[Particulate contamination of amino acid solutions for parenteral use]. / Studio sulla contaminazione particellare di soluzioni di aminoacidi per uso parenterale.

Three industrial batches of a 10% (w/v) amino acid solution have been checked for particulate contamination. The batches differed in preparative technology and/or type of additives. In particular, one batch was prepared under nitrogen, filled under vacuum and with the addition of sodium metabisulfite and cysteine. The other two batches were simply prepared under nitrogen and differed in the presence or not of cysteine and sodium metabisulfite. Accelerated stability tests were performed (40, 50, e 60 degrees C) and controls were effected both at room (25 degrees C) and refrigerator (6 degrees C) temperature. The results show that the preparation under nitrogen and the presence of cysteine result in an improved chemical stability and allow the particulate contamination level to be maintained within the limits of the Italian Pharmacopoeia. In particular, the batch prepared under nitrogen and filled under vacuum is characterized by a particulate contamination level which remains within the more restrictive limits of the British Pharmacopoeia for the entire period of the stability studies. Moreover, the particulate contamination control performed at 6 degrees C has proved to be a useful predictive tool with regards to batch quality evaluation.

Synthesis of some derivatives of 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(piperazin-1-yl)-3-quino linecarbo xylic acid (norfloxacin) as potential antibacterial agents.

Twelve new fluoroquinolones, structurally related to norfloxacin, have been synthesized in order to investigate the effect of substituents at the secondary nitrogen of the piperazine ring on antimicrobial activity. The new substances (carbamates, isoureas, guanidines, ureas and cyanamides) tested on a variety of gram-positive and gram-negative organisms showed lower activity than the model compound.

Metabolic pathways of the contragestational agent, 3-(2-ethylphenyl)-5-(3-methoxyphenyl)-1H-1,2,4-triazole (DL 111-IT), in the rat.

The metabolic pathways of the non-hormonal anti-fertility agent 3-(2-ethylphenyl)-5-(3-methoxyphenyl)-1H-1,2,4-triazole (DL 111-IT) were studied in rats given the 14C-labelled compound intramuscularly. The diaryltriazole, once absorbed, was metabolized rapidly by three phase I reactions: (a) hydroxylation at the C-4 of the methoxyphenyl ring, (b) hydroxylation at the alpha-C of the ethyl chain, and (c) demethylation of the methoxyl function. Seven free metabolites and three conjugates have been isolated and characterized by u.v., i.r., n.m.r. and mass spectroscopy. The products of the first step of metabolism of the diaryltriazole were tested for their pregnancy-terminating activity in the rat. They were only 5-9% as effective as the parent compound, indicating that the unchanged drug is the active molecule.

[Hexahydroimidazo[1,5-a]-pyrazine. II. Synthesis of 7-phenyl-1,5,6,7,8,8a-hexahydroimidazo[,5-a]pyrazine-3(2H)-one and derivatives]. / Esaidroimidazo[1,5-a]pirazine. Nota II. Sintesi del 7-fenil-1,5,6,7,8,8a-esaidroimidazo[1,5-a]pirazin-3(2H)-one e derivati.

The synthesis and activity on the central nervous system of a series of 2-aryl or 2-alkyl-7-phenylhexahydroimidazo[1,5-a] pyrazin-3(2H)-ones (II a-f) are reported. The intermediate 3-carbomethoxy-1-phenylpiperazine (X) was prepared in six steps from aniline and methyl-2-chloroacrylate. Compared with that of derivatives of Zetidoline, the depressant activity of (II a-f) is markedly reduced.

A new class of nonhormonal pregnancy-terminating agents. Synthesis and contragestational activity of 3,5-diaryl-s-triazoles.

A series of 3,5-diaryl-s-triazoles were synthesized and evaluated as postimplantation contragestational agents. The introduction of various substituents (e.g., an o-alkyl chain on one phenyl and a m-alkoxy group on the other) was found to increase the potency. Several compounds with very high pregnancy-terminating activity in both hamsters and rats were obtained. One of these, 3-(2-ethylphenyl)-5-(3-methoxyphenyl)-s-triazole, DL 111 (36), was selected for detailed evaluation in various animal species. A synthetic scheme for the preparation of these compounds and preliminary structure-activity relationships are presented.

Pharmacokinetics-activity relationships of a new non-hormonal antifertility agent: 3-(2-ethylphenyl)-5-(3-methoxyphenyl)-1H-1, 2,4-triazole, in the rat and the hamster.

The pharmacokinetic profiles of a new non-hormonal anti-fertility agent, DL 111-IT, were studied in rats and hamsters given the 14C labelled compound parenterally dissolved in aqueous or oily vehicles. In both species, DL 111-It was rapidly metabolized and excreted when given intravenously or subcutaneously in aqueous vehicles (half-lives = 15-45 min.), whereas the kinetics were prolonged when it was administered in oily formulations (half-lives = 7-10 h). Binding studies revealed a high affinity of DL 111-IT for rat serum albumin (Ka = 6 X 10(5) 1/mole). The radioactivity concentrations in different tissues of pregnant rats appeared to be uniform with the excretory organs and lungs being the main target tissues. At the site of action, the utero-placental complex, the levels of total 14C were comparable to those in plasma, whereas the concentration of unchanged DL 111-IT was higher and remained so for a longer time. A comparison between the kinetic profiles and the activity data after single or multiple dose administration in different formulations, clearly indicates a close relationship between activity and plasma and tissue (utero-embryo placental complex) levels of DL 111-IT, and also makes clear the influence of the formulation and of the treatment schedule on the anti-fertility activity of the compound.

Synthesis and pregnancy terminating activity of 2-arylimidazo [2,1-a]isoquinolines and isoindoles.

A series of 2-arylimidazo[2,1-a]isoquinolines (1-21), some 5,6-dihydro derivatives (22-28) and 2-phenyl-5H-imidazol[2,1]isoindole (29) were synthesized and tested for the pregnancy terminating activity in hamsters and rats. An efficient preparation of 2-arylimidazo[2,1-a]isoquinolines was devised. The isoquinolines having a 4-chlorophenyl (8), 4-bromophenyl (9), or a biphenylyl group (12) in the 2-position were the most potent compounds after subcutaneous administration. Compound 12 also showed good oral activity. The data obtained with the title compounds are compared with those of the corresponding triazolo [5,1-1]isoquinolines and isoindoles. The structure-activity relationships are discussed.

DL 111, a new non-hormonal antifertility agent: contragestational and kinetic profile in baboons.

It was previously shown that 3-(2-ethylphenyl)-5-(3-methoxyphenyl)-1H-1,2,4 triazole (DL 111) given parenterally in single or multiple doses during the early stage of embryonal development terminates pregnancy in the mouse, the hamster, the rat, the rabbit and the dog. In the present work, the studies have been extended to the baboon. In this sub-human primate, single and/or multiple intramuscular injections of the compound terminated pregnancy when given between day 34 and 54 of gestation. The effectiveness of DL 111 was greater when earlier in gestation and the optimal mode of treatment appears to be a multiple one. DL 111 appears to act by a direct action on the conceptus, with consequent suppression of the endocrine function of the placenta, progesterone withdrawal and abortion. In all the baboons that aborted, the menstrual cycles resumed within a reasonable length of time and subsequent cycles were regular. All the animals that did not abort have given birth to normal and health term infants. Fertility appears to be unimpaired and the progeny resulting form these pregnancies did not show any abnormalities. No significant drug-related side-effects or alterations in plasma enzymes or haematological parameters were observed. Pharmacokinetic and activity relationships strongly suggest that sustained exposure of the conceptus to the drug action is indispensable for optimizing the pregnancy-terminating effect.

Species differences in the disposition and metabolism of 1-methyl-3-(3-pyridyl)-5-(2-hydroxy-methylphenyl)-1H-1,2,4-triazole, a potential sedative-hypnotic compound.

1. Disposition and metabolism of 1-methyl-3-(3-pyridyl)-5-(2-hydroxy-methylphenyl)-1H-1,2,4-triazole, a new sedative-hypnotic, were studied in rats (i.v. and p.o.), cats (i.v.) and human volunteers (p.o.) with 14C-labelled drug. 2. In rat and man, the compound is well absorbed, extensively metabolized, and excreted mostly through the kidney; it has short plasma half-lives, 0.6 h in rat, 0.9 h in man, and 1.9 h in cat. 3. In rat and man metabolism involves N-oxidation of the pyridine ring (Metabolite I), and in cat oxidation of the hydroxymethyl group (Metabolite II). Four other conjugated metabolites (III-VI) isolated from rat urine and bile, and from urine of cats and man, have been characterized. 4. The unchanged compound, but not its metabolites, crosses the blood-brain barrier in rat and cat. 5. The species differences in the disposition and metabolism of the compound are consistent with previous pharmacological data indicating a greater and more prolonged effect in cat.

Increased oral activity of a new class of non-hormonal pregnancy terminating agents.

A series of selected analogues of 2-(3-ethoxyphenyl)-5,6-dihydro-s-triazole [5, 1-a] isoquinoline (DL 204-IT) modified at the three sites of metabolism of the DL 204-IT molecule, were studied for their anti-fertility activity and absorption (in situ and in vivo) following oral administration to the hamster. All test-compounds were rather well absorbed, nevertheless, the ratios between the oral and subcutaneous pregnancy termination activity ranged between 3 and 722, suggesting a marked influence of metabolic first-pass. One of these new anti-fertility agents, 2-(1, 1'-biphenyl-4-yl)-s-triazole [5, 1-a]-isoquinoline (L 14105), showed an interesting oral activity (ED50: 0.2 mg/kg/d), 300 times greater than that of the parent compound DL 204-IT.

A new class of non-hormonal contragestational agents: pharmacodynamic-pharmacokinetic relationships.

PIP: As part of a research program designed to find new potential antifertility agents, new non-hormonal, non-prostaglandin-like compounds belonging to the class of 2-phenyl-triazole (5,1-a) isoindoles Ia and the corresponding dehydro-isoquinolines Ib were identified in the laboratories of the Departments of Pharmacokinetics, Organic Chemsitry, and Endocrinology (Gruppo Lepetit, Milan, Italy). These new structures were shown to be effective at nontoxic doses in several animal species as post-implantation, early pregnancy termination agents. Starting from these leader compounds, studies designed to clarify simultaneously both their spectrum of activity and the structure-activity relationships were undertaken. Following this initial explorative phase, keeping in mind that an antifertility agent must be highly effective over a period of time sufficiently long to block a dynamic process such as pregnancy, selected compounds were studied in depth in order to determine the relationships between their bioavailability and their effectiveness. This manuscript reviews the multidisciplinary research which led to the selection of the 1st generation compounds that have not only the very high potencies but also the diverse kinetic characteristics to make them suitable for potential use in animals and in humans. In the development of these new contragestational agents, it was apparent early that the achievement of the biological effect would be strictly dependent upon prolonged availability. Thus, in the primary screening, the period of treatment in pregnancy (most effective time), the route (subcutaneous), and the schedule of treatment (multiple daily doses) chosen, were those least affected by kinetic and metabolic factors. Structure-activity relationships studies in 2 species with marked differences in sensitivity (rat, hamster) made it possible to ascertain the key portions of the molecules and the types of substituents that could either improve the activity or reduce the species specificity. This initial research phase led to the selection of several compounds with high pregnancy terminating activity after multiple parenteral administration. Concurrently, the contragestational activity of some of the most interesting products, possessing different physico-chemical properties, was measured at various stages of gestation, when given in different schedules, by different routes, and in different vehicles. The main evidence that emerged, when related to the pharmacokinetic profiles and the phyisico-chemical properties of each molecule, indicated the following kinetic-activity relationships: the effectiveness of the compounds was shown to be dependent on time of gestation, route, vehicle, and schedule of administration; the ideal time course of the compounds at the site of action requires sustained kinetics, while short exposures even to high concentrations are not very effective in interrupting the embryonic development; the maximal effectiveness can be obtained when the exposure of the products of conception to the drug action lasts for whole length of time needed to arrest pregnancy; the period of efficacy during pregnancy can be lengthened by administering long lasting compounds before the period of maximal effectiveness; and the loss of contragestational activity observed when the compounds are given orally is mainly due to a metabolic first-pass.^ieng

The synthesis of 2 14C-labelled 2-(3-alkoxyphenyl)-5,6-dihydro-5-trazolo[5, 1-a] isoquinoline compounds, novel antifertility agents.

PIP: 2 new compounds, L-10503, 2-(3-methoxyphenyl)-5,6-dihydro-s-triazolo [5,1-a] isoquinoline and DL-204 IT, 2-(3-ethoxyphenyl)-5,6-dihydro-s-triazolo [5,1-a] isoquinoline have been developed in the Lepetit Research Laboratories in Milan, Italy. These compounds have been tested in monkeys and rats and have been shown to terminate pregnancy after a single intramuscular injection. Pharmocokinetical, metabolic, and placental absorption studies of these compounds required synthesis of 14 C labelled forms for both. This article describes in details the laboratory procedures to obtain synthesis of these compounds.^ieng

A new non-hormonal pregnancy-terminating agent.

DL 111-IT, 3-(2-ethylphenyl)-5-(3-methoxyphenyl)-1H-1,2,4 triazole, a compound belonging to a new class of non-hormonal antifertility agents, when given subcutaneously, intramuscularly, intravaginally or orally terminates pregnancy in the rat, the mouse, the hamster and the dog. Time-course and dose-activity studies indicate that its effectiveness is dependent on dose, vehicle, route and time of pregnancy. DL 111-IT has no pre-implantation activity. The most effective time for treatment is the early post-implantation period. The compound has an antifertility effect through a slow and continuing action that results in the degeneration and subsequent resorption or expulsion of conceptuses. As a result, there must be sustained availability of active principle to arrest the pregnancy. Administered parenterally in a proper vehicle (oily) and with a suitable schedule of treatment (x 2-5 days), it demonstrates a very high pregnancy terminating activity (ED50: 0.04-0.7 mg/kg/day). Multiple intravaginal and oral administrations are also effective but the daily doses required are 10-20 and 40-100 times higher than the parenteral ones. Studies of the mechanism of action indicate that the site of action is the utero-placental complex. In fact, in pregnant rats, mice, hamsters and dogs, both plasma progesterone levels and the ineffectiveness of progesterone therapy rule out luteolysis as a basis for the activity. Moreover in hypophysectomized, ovariectomized animals whose pregnancies were maintained with proper hormonal treatments, DL 111-IT terminates pregnancy and adrenalectomy does not prevent its effect, which suggests that pituitary, ovaries and adrenals are not required for the antifertility action.

[Synthesis of 2-aminoisoindolin-1-ones with or without 6-substituents]. / Sintesi di 2-aminoisoindolin-1-oni-5 e/o 6-sostituiti

The synthesis of 5- and 6-chloro, 5- and 6-methoxy, 5,6-dimethoxy, 6-amino and 6-nitro-2-aminoisoindolin-1-ones (III b...h), starting from the substituted phthalides (Vb...g), are reported. Chloro and methoxy-derivatives (III b...f) have been prepared by reduction of phthalazin-1-(2H)-ones (Ib...f) with zinc and acids under controlled conditions to afford the 3,4-dihydrocompounds (II), that have been rearranged to (III b...f) with hydrazine hydrate or hydrochloric acid (Scheme 3). The synthesis of 6-nitro and 6-amino-derivatives (III g,h) have been respectively accomplished by hydrolysis and hydrogenolysis of 6-nitro-2-benzylidenaminoisoindolin-1-one (IV g), prepared by chlorination and ring closure with sodium carbonate of benzylidenhydrazide of 5-nitro-2-hydroxymethyl-benzoic acid (Scheme 2).

[Hexahydroimidazo[1,5-a]pyrazine. I. Synthesis of 7-methyl-1,5,6,7,8a-hexahydroimidazo[1,5-a]pyrazin-3(2H)-one and derivatives]. / Esaidroimidazo[1,5-a]pirazine I - Sintesi del 7-metil-1,5,6,7,8,8a-esaidroimidazo[1,5-a]pirazin-3(2H)-one e derivati

The synthesis and pharmacological activity of a series of 2-aryl or alkyl substituted 7-methyl-1,5,6,7,8,8a-hexahydroimidaso[1,5-a]pyrazin-3(2H)-ones, are reported. The 2-aryl derivatives (VI) have been prepared by reaction of 3-(arylaminomethyl)-1-methylpiperazines (IV) have been prepared by reaction of 3-(arylaminomethyl)-1-methylpiperazines (IV) with N,N'-carbonyldiimidazole. Reaction of various anilines with 3-carbomethoxy-1-methylpiperazine (II) and subsequent reduction of the amides (III) afforded the bases (IV). The synthesis of the unsubstituted compound (XII) has been accomplished either by cyclization with sodium methoxide of methyl (1-me-thylpiperazin-3-yl)methylcarbamate (XI) or by reaction of 3-aminomethyl-1-methylpiperazine (XV) with N,N'-carbonyldiimidazole. Reduction of 1-benzyl-2-cyano-4-methylpiperazine (VII) followed by reaction with methyl chloroformate and debenzylation afforded the urethane (XI). The 2-alkyl and 2-alkenyl derivatives (XIII) have been prepared by alkylation of the sodium salt of (XII) in DMF. The compounds of these series have been tested for antiinflammatory, coronary dilator and C.N.S. depressant activities.