciales de propoxure et de leurs solvants sur la dispersion d'une souche sensible de laboratoire et de deux souches résistantes de la nature de B. germanica L.. Avec des solutions aqueuses, concentré émulsifiable ou poudre mouillable, la dispersion est faible ou nulle. Une dispersion rapide est obtenue avec des aérosols ou des formules de propoxure en solution dans l'huile ou avec ces solvants seuls. Le classement, du dispersant le plus rapide au plus lent, est le suivant: Propoxure dans l'huile, aérosol, solvant d'aérosol, solvant de solution huileuse. Chaque souche diffère des autres pour au moins une réaction à l'une des substances testées.

     

Scale-up effects on dissolution and bioavailability of propranolol hydrochloride and metoprolol tartrate tablet formulations

This study evaluated the effects of batch size on the in vitro dissolution and the in vivo bioavailability of immediate release formulations of propranolol hydrochloride and metoprolol tartrate. The formulations were manufactured as small and large batches (6 kg and 60 kg for propranolol; 14 kg and 66 kg for metoprolol), and dissolution was performed using USP Apparatus I at 100 rpm and pH 1.2. Two panels of 14 subjects each were randomly assigned to receive the small and large batches of either propranolol or metoprolol in an open randomized single-dose study. Blood samples were collected over a 24-hour (propranolol) or 18-hour (metoprolol) period and analyzed by validated methods. As determined by thef ₂ metric (similarity factor), the dissolution of the small and large batches of propranolol and metoprolol was similar. The mean C_max and AUC_inf for the small batch of propranolol were 79.0 μ g/L and 536 μ g/L/hr and for the large batch they were 83.5 μ g/L and 575 μ g/L/hr. C_max and AUC_inf for the small batch of metoprolol were found to be 95.5 μ g/L and 507 μ g/L/hr and for the large batch, 95.1 μ g/L and 495 μ g/L/hr. The 90% confidence intervals for the small and large batches were within the 80% to 120% range for InC_max, and InAUC_inf for both the propranolol and metoprolol formulations. These results suggest that the scale-up process does not significantly affect the bioavailability of highly soluble, highly permeable drugs and in vitro dissolution tests may be useful in predicting in vivo behavior.     

Fungicidal activity and chemical constitution: XIII.* Active components of commercial formulations containing dinocap

Six isomers, isolated from the mixture of dinitrophenols obtained by the hydrolysis of commercial formulations containing dinocap, were tested in the greenhouse against apple mildew caused by Podosphaera leucotricha. The two most active compounds were 4-(Ié-ethylhexyl)- and 4-(Ié-propylpentyl)-2,6-dinitrophenols, which appear to account for most of the antimildew activity of the mixture. The crotonate of the latter phenol was considerably more effective than dinocap itself, but both crotonates were less effective than the corresponding free phenols. Little evidence of synergism between two ethylhexyldinitrophenols was obtained.     

Chemical and toxic evaluation of a biological treatment for olive-oil mill wastewater using commercial microbial formulations

Olive-oil-mill wastewater (OMW) has significant polluting properties due to its high levels of chemical oxygen demand (COD), biochemical oxygen demand (BOD), and phenols. In the present study, different commercial bacterial formulations were used in the biological treatment of OMW. COD and toxicity testing using primary consumers of the aquatic food chain (the rotifer Brachionus calyciflorus and the crustacean Daphnia magna) were employed to evaluate abatement of the organic load and reduction of the toxic potential. In addition, the four most active formulations were tested mixed pair-wise on the basis of their unique characteristics in order to evaluate the improvement of treatment. The effect of treatment was assessed by measuring COD removal, reduction of total phenols, and decreased toxicity. The results obtained with the mixed formulations showed that the maximum removal of the organic load was about 85%, whereas phenols were reduced by about 67%. The toxicity for rotifers decreased by 43% and for crustaceans by about 83%.     

Laboratory and field evaluation of commercial repellent formulations against mosquitoes (Diptera: Culicidae) in Queensland, Australia

Abstract  Laboratory tests of commercial repellent formulations were conducted against Anopheles farauti Laveran, Culex annulirostris Skuse, Ochlerotatus vigilax (Skuse) and Stegomyia aegypti (L.). The majority of repellent formulations tested contain N,N ,-diethyl- 3 -methylbenzamide (also known as diethyl- m -toluamide, commonly called deet). Two formulations containing picaridin (1-piperidinecarboxylate acid, 2-(2-hydroxyethyl)-1-methylpropylester, also known as KBR 3023), one containing ethyl butylacetylaminopropionate (EBAP) and two formulations containing essential oils (e.g. Citronella oil) were also tested. In the laboratory tests, repellent formulations containing deet provided the best protection, and picaridin and EBAP also provided good protection. Citronella oil provided only limited protection. Two field trials to compare commercially available repellent formulations containing picaridin and deet against mosquitoes at Redcliffe, Queensland, were conducted. In the first, Autan Repel, containing 9.3% picaridin, RID, containing 10% deet, and Bushman Ultra, containing 80% deet in a gel, were compared. In the second, Autan Repel Army 20, containing 19.2% picaridin, OFF! Skintastic, containing 7% deet, and Aerogard, containing 12% deet, were compared. The predominant mosquito in both tests was Cx. annulirostris . Bushman provided >95% protection against all mosquitoes for at least 8 h when tests ceased. The other deet repellents also provided good protection against mosquitoes, with RID providing 5 h, Skintastic 4 h and Aerogard 2 h protection. The Autan repel (9.3% picaridin) provided >95% protection for 3 h, and Autan Repel Army (19.2% picaridin) provided 4 h protection. These studies have shown that commercial formulations of both deet and picaridin provide good protection against Cx. annulirostris , an important vector of arboviruses in Australia.     

Enzyme immunoassay of ampicillin in milk

An indirect immunoassay for quantitative determination of ampicillin (range, 10-1000 ng/ml) in buffer or milk has been developed. Polyclonal antibodies were obtained against ampicillin conjugated with bovine serum albumin; the conjugate was synthesized by direct condensation using carbodiimide. The antibodies were specific for ampicillin and exhibited low cross-reactivity to other penicillins (azlocillin, 17%; penicillin G, 10%; piperacillin, 5%; and carbenicillin, 4%). Matrix effects were minimized by combining the use of a casein-supplemented buffer (content of casein, 1%) with sample dilution. The threshold of ampicillin detection in milk (diluted tenfold) was equal to 5.0 ng/ml (which corresponded to 50 ng/ml of the original sample).