Investigation of moricizine hydrochloride polymorphs.

The antiarrhythmic agent moricizine hydrochloride exhibits a single melting-decomposition endotherm peak at temperatures ranging from 209 to 214.5 degrees C (Form I) when recrystallized from polar solvents, as determined by differential scanning calorimetric analysis. However, a different polymorphic form (Form II), with a differential scanning calorimetric melting-decomposition peak temperature of 190 degrees C, was generated by recrystallizing moricizine hydrochloride from nonpolar solvents.

Sustained-release oral delivery of theophylline by use of polyvinyl alcohol and polyvinyl alcohol-methyl acrylate polymers.

Crystalline polyvinyl alcohol (PVA) polymer and low-crystallinity polyvinyl alcohol-methyl acrylate copolymer (PVA-MA) were examined as sustained-release tablet excipients with theophylline as a model drug. By blending of different proportions of the crystalline polymer and the low-crystallinity copolymer, it was possible to affect the release characteristics of the tablets. Tablets made with crystalline PVA provided instant release of theophylline in vitro.

Degradation kinetics and mechanisms of moricizine hydrochloride in acidic medium.

The degradation kinetics of moricizine hydrochloride (1) were examined over a pH range of 0.6 to 6.0 at an ionic strength of 0.

Polyvinyl alcohol-methyl acrylate copolymers as a sustained-release oral delivery system.

Low crystalline and crystalline polyvinyl alcohol-methyl acrylate (PVA-MA) copolymers were examined, because of their excellent flow and compressibility properties, as matrices for sustained-release tablets using phenylpropanolamine hydrochloride (PPA.HCl) as a model drug. Crystallinity of the copolymer affected the release characteristics from the tablet.

Self-association and solubility behaviors of a novel anticancer agent, brequinar sodium.

To aid in the selection of appropriate excipients to formulate brequinar sodium [6-fluoro-2-(2'-fluoro-1,1'-biphenyl-4-yl)-3-methyl-4-quinolinecarboxyli c acid sodium salt; DuP 785], studies were initiated to characterize thoroughly its solubility behavior. The measured solubilities at RT (approximately 23 degrees C) agreed with the theoretical values in the pH range from 0.5 to 7.

Effects of prenatal exposure to tricyclic antidepressants on adrenergic responses in progeny.

Studies were undertaken to examine the effects on cardiovascular function in progeny of rats treated maternally with the tricyclic antidepressants, doxepin and imipramine. Doxepin was administered once daily during the first trimester (days 1-7), second trimester (days 8-14) or third trimester (days 15-21) of pregnancy, while imipramine was administered during the third trimester only. Exposure to doxepin during the first or second trimester increased infant mortality rate, while third trimester exposure to imipramine, but not doxepin, enhanced infant mortality.

Solubility and ionization characteristics of doxepin and desmethyldoxepin.

The theromdynamic pKa values for doxepin and its metabolite desmethyldoxepin were determined by the solubility method to be 8.96 and 9.75, respectively at 25 degrees.

Pharmacokinetics of sulfisoxazole compared in humans and two monogastric animal species.

The pharmacokinetic profile of sulfisoxazole was studied and compared in dogs, swine, and humans. The trial was conducted over a 72-hr period after intravenous administration and a 96-hr period after oral administration in dogs and swine. In humans, the trial was conducted over an 8-hr period after oral administration.

Dissolution behavior of commercial enteric-coated aspirin tablets.

Dissolution behavior was studied for four commercial batches of enteric-coated aspirin tablets from two companies. The USP XIX dissolution procedure was modified by including pretreatment in simulated gastric juice. The effects of five pretreatment times were studied.

beta-Cyclodextrin as an aid to peritoneal dialysis. Renal toxicity of beta-cyclodextrin in the rat.

A peritoneal dialysate containing beta-cyclodextrin has been shown to accelerate the removal of intravenously administered phenobarbital in rats. It was found that high concentrations of beta-cyclodextrin were toxic to the animals in the single exchange technique employed. The renal toxicity was estimated by measuring blood urea nitrogen values in the rats following oral and intraperitoneal administration of the cyclic amylose.

Loss of color from Jiffy tubes.

Colored, disposable applicator tubes have been said to lose color to their contents during use. Since they are used to contol the placement of a variety of accessory materials important to clinical dentistry, a selection of restorative materials and solvents was evaluated to determine which had a color-leaching potential. Neither aqueous system nor alcohol, chloroform, eugenol, xylene, or ether caused a loss of color that was clinically significant.

Effect of orange juice consumption on urinary pH.

The effect of orange juice consumption on urinary pH was studied in seven adult male subjects, each of whom served as his own control. The diet of the subjects was standardized during the work-day. The effects of two regimens of orange juice were studied: 1500 ml divided into five 300-ml portions during the day, and 300 ml once in the morning.

Evaluation of preparations of patent blue (Alphazurine 2G) dye for parenteral use.

The stability and the behavior of patent blue (Alphazurine 2G) dye in a vehicle such as lidocaine hydrochloride injection were studied with regard to medication orders which may be prepared by hospital pharmacists. The patent blue family of dyes are sulfonated diaminotriphenylmethane, vital, acid dyes which have been used as diagnostic aids in both lymphography and burn debridement. A literature review, including some toxicological information, is presented.

Extemporaneous preparation of methyldopa in two syrup vehicles.

The stability of methyldopa in two extemporaneous syrup preparations was studied. Film-coated methyldopa tablets were triturated and incorporated into (1) unpreserved Syrup USP and (2) an equal mixture of simple syrup containing 0.5% citric acid and 0.