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PubMedDate not supplied

Liquid chromatographic determination of clobetasone-17-butyrate in ointments.

A liquid chromatographic (LC) method has been developed for determination of clobetasone-17-butyrate in ointment using clobetasone propionate as an internal standard. Separation was carried out on a C18 reverse-phase column using water-methanol as a mobile phase. Methylparaben and propylparaben (both sodium salt) used as preservatives did not interfere with separation. Compounds are detected photometrically at 235 nm. Mean assay results for 0.05% commercial ointments were 100.36% (n = 5). Mean recovery of clobetasone-17-butyrate added to commercial ointment was 99.89%.

Administration, Topical↗
PubMed1975

Studies of properties and potential applications of some soluble salts of cellulose acetate phthalate. Part 1: rheological behavior and aging effect.

Rheological behaviour for solutions of the sodium, ammonium, and triethanolamie salts of cellulose acetate phthalate was studied. The comparative resistance to microbial growth and to changes in pH values exhibited by these solutions on storage was also investigated. The results indicated that the viscosities of these solutions were temperature and concentration dependent and that increasing the rate of shear produced only a slight increase of viscosity. Solutions of ammonium and the triethanolamine salts did not support any apparent microbial growth during storage at room temperature of three weeks, but the sodium salt appeared to suffer from microbial contamination. However, the use of a mixture of 0.15% methylparaben and 0.05% propylparaben prevented such contamination. The pH values of all the slat solutions studied appeared to decrease on storage.

Acetates↗
PubMed1987

Adrenocortical suppression by topically applied corticosteroids in healthy dogs.

Three corticosteroid products (triamcinolone acetonide, fluocinonide, betamethasone valerate) and a control product composed of water, petrolatum, mineral oil, cetyl alcohol, steryl alcohol, sodium lauryl sulfate, cholesterol, and methylparaben each were applied topically to healthy dogs (5 dogs/product) once daily for 5 consecutive days. Plasma concentrations of immunoreactive adrenocorticotropic hormone (iACTH) and cortisol were determined before 1 microgram of ACTH/kg of body weight was given intravenously (pre-ACTH values) and cortisol was again measured 60 minutes after ACTH was given (post-ACTH values). Cortisol and iACTH concentrations were determined in each dog before, during, and after administration of the corticosteroid products. All 3 corticosteroids caused prompt and sustained pituitary-adrenocortical suppression. Compared with control applications, the application of corticosteroids resulted in significant reduction of plasma cortisol and iACTH concentrations by day 2 of treatment, and the lower concentrations continued to day 5. One week after the last application of the corticosteroids, plasma iACTH concentrations in the corticosteroid-treated dogs had returned to the range of values for the control dogs; however, pre- and post-ACTH cortisol concentrations remained suppressed in all corticosteroid-treated dogs. Two weeks after the last treatment, the pre-ACTH plasma cortisol concentrations of corticosteroid-treated dogs returned to those of the control dogs, but the post-ACTH plasma cortisol concentrations remained suppressed. By 3 weeks after the last treatment, post-ACTH plasma cortisol concentrations of dogs treated with triamcinolone acetonide had returned to the range of values for the control dogs, but remained suppressed in the other 2 groups of dogs. All indices of pituitary-adrenocortical activity were within the control range by 4 weeks after the last treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMed1988

Parabens as antimicrobial preservatives in creams.

Antimicrobial effectiveness of methylparaben and a mixture of methyl- and propylparabens in an oil-in-water cream was studied. How the number of microbes and inclusion of nutrients into the cream affect the effectiveness of these compounds were also investigated, as well as the survival of test microbes in the cream without preservatives. Survival of microbes and antimicrobial effectiveness of parabens against the microbes in the cream were dependent on the species and number of microbes present and also on the amount of nutrients available for the microbes. In spite of the large amount of water, the cream studied did not readily support microbial growth unless the number of microbes was large or nutrients were added. Parabens were not effective antimicrobial agents against the yeast studied. The bacterial species showed different sensitivities to parabens. A mixture of methyl- and propylparabens was more effective than the methylester alone.

Bacteria↗
PubMed1986

Subconjunctival injections. Preservative-related changes in the corneal endothelium.

The morphologic effects on rabbit corneal endothelium of several common ophthalmic vehicle constituents were examined following subconjunctival administration. Profound dose-dependent changes consisting of intercellular vacuolization and thickening of the endothelial layer were noted within 1 day following administration of solutions that contained sodium bisulfite or methylparaben and propylparaben. These changes persisted for at least 5 days except in those eyes treated with the lowest concentration of sodium bisulfite. In contrast, administration of sodium citrate and creatinine or unpreserved normal saline resulted in only minimal effects. These changes are of concern because these agents are present in many preparations used to treat a wide variety of eye diseases.

Animals↗
PubMed1977

Paraben allergy.

A hydrocortisone preparation containing methylparaben and propylparaben provoked bronchospasm and pruritus when given intravenously to an asthmatic patient, whereas another hydrocortisone preparation without paraben preservative did not. Direct and passive transfer (Prausnitz-Küstner) skin tests for immediate hypersensitivity to parabens were positive. Parabens, frequently employed as bacteriostatic agents, are capable of producing immunologically mediated, immmediate systemic hypersensitivity reactions.

Asthma↗
PubMed1983

Effects of the constituents of a corticosteroid enema preparation on colonic blood flow and oxygen uptake in the dog.

A number of currently available therapeutic agents for the management of idiopathic inflammatory bowel disease were studied with respect to their influence on blood flow and oxygen extraction in the dog colon. Some commercially available corticosteroid enemas including Cortenema and its vehicle and sulfasalazine and its split products were delivered intraluminally while arterial pressure, blood flow and oxygen extraction in autoperfused segments of the colon were continuously monitored. Of the agents studied, only Cortenema and its vehicle exerted any appreciable effect on colonic blood flow, producing a sustained 50% increase; this increase in blood flow was confined to the mucosa-submucosal layer. Of the constituents of Cortenema, methylparaben was responsible for 72% of the hyperemia whereas the remainder was due to carboxypolymethylene. The corticosteroid itself had no effect. Oxygen uptake by the colon was reduced by approximately 10% with Cortenema, this reduction being due entirely to polysorbate 80. In vitro analysis of the oxygen uptake effect indicates that the enema exerts a direct metabolic action.

Acrylic Resins↗
PubMed1982

Stability of haloperidol in 5% dextrose injection.

The stability of haloperidol in 5% dextrose injection using a high-pressure liquid chromatographic (HPLC) method is reported. A solution of haloperidol 10 mg/dl in 5% dextrose injection was prepared using commercially available haloperidol injection. The solution was stored at 24 degrees C, half in an amber glass bottle and half in a plastic bag. These were assayed on days 0, 1, 7, 14, and 38. Solutions prepared from commercial dosage forms of haloperidol (injection, oral liquid concentrate, and tablets) were assayed to verify the accuracy of the HPLC assay to quantify haloperidol. There was no loss of haloperidol potency in 38 days when stored 24 degrees C in either the amber glass bottle or plastic bag. There was a substantial loss of methylparaben and propylparaben (present in commercial haloperidol injection) in the solution stored in the plastic bag. Oxidation products of haloperidol did not interfere with the assay, and the HPLC assay accurately measured haloperidol in solutions prepared from commercial dosage forms. The results show that haloperidol 10 mg/dl in 5% dextrose injection was stable for at least 38 days. While the loss of parabens is not of practical importance, the HPLC method developed provided this information while the previously used USP-NF procedure did not. The assay can be used to quantify haloperidol in commercial dosage forms.

Chemistry, Pharmaceutical↗
PubMed1993

The mystery ingredients: sweeteners, flavorings, dyes, and preservatives in analgesic/antipyretic, antihistamine/decongestant, cough and cold, antidiarrheal, and liquid theophylline preparations.

OBJECTIVE: Pharmaceutical preparations may contain a variety of excipients ("inert ingredients"). These excipients are generally inactive; however, rare adverse effects caused by excipients have been reported. Information about the excipients in a particular preparation is not readily available. METHODS: The information about sweeteners, flavorings, dyes, and preservatives for the chewable and liquid preparations of over-the-counter and prescription products of antidiarrhea, cough and cold, antihistamine/decongestant, analgesic/antipyretic, and liquid theophylline medications was collected. RESULTS: Information about excipients in 102 chewable and liquid preparations was compiled. An average preparation contained two sweeteners. Saccharin and sucrose were the most common sweeteners found--each was present in 52 preparations--followed by sorbitol, glucose, fructose, and others. For 36 of the 102 preparations, type of flavoring was not specified. In the remaining preparations, cherry was the most common flavoring, followed by vanilla and lemon. Twenty-one different dyes and coloring agents were used. Red dye No. 40 was the most common (42/102), followed by yellow No. 6 (27/102). Of the eight preservatives used, sodium benzoate and methylparabens were present in 42 and 27 of the preparations, respectively. Tables detailing these excipients and adverse effects reported are presented. CONCLUSIONS: The tables should be helpful to physicians in selecting preparations containing different excipients when an adverse reaction occurs. The mandatory labeling of excipients in all pharmaceutical preparations is the only way that physicians and patients can be fully informed.

Analgesics↗
PubMedDate not supplied

Liquid chromatographic determination of atropine in nerve gas antidotes and other dosage forms.

A simple and specific liquid chromatographic method was developed for the determination of atropine in nerve gas antidotes and several other dosage forms. The method is also used simultaneously to quantitate phenol, an antimicrobial agent present in nerve gas antidotes, and to monitor the level of tropic acid, a principal degradation product of atropine. The system uses a Spherisorb CN column and a mobile phase of acetonitrile-0.05M sodium phosphate monobasic (10 + 90), pH 4.0. The detection wavelength is 220 nm. The method was validated by testing for accuracy, linearity, reproducibility and precision. In addition, the proposed method was applied to 8 commercial preparations of atropine, including injectables, ophthalmic solutions, and ointments, and was found to be satisfactory and free from interferences from preservatives, such as benzyl alcohol, methylparaben, benzalkonium chloride and chlorobutanol, that are present in these formulations.

Antidotes↗
PubMed1995

[Preservation and stability of corn tortillas at room temperature].

Three treatments with chemical preservative (sodium propionate, potassium sorbate-methylparaben and hydrogen peroxidemethyl paraben) were tested to delay microbial spoilage and extend shelf-life of corn tortillas at room temperature (25 degrees C). The treatment with the best results was selected for further studies using two types of packaging: Paper and high density polyethylene. Quality of corn tortillas during storage was assessed by measuring water content, microbial analysis (Total Plate Count, molds and yeast) and throguh sensory evaluation. Results were analyzed by covariance analysis and slope contrast between packaging materials at p<0.05. Spoilage of tortilla without preservative occurred within 24 hours due to a large number of gram negative bacteria, molds and yeasts, which were responsible for offensive odors. Only the combination of hydrogen peroxide-methyl paraben had a significant effect on retarding bacterial yeast spoilage. In addition, hydrogen peroxide residues could not [correction of no] be chemically detected after 2 days of storage. Results from this study show that tortilla can be kept for up to six days at room temperature with acceptable sensory properties with proper preservative treatment and packaging.

Analysis of Variance↗
PubMed1976

Stability of gentamicin sulfate injection following unit dose repackaging.

The potency of gentamicin sulfate following repackaging in disposable syringes were determined by a modification of the agar diffusion bioassay, using a highly gentamicin-resistant strain of Psuedomonas aeruginosa to assay milligram quantities of active drug. Three factors were studied at 30, 60 and 90 days: (1) syringe character (glass vs plastic); (2) temperature (25 C vs 4 C); and (3) volume of aspirated sample. Glass syringes were superior at all time intervals. Storage in plastic for even 30 days resulted in unacceptable loss of potency (greater than 15%) and formation of a brown precipitate. Mass spectrophotometry indicated that this precipitate consisted mainly of esters of phthalic acid (plasticizer) and methylparaben (gentamicin preservative). Temperature had no effect on retained potency. A positive correlation between the percent potency lost and volume of gentamicin aspirated was demonstrated in both glass and plastic.

Drug Packaging↗