ABSTRACT
In birds, the use of corticosterone (Cort) implants is a frequent tool aimed at simulating systemic elevations of this hormone and studying effects on biological traits (e.g. physiology, morphology, behavior). This manipulation may alter adrenocortical function, potentially changing both baseline (CortBAS) and stress-induced (CortSTRESS) plasma Cort levels. However, implant effects on the latter trait are rarely measured, disregarding downstream consequences of potentially altered stress responses. Here, we analyzed the effects of Cort implants on both CortBAS and CortSTRESS in nestling and adult European white storks, Ciconia ciconia In addition, we performed a review of 50 studies using Cort implants in birds during the last two decades to contextualize stork results, assess researchers' patterns of use and infer current study biases. High and low doses of Cort implants resulted in a decrease of both CortBAS (31-71% below controls) and CortSTRESS (63-79% below controls) in storks. Our literature review revealed that CortBAS generally increases (72% of experiments) whereas CortSTRESS decreases (78% of experiments) following implant treatment in birds. Our results challenge and expand the prevailing assumption that Cort implants increase circulating CortBAS levels because: (i) CortBAS levels show a quadratic association with implant dose across bird species, and decreased levels may occur at both high and low implant doses, and (ii) Cort implants also decrease CortSTRESS levels, thus producing stress-hyporesponsive phenotypes. It is time to work towards a better understanding of the effects of Cort implants on adrenocortical function, before addressing downstream links to variation in other biological traits.
Subject(s)
Birds/physiology , Corticosterone/pharmacology , Drug Implants/pharmacology , Stress, Physiological/drug effects , Animals , Dose-Response Relationship, Drug , Drug Implants/classification , Male , Random AllocationABSTRACT
INTRODUCTION: Although hormonal contraceptives may help acne or worsen it, there is limited evidence on the effects of many commonly prescribed agents. The present study evaluates patient-reported effect on acne from 2147 patients who were utilizing a hormonal contraceptive at the time of their initial consultation for acne.
METHODS: At the time of initial consultation for acne, each of 2147 consecutive patients using hormonal contraception provided her assessment of how her contraceptive had affected her acne. The Kruskal-Wallis test and logistic regression analysis were used to compare patient-reported outcomes by contraceptive type.
RESULTS: Depot injections, subdermal implants, and hormonal intrauterine devices worsened acne on average, and were inferior to the vaginal ring and combined oral contraceptives (COCs; P ≤ .001 for all pairwise comparisons), which improved acne on average. Within COC categories, a hierarchy emerged based on the progestin component, where drospirenone (most helpful) > norgestimate and desogestrel > levonorgestrel and norethindrone (P ≤ .035 for all pairwise comparisons). The presence of triphasic progestin dosage in COCs had a positive effect (P = .005), while variation in estrogen dose did not have a significant effect (P = .880).
CONCLUSIONS: Different hormonal contraceptives have significantly varied effects on acne, including among types of COC.
J Drugs Dermatol. 2016;15(6):670-674.
Subject(s)
Acne Vulgaris/diagnosis , Acne Vulgaris/drug therapy , Contraceptive Devices, Female , Contraceptives, Oral, Combined/administration & dosage , Contraceptives, Oral, Combined/classification , Drug Implants/administration & dosage , Acne Vulgaris/chemically induced , Adolescent , Adult , Contraceptive Devices, Female/adverse effects , Contraceptive Devices, Female/classification , Contraceptives, Oral, Combined/adverse effects , Contraceptives, Oral, Hormonal/administration & dosage , Contraceptives, Oral, Hormonal/adverse effects , Contraceptives, Oral, Hormonal/classification , Delayed-Action Preparations , Drug Implants/adverse effects , Drug Implants/classification , Female , Humans , Middle Aged , Retrospective Studies , Young AdultABSTRACT
In this study, a novel approach for compression of matrix pellets into disintegrating tablets has been studied in an attempt to overcome the issues pertaining to rupture of polymer coat during compression of reservoir-type pellets. Extended release matrix pellets were prepared by the extrusion/spheronization technique using commercially available aqueous dispersions of ethyl cellulose, acrylic polymers and sodium alginate at 10%, 20% and 30%w/w levels. Sertraline hydrochloride was used as the model drug and an in vitro release profile of 12 h was targeted. Tablets containing matrix pellets were prepared by the direct compression process. Acceptance Value, a pharmacopeial test, was applied to study the uniformity of drug distribution. Effect of compression force (2-6 kN), extrusion screen aperture size, diluent blend composition and pellet percentage on drug release and acceptance value were studied. As polymer is uniformly distributed within each pellet, the drug release pattern from uncompressed pellets was comparable to compressed tablets. Surface morphological changes due to calcium chloride treatment were observed using Scanning electron microscopy. The pellet segregated from the surface of the tablet was found to be flattened in the direction of applied compression force with minor deformities. In conclusion, matrix pellets can constitute an alternative approach to reservoir-type pellets in obtaining disintegrating tablets for extended delivery of drugs.
Nesse trabalho, estudou-se nova abordagem para a compressão de matrizes de péletes em comprimidos desintegrantes, com o intuito de resolver os problemas relativos à ruptura do polímero de revestimento durante a compressão dos péletes do tipo reservatório. Matrizes de péletes de liberação estendida foram preparadas pela técnica de extrusão/esferonização, utilizando dispersões aquosas comercialmente disponíveis de etil celulose, polímeros acrílicos e alginato de sódio a 10%, 20% e 30% p/p. O cloridrato de sertralina foi utilizado como fármaco modelo e focalizou-se no perfil de liberação in vitro de 12 horas. Os comprimidos contendo matrizes de péletes foram preparados pelo processo de compressão direta. O valor de aceitação, teste farmacopéico, foi aplicado para estudar a uniformidade de distribuição do fármaco. O efeito da força de compressão (2-6 kN), o tamanho da abertura de extrusão, a composição da mistura diluente, a porcentagem de pélete na liberação de fármaco e o valor de aceitação foram estudados. Como o polímero é uniformemente distribuído dentro de cada pélete, o padrão de liberação do fármaco dos péletes não-comprimidos foi comparável àquele dos comprimidos. As mudanças morfológicas da superfície devidas ao tratamento com cloreto de cálcio foram observadas utilizando-se a microscopia eletrônica de varredura. O pélete segregado da superfície do comprimido mostrou-se plano em direção à força de compressão aplicada com menores deformidades. Em conclusão, os péletes matriz podem se constituir em abordagem alternativa para péletes do tipo reservatório na obtenção de comprimidos desintegrantes para fármacos de liberação estendida.