Comparison of Medical Tape Performance Using Skin Response Quantitative Measurements on Healthy Volunteers

BACKGROUND

Medical tapes can lead to skin damage upon removal in susceptible patients with fragile skin and at higher risk of developing tissue injury.

PURPOSE

We compared the effect of medical tapes with silicone-based versus acrylate-based adhesives on the back or volar forearm stratum corneum using analytical techniques to assess skin condition and potential damage post product removal on 88 healthy volunteers.

METHODS

Two studies were conducted in separate facilities (Study 1: 3M In-house Clinical Facility, St. Paul, Minnesota; Study 2: DermiCo, LLC, Broomall, Pennsylvania). Four commercially available tapes were the same in both studies, two for each type of adhesive. We evaluated adhesion to the skin, total proteins and corneocytes removed by the tapes, changes in transepidermal water loss (TEWL), and induction of the inflammatory cytokine interleukin-1 alpha (IL-1a).

RESULTS

One of the silicone tapes displayed the strongest adhesion at 24 hours, and one of the acrylate tapes had the lowest adhesion, showing differences in performance within adhesive categories. The adhesion forces did not correlate with the amount of total protein or corneocytes removed. Silicone adhesives removed less total protein and corneocytes than acrylate adhesives. Silicone adhesives did not alter TEWL, whereas acrylate adhesives significantly raised TEWL. There were no differences in interleukin-1alpha induction.

CONCLUSION

The silicone adhesive tapes were less disruptive to the skin barrier than the acrylate adhesive tapes, even in healthy volunteers whose skin is not as fragile as what is observed in typical patients. This type of data could guide clinical product usage decisions.

The effect of cholecystokinin octapeptide on rat striatal 3H spiperone binding

In the rat striatum sulphated CCK8 has no significant effect on equilibrium binding of 3H-spiperone but has a considerable, although transient, effect under non-equilibrium conditions. Under non-equilibrium conditions (during the association phase of ligand binding) and at high ligand concentrations (1 nM), CCK8 displaces specific binding and at low ligand concentrations (0.1 nM) CCK8 enhances specific binding. CCK8 has no effect on 3H-spiperone dissociation kinetics.

In vivo evidence for the selectivity of ICI 154129 for the delta-opioid receptor

The in vivo selectivity of the novel delta opioid-receptor antagonist N,N-bisallyl-Tyr-Gly-Gly-psi-(CH2S)-Phe-Leu-OH (ICI 154129) was examined in several opioid-selective models. Antagonism at the delta receptor was demonstrated in the striatal head-turn model in the rat. Intrapallidal injection of the relatively selective delta-receptor agonist D-Ala2,D-Leu5-enkephalin (0.5 micrograms) slowed the head-turn time and this effect was completely prevented by prior subcutaneous administration of ICI 154129 (30 mg/kg). The role of delta receptors in two classical test situations was studied using the mixed opioid agonist etorphine and the antagonists naloxone and ICI 154129. The drug ICI 154129 (30 mg/kg, s.c.) failed to prevent the antinociceptive effects and stimulation of locomotor activity produced by etorphine, whereas the relatively selective mu-opioid receptor antagonist, naloxone was effective in both test situations. The possible involvement of delta receptors in morphine-induced dependence was studied by monitoring the abstinence behaviour precipitated in rats given pellets of morphine by either ICI 154129 or naloxone. Naloxone (0.5 mg/kg, i.p.) precipitated a characteristic withdrawal syndrome in conscious rats and, at a much smaller dose (0.02 mg/kg, i.p.), induced shaking behaviour in pentobarbitone-anaesthetised rats. No withdrawal signs were observed in either model after injection of ICI 154129 (30 mg/kg, s.c.), suggesting that the delta receptors are not involved in dependence on morphine.

GABA receptor multiplicity. Visualization of different receptor types in the mammalian CNS

Receptors for GABA in the mammalian brain are not homogeneous. A clear separation exists between receptors which recognize the antagonist bicuculline and a population which does not. These two classes have been designated GABAA and GABAB sites respectively. Within the GABAA category there may also be many subtypes which exhibit subtle pharmacological differences. Numerous centrally-active agents influence GABAA site function generally via an allosteric interaction. By comparison very few substances currently available interact with GABAB sites. The GABAA and GABAB sites show many contrasting characteristics not least of which is their distribution pattern within the rat brain. Autoradiographic analysis has indicated that although both receptors may be present within many regions, in some areas only one type is present. For example, GABAA sites only are present in the lamina molecularis of the olfactory bulb and granule cell layer of the cerebellum whereas GABAB sites are present in the interpeduncular nucleus without any evidence of GABAA sites. In the spinal cord GABAB sites are unevenly distributed with high densities in laminae I-IV. GABAA sites are more uniformly distributed throughout the dorsal and ventral horns. In conclusion, there is now good evidence for multiple GABA receptors and the way is open to determine the functional significance of the GABAB receptor in relation to the now classical GABAA site.

Are baclofen-sensitive GABAB receptors present on primary afferent terminals of the spinal cord?

The site of action of the antispastic drug baclofen has long been considered to reside in the spinal cord although supraspinal effects have also been reported. This beta-chlorophenyl derivative of the neurotransmitter gamma-aminobutyric acid (GABA) depresses both monosynaptic and polysynaptic transmission in the cord possibly through a decrease in transmitter release rather than by any antagonism at postsynaptic receptors. Recently, baclofen has been shown to be a selective ligand for a bicuculline-insensitive GABA receptor (GABAB) site that occurs widely in the mammalian central nervous system including the spinal cord. The apparent importance of the cord in the therapeutic effects of this drug prompted us to ask whether they involve GABAB site activation. As an initial step we have located these receptors by autoradiography, comparing them with classical GABAA sites. We report here that GABAB sites, unlike GABAA sites, are present in high concentrations in laminae I, II, III and IV of the dorsal horn and that after the neonatal administration of capsaicin this binding is reduced by 40-50%.

Actions of substance P, MIF, TRH and related peptides in the substantia nigra, caudate nucleus and nucleus accumbens

Neurones in the substantia nigra were found to be sensitive to iontophoretically applied substance P, substance P 1-9 methyl ester and substance P 1-9 amide. Substance P 1-2, 4-9 and 5-9 methyl esters, thyrotropin releasing hormone (TRH), Pyroglutamyl-histidyl-2 methyl prolineamide (methyl TRH), Pyroglutamyl-histidyl-2 methyl prolineamide (methyl TRH), histidyl-proline-diketopiperazine (His-Pro) and MSH releasing inhibiting factor (MIF) were without effect on neurones in this area. Thyrotropin releasing hormone (TRH), methyl TRH, His-Pro and MIF were inactive on neurones in the caudate nucleus and nucleus accumbens. Bilateral injections of substance P and substance P 1-9 methyl ester into the ventral tegmental area (VTA) of conscious rats produced locomotor activity, while similar injections of substance P 4-9 and 5-9 methyl esters did not. The locomotor activity produced by amphetamine was prolonged by TRH, while MIF was devoid of such activity. The data suggest that substance P and substance P 1-9 have similar effects in the substantia nigra, although the mechanism of action is unclear. Thyrotropin releasing hormone and MIF probably do not have acute actions in the brain areas tested.

Bicuculline-insensitive GABA receptors on peripheral autonomic nerve terminals

The action of gamma-aminobutyric acid (GABA) and related compounds on rat isolated atria and mouse and guinea pig isolated vas deferens has been studied. GABA depressed the evoked but not basal release of [3H]noradrenaline from atria (IC50 4 micro M) and reduced the twitch responses of the vas deferens (IC50 3 micro M) in a dose-dependent manner. These depressant effects were not prevented by recognized GABA antagonists such as bicuculline and picrotoxin. Numerous GABA analogues, in particular 3-aminopropanesulphonic acid, failed to mimic the action of GABA. However, beta-p-chlorophenyl GABA (baclofen) was stereospecifically active. Other related beta-substituted derivatives were also active but to a lesser degree than GABA. Pretreatment of the vas deferens with the neuronal GABA uptake inhibitors 2,4-diaminobutyric acid or cis-3-aminocyclohexanecarboxylic acid potentiated the action of GABA. These data suggest the presence of a bicuculline-insensitive GABA receptor on autonomic nerve terminals. Preliminary observations indicate a lack of chloride ion dependence in the action of GABA at this site.

Effect of pretreatment with bronchodilator drugs on in vitro responsiveness of guinea pig lung adenylate cyclase

Pretreatment of guinea pigs with 5 microgram/kg isoprenaline or 10 microgram/kg salbutamol s.c. thrice daily for 7 days reduced the responsiveness of lung slice and tracheal ring adenylate cyclase to isoprenaline, but not to prostaglandin E1. Pretreatment of guinea pigs with isoprenaline also reduced the sensitivity of tracheal smooth muscle strip adenylate cyclase to isoprenaline. Cross-tolerance developed to noradrenaline in lung slices obtained from guinea pigs pretreated with isoprenaline. Propranolol blocked the response of lung slice adenylate cyclase of control and isoprenaline-pretreated animals to approximately the same degree. The presence of phentolamine in the incubation medium did not affect the reduced sensitivity to isoprenaline. Possible mechanisms of development of tolerance to sympathomimetic bronchodilator drugs are discussed.

In vitro profile of some opioid pentapeptide analogues

The opiate agonist potency of thirteen synthetic enkephalin pentapeptides has been examined on the electrically stimulated guinea pig ileum and mouse vas deferens preparations in comparison with methionine and leucine enkephalins, beta-endorphin and normorphine. Their antagonism by naloxone (Ke) was also assessed on each preparation. Our findings are compatible with, and are discussed in the context of, the hypothesis that these preparations possess at least two populations of receptors.

Urinary monoamine metabolite excretion in disorders of movement. Effects of amantadine and levodopa

We have studied the urinary excretion of 1,4-methylhistamine (1,4-MeHm), 5-hydroxyindole-3-acetic acid (5-HIAA) and homovanillic acid (HVA) in patients with Parkinson's disease, choreiform movements and essential tremor. The effect of amantadine on urinary excretion has been measured in each group of patients as well as the effect of levodopa in patients with Parkinson's disease. In patients with Parkinson's disease, excretion of 1,4-MeHm and HVA was significantly lower than in controls. Patients with choreiform movements had a reduced excretion of HVA but trends toward low levels of 1,4-MeHm and, in patients with Huntington's chorea, elevated excretion of 5-HIAA, were not significant. In patients with essential tremor, urinary excretion of the amine metabolities studied did nof differ significantly from controls. Administration of amantadine to patients with Parkinson's disease was not followed by increased excretion of monoamine metabolites except in those patients who were already receiving anticholinergic drugs. This increase is not significant and there was no effect in other groups of patients. These findings lend no support to the view that amantadine has a general amine-releasing action although there is limited evidence for such an effect in Parkinson's disease. In addition to the expected increase in HVA excretion, administration of levodopa to Parkinsonian patients was followed by significantly reduced excretion of 1,4-MeHm and 5-HIAA. However, if amantadine and levodopa were given together, excretion of 5-HIAA was still reduced, but that of 1,4-MeHm was normal. Levodopa may thus modify the turnover of histamine, which appears to be reduced in Parkinson's disease, and this effect may be modified by amantadine.

Sodium valproate in chorea

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Determination of halothane-induced sleeping time in the rat: effect of prior administration of centrally active drugs

A method is described for the determination of halothane-induced sleeping time in the rat. 2 The sleeping time exhibited a diurnal variation which was due, at least in part, to a change in the sensitivity of the central nervous system (CNS) to the anaesthetic. 3 Tolerance to halothane did not develop in rats repeatedly exposed to the anaesthetic over a period of over 48 hours. 4 Repeated sleeping time determinations have been used to follow changes in the sensitivity of the CNS to the anaesthetic occurring with time. 5 A tolerance to halothane was induced by pretreatment of rats with doses of amylobarbitone, pentobarbitone or meprobamate sufficient to keep animals anaesthetized for approximately 12 hours. This tolerance was followed by a period of halothane-hypersensitivity. 6 Halothane-tolerant animals awakened with higher brain halothane concentrations and were also tolerant to intracerebroventricularly administered pentobarbitone. 7 Halothane-hypertensive rats awakened with lower brain halothane concentrations and were also hypersensitivity to intracerebroventricularly administered pentobarbitone. 8 The possibility that the induction of cross-tolerance to halothane may be indicative of a drug's potential to produce dependence is discussed.

Acute tolerance to barbiturate in the rat

3 experimental approaches to the quantitation of acute barbiturate tolerance have been compared in the rat. There was no difference between the brain hexobarbitone or barbitone concentration found at the time of loss of righting reflex compared with the concentration found on return of the righting reflex following the period of anaesthesia produced by a single i.p. injection of the drug. However, tolerance was induced by a 7 hr infusion of pentobarbitone which kept rats anaesthetized for approximately 8 hr. Such rats awakened with a significantly higher brain pentobarbitone concentration compared with rats awakening after a single i.p. injection. Repeated i.p. injections of pentobarbitone, sufficient to keep animals anaesthetized for 12 hr, also induced a tolerance to pentobarbitone, as indicated by a reduced sleeping time and higher brain barbiturate concentration on awakening following intracerebroventricularly administered pentobarbitone injected 12 hr after the last i.p. injection. The possible relationship between acute cellular tolerance and physical dependence is discussed.

The pharmacology of Avena sativa

The pharmacology of Avena sativa has been investigated in laboratory animals following a report that tincture of Avena sativa reduced the craying for cigarettes in man. The tincture, evaporated to dryness, craving for cigarettes in man. The tincture, evaporated to dryness, re-constituted in an equal volume of water and administered by stomach tube or intraperitoneal injection, antagonized the antinociceptive effect of morphine in two separate test (hot-plate and tail flick). Compared with animals made depedent on morphine alone, mice pretreated with repeated injections of morphine plus extract passed a smaller number of stools and tended to jump less after administration of nalorphine. The pressor response to intravenously administered nicotine in urethane-anaesthetized rats was also antagonized by prior administration of Avena sativa. However, the aqueous extract prepared from the tincture did not affect the seizure threshold to bemegride or nicotine or the sleeping time induced by barbitone sodium.

A study of the factors affecting the sleeping time following intracerebroventricular administration of pentobarbitone sodium: effect of prior administration of centrally active drugs

1 Injection of pentobarbitone sodium into a lateral cerebral ventricle of rats produced a loss of righting reflex. The duration of anaesthesia was dose-dependent.2 The optimum dose of pentobarbitone to allow study of the factors affecting the sleeping time was considered to be 650 mug injected in 25 mul water.3 In a study of the effect of age and sex on the sleeping time, the youngest rats used (88 g body weight) were found to be the most sensitive to barbiturate. Female rats were more sensitive than male animals.4 The duration of anaesthesia was not affected by induction or inhibition of hepatic drug-metabolizing enzyme activity.5 Prior administration (acute) of central nervous system depressant drugs shortened the latent period and prolonged the duration of sleep. Prior administration of stimulant drugs antagonized the effect of pentobarbitone.6 Animals withdrawn following chronic administration of a number of drugs, barbitone, barbitone/bemegride mixture, Mandrax (methaqualone: diphenhydramine; 10: 1), chlordiazepoxide, nitrazepam, chlorpromazine or ethanol, exhibited a significant tolerance to intracerebroventricularly administered pentobarbitone.7 Withdrawal of amphetamine, morphine, methyprylon or diazepam did not result in tolerance to intracerebroventricularly administered pentobarbitone.8 Chronic administration of all drugs except amphetamine and morphine induced a tolerance to intraperitoneally administered hexobarbitone (100 mg/kg).9 The usefulness of sleeping time determination following intracerebroventricular administration of pentobarbitone as an assessment of central nervous system excitability is discussed. It is concluded that this method gives a valid indication of the sensitivity of the central nervous system to barbiturate and of the level of excitability in general. The method is particularly applicable in situations where the activity of hepatic drug-metabolizing enzyme activity may be altered.

Effect of chronic L-DOPA administration of catecholamine metabolism in the rat

1. L-DOPA was administered to rats by twice daily intraperitoneal injection for a period of eleven days. The daily dose was gradually increased from 250 mg/kg to 1 g/kg. The animals were killed 12 h after the last injection and tissue catechol-O-methyl transferase, DOPA-decarboxylase and monoamine oxidase activity determined.2. Catechol-O-methyl transferase activity was reduced in the liver (46%) and red blood cells (38%) but was approximately doubled in the heart.3. Liver DOPA-decarboxylase activity was reduced by approximately 25%.4. L-DOPA administration did not significantly affect the activity of any of the enzymes studied in brain tissue.