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PubMed1986

Onset time of action and duration up to 3 hours of nitroglycerin in buccal, sublingual and transdermal form.

Nitroglycerin in sublingual, buccal and transdermal administration forms were compared in 10 patients with stable exercise-induced angina pectoris with respect to onset time of action and efficacy one and three hours after administration, using bicycle exercise to provoke chest pain. Anti-anginal and anti-ischaemic effects (as judged by influence on electrocardiographic ST depression) began within 2 minutes of application of the buccal and sublingual forms, whereas the transdermal patch did not show such effects within nine minutes of application. One and three hours after application, the sublingual form had no effect whereas both the transdermal and buccal forms significantly increased exercise capacity and improved electrocardiographic ST segment changes. The 2.5 mg buccal tablet was more effective than the 10 mg transdermal patch. An additional observation was that a light snack at 2 hours significantly decreased exercise capacity at 3 hours whether or not active treatment had been instituted.

Administration, Cutaneous↗
PubMed2000

Comparison of pharmacokinetics of fentanyl after intravenous and transdermal administration in cats.

OBJECTIVE: To compare pharmacokinetic and pharmacodynamic characteristics of fentanyl citrate after IV or transdermal administration in cats. ANIMALS: 6 healthy adult cats with a mean weight of 3.78 kg. PROCEDURE: Each cat was given fentanyl IV (25 mg/cat; mean +/- SD dosage, 7.19 +/- 1.17 mg/kg of body weight) and via a transdermal patch (25 microg of fentanyl/h). Plasma concentrations of fentanyl were measured by use of radioimmunoassay. Pharmacokinetic analyses of plasma drug concentrations were conducted, using an automated curve-stripping process followed by nonlinear, least-squares regression. Transdermal delivery of drug was calculated by use of IV pharmacokinetic data. RESULTS: Plasma concentrations of fentanyl given IV decreased rapidly (mean elimination half-life, 2.35 +/- 0.57 hours). Mean +/- SEM calculated rate of transdermal delivery of fentanyl was 8.48 +/- 1.7 mg/h (< 36% of the theoretical 25 mg/h). Median steady-state concentration of fentanyl 12 to 100 hours after application of the transdermal patch was 1.58 ng/ml. Plasma concentrations of fentanyl < 1.0 ng/ml were detected in 4 of 6 cats 12 hours after patch application, 5 of 6 cats 18 and 24 hours after application, and 6 of 6 cats 36 hours after application. CONCLUSIONS AND CLINICAL RELEVANCE: In cats, transdermal administration provides sustained plasma concentrations of fentanyl citrate throughout a 5-day period. Variation of plasma drug concentrations with transdermal absorption for each cat was pronounced. Transdermal administration of fentanyl has potential for use in cats for long-term control of pain after surgery or chronic pain associated with cancer.

Administration, Topical↗
PubMed1999

Insulin sensitivity during postmenopausal hormone replacement with transdermal estradiol and intrauterine levonorgestrel.

BACKGROUND: The study was devised to measure the effect of intrauterinely delivered levonorgestrel and transdermal estradiol on insulin sensitivity in postmenopausal women and compare this effect with that induced by transdermal estradiol alone. METHODS: An open, prospective, comparative study of healthy postmenopausal women without earlier use of hormone replacement therapy. The estrogen therapy group consisted of eight hysterectomized women, who used a transdermal patch delivering a daily dose of 50 microg of estradiol continuously for 6 months. The estrogen-progestin therapy group consisted of 13 women with an intact uterus, who received a simultaneous combination of a transdermal patch and a levonorgestrel (20 microg/day) intrauterine system for the same length of time. Fasting plasma concentrations of glucose, insulin and C-peptide and an insulin tolerance test were used to measure glucose metabolism and insulin sensitivity. RESULTS: Neither therapy changed the fasting plasma levels of glucose, insulin or C-peptide. Transdermal estrogen improved insulin sensitivity by 22%, as measured by an insulin tolerance test, while a small increase of 3.6% was observed using the combination therapy. CONCLUSIONS: Transdermal estradiol improves insulin sensitivity in healthy postmenopausal women. Combining intrauterine levonorgestrel to transdermal estradiol reverses this effect. This combination does not, however, seem to induce insulin resistance.

Administration, Cutaneous↗
PubMedDate not supplied

An acute double-blind placebo-controlled study of transdermal glyceryl trinitrate with 12 months' follow-up in patients with stable angina pectoris.

In an acute double-blind placebo-controlled randomized crossover study, 1 day of treatment with a glyceryl trinitrate transdermal patch releasing 10 mg glyceryl trinitrate daily was compared with placebo in 40 men with stable angina pectoris. Subsequently, the patients participated in an uncontrolled efficacy and tolerability study during which the transdermal patch was applied to the front of the chest for 22-23 hours daily for 12 months. In the acute study, one patch of glyceryl trinitrate or matching placebo was applied at 8.00 a.m. for 24 h; 48 h later the other treatment was applied. Bicycle ergometry was performed 24 and 16 h before the beginning of the treatment, and 8 and 24 h after each dose. Ergometry was repeated after 1, 3, 6 and 12 months' treatment with one patch daily of glyceryl trinitrate during the long-term open follow-up study. In the acute study, a significant reduction of ST-segment depression was observed with treatment compared with placebo. This reduction persisted throughout the 12 months of the open study. During this period also, the mean number of anginal attacks was reduced from 5.3 to 3.6 during week 1 of treatment, and this reduction was maintained throughout the 12 months of the study. No patient needed to be withdrawn because of systemic side-effects or local intolerance to the patch.

Administration, Cutaneous↗
PubMed1989

Effectiveness of interval nitrate therapy in angina pectoris.

Because of rapid tolerance development, the use of multiple daily doses of oral nitrates or continuous application of transdermal nitrate systems can no longer be considered justified. Only with an interval treatment, which prevents nitrate accumulation in the plasma such that, from low baseline values, renewed administration of the drug results in a marked increase in plasma concentration, is it possible to utilize the antianginal and antiischaemic effects of nitrates for meaningful long-term treatment. For isosorbide dinitrate and isosorbide 5-mononitrate, as well as for transdermal nitroglycerin systems, interval treatment dosing regimens with maintained effectiveness documented in controlled studies have been delineated. To some degree, the principle of interval treatment can be achieved with continuously applied transdermal patches designed for discontinuous release of their content, which yield maintained though somewhat attenuated effects. Recent studies have shown that the tolerance to nitroglycerin, which develops within the first 12h of contact with currently available transdermal patches, can be prevented by gradually increasing the plasma concentration during this period of time. Evidence for clinically relevant rebound phenomena during interval treatment has not been observed.

Administration, Cutaneous↗
PubMed2000

Transdermal ketamine as an adjuvant for postoperative analgesia after abdominal gynecological surgery using lidocaine epidural blockade.

UNLABELLED: We examined the postoperative analgesia of a controlled delivery ketamine transdermal patch after minor abdominal gynecological surgery using lidocaine epidural blockade. Fifty-two patients were randomized to one of two groups. Epidural anesthesia was performed with 25 mL 2% plain lidocaine. At the end of the surgical procedure, a controlled delivery transdermal patch containing either ketamine (25 mg/24 h) (Ketamine group) or placebo (Placebo group) was applied. Pain and adverse effects were assessed hourly postoperatively for 24 h. IM dipyrone was available at patient request. The two groups were demographically similar. The time to first rescue analgesic was longer in the Ketamine group (230+/-112 min) compared with the Placebo group (94+/-54 min); (P<0.00001). There were more dipyrone dose injections in 24 h in the Placebo group compared with the Ketamine group (P<0.0001). The incidence of adverse effects was similar between groups. We conclude that the transdermal-controlled delivery of ketamine prolonged the duration of analgesia after minor gynecological procedures. IMPLICATIONS: Transdermal delivery of ketamine was an useful adjuvant to postoperative analgesia after epidural lidocaine blockade in the population studied.

Administration, Cutaneous↗
PubMed1998

Moderate alcohol consumption and estrogen levels in postmenopausal women: a review.

This report reviews the literature to evaluate association between moderate alcohol consumption and estrogen levels in healthy postmenopausal women. Of the eight studies available in literature on postmenopausal women who were not on estrogen therapy, two analyzed urine samples and six analyzed blood samples for estrogen levels. Of the two urine sample studies, only one reported positive association (p < 0.05) between alcohol consumption and estrogen (estrone and estradiol) levels that increased by 16 to 20%. Of the six blood sample studies, only two--one in American women and one in European women--reported significant increases (p < 0.05) in estradiol levels in response to alcohol consumption. In the American women study, estradiol levels increased only with wine and not with beer or whiskey. In the European women study, estradiol levels increased in Danish and Portuguese women, but not in Spanish women. Thus, further studies are required to establish correlation between moderate alcohol consumption and estrogen levels in postmenopausal women. Of the two studies on postmenopausal women who were on estrogen replacement therapy, one administered estradiol through transdermal patch (0.15 mg) and one orally (1 mg/day). In both studies, blood estradiol levels were measured after administering a single dose of ethanol orally (0.7-0.75 g/kg of body weight). Estradiol levels were increased by 22 and 300% in the transdermal patch and oral studies, respectively. These results suggest that alcohol consumption may increase blood estradiol levels in postmenopausal women who are on estrogen replacement therapy, and this may increase the risk of breast cancer.

Alcohol Drinking↗
PubMed1991

Clinical efficacy of oral-transdermal clonidine combinations during the perioperative period.

In an attempt to maintain stable levels of an alpha 2-adrenergic agonist throughout the perioperative period, two different oral-transdermal clonidine dosage regimens were administered according to a randomized, double-blind, placebo-controlled study in patients undergoing abdominal surgery. We determined the clinical efficacy of a high- and a low-dose clonidine regimen on sedation, hemodynamic parameters, anesthesia, and analgesia. The low-dose clonidine group of patients (n = 14) received a 7-cm2 clonidine transdermal patch (Catapres-TTS #2), which was supplemented with oral doses of clonidine approximately 3 micrograms.kg-1 on the evening prior to surgery and on the morning of surgery. The high-dose clonidine group (n = 14) received a 10.5-cm2 clonidine transdermal patch (Catapres-TTS #3) with oral clonidine approximately 4.5 micrograms.kg-1 at bedtime and 6.0 micrograms.kg-1 on the morning of surgery. Placebo-treated (control) patients received the same occlusive patch without active ingredient and oral placebo tablets at bedtime and on the morning of surgery. Preanesthetic medication included midazolam 50 micrograms.kg-1 intramuscularly (im). Anesthesia was induced with alfentanil 30 micrograms.kg-1 intravenously (iv), thiopental 3 mg.kg-1 iv, and vecuronium 0.1 mg.kg-1 iv, and was maintained with 70% nitrous oxide in oxygen and a continuous infusion of alfentanil 0.5 microgram.kg-1.min-1. Isoflurane was added when the blood pressure exceeded 110% of the patient's prestudy value. For pain relief postoperatively, the patients received morphine, 1-2-mg iv boluses, via a patient-controlled analgesia pump. The low-dose clonidine patient group had mean plasma clonidine concentrations that varied from 1.47 ng.ml-1 (preoperative) to 1.32 ng.ml-1 (postoperative day 2).(ABSTRACT TRUNCATED AT 250 WORDS)

Adjuvants, Anesthesia↗
PubMed1995

Idiosyncratic ocular symptoms associated with the estradiol transdermal estrogen replacement patch system.

The Estradiol Transdermal Estrogen Replacement Patch System (Estraderm) is designed to provide continuous estrogen replacement therapy through a rate-limiting membrane applied to the skin. The relative advantage of the patch over the more commonly prescribed oral medication, Premarin, is that the drug is absorbed directly into the bloodstream without extended metabolism by the digestive system and the liver. Ocular side effects associated with Estraderm, reported in the literature, include fluctuation in corneal curvature and variations of keratitis sicca. Here, a case is presented in which a 50-year-old Caucasian female, without previous ocular sequelae status after hysterectomy and oophorectomy, experienced what appears to be atypical ocular symptoms associated with the Estraderm. To the best of our knowledge, this information has not been reported in the literature. Clinicians should be aware of the unusual symptoms that could accompany the use of the Estradiol Estrogen Replacement Patch and include them among the differential diagnoses. The condition, its associated symptoms, and summary of the literature are discussed.

Delayed-Action Preparations↗
PubMed2001

Nicotine replacement methods on a psychiatric unit.

UNLABELLED: Patients with psychiatric illness smoke more heavily than others in the community. They have more difficulty quitting and have more withdrawal symptoms than others. OBJECTIVE: The purpose of the present study was to examine the utilization of nicotine replacement methods in a population of psychiatric patients. METHOD: In a naturalistic retrospective review, we examined the records of 55 patients who were hospitalized on a smoke-free psychiatric unit. We abstracted the frequency of utilization of nicotine replacement. The rate of utilization was considered a ratio of the number of days utilized to the number of days prescribed. RESULTS: There were 38 patients (69%) who used the transdermal patch, 26 patients (47%) used the inhaler, 4 patients (7%) used nicotine gum, and 2 patients (4%) used the nasal spray. The rate of utilization of the nicotine inhaler (63%) exceeded that of the transdermal nicotine patch (30%) (t = 4.6, p < .0001). CONCLUSION: The hospitalization of smokers with mental illness in smoke-free psychiatric units often leads to further behavioral deterioration. The patients in the present study demonstrated a definite preference for the nicotine inhaler over the transdermal patch. Possible clinical and pathophysiological implications of this finding are discussed.

Adolescent↗
PubMed2002

Levonorgestrel implants (Norplant II) for male contraception clinical trials: combination with transdermal and injectable testosterone.

Recent studies demonstrate that combinations of androgens and progestagens are highly effective in the suppression of spermatogenesis in normal volunteers. To test whether progestagen and androgen delivery systems designed to produce steady serum levels will be as effective as other androgen plus progestagen combinations, we compared Norplant II and testosterone (T) transdermal patch to T patch alone on the suppression of spermatogenesis in normal men. Thirty-nine healthy male volunteers (age, 20-45 yr) were randomly assigned to one of two groups. Group 1 (n = 19) received two transdermal T patches daily (Testoderm TTS, each patch designed to deliver about 5 mg/d T) alone, and group 2 (n = 20) received combined Norplant II [Jadelle, four capsules delivering approximately 160 microg/d levonorgestrel (LNG)] plus T patch. Neither of these regimens were very effective, with suppression of spermatogenesis to severe oligozoospermia occurring in less than 60% of subjects. We then expanded the study to include two more groups to determine whether T patch or Norplant II was the main factor causing the inadequate suppression of spermatogenesis. Another 29 subjects were randomized to one of two groups. Group 3 (n = 15) received oral LNG (125 microg/d) plus T patch, and group 4 (n = 14) received Norplant II plus T enanthate (TE) injection (100 mg/wk i.m.). After a pretreatment phase of 4 wk, all subjects received treatment for 24 wk, followed by a recovery period of 12-24 wk. Steady-state serum LNG levels (800-1200 pmol/liter) were achieved from wk 3-24 after Norplant II insertion and decreased rapidly after the removal of the implants at wk 24. Trough serum LNG levels after oral LNG administration were at a comparable range (940-1300 pmol/liter). Azoospermia was achieved in 24%, 35%, 33%, and 93%, and severe oligozoospermia (<1 x 10(6)/ml) developed in 24%, 60%, 42%, and 100% of the subjects in groups 1, 2, 3, and 4, respectively, during treatment phase. All subjects in the Norplant II plus TE groups had persistent sperm concentrations less than 3 x 10(6)/ml from wk 12 until the end of treatment. Concomitant with the marked suppression of spermatogenesis in the Norplant II plus TE group, serum FSH and LH levels were most decreased in this group compared with all other groups. In the T patch-only group, serum SHBG was not suppressed, and total serum T was higher than baseline levels. In the other three groups administered progestagens, serum SHBGs were significantly suppressed, and serum total T remained similar to baseline levels. Serum free T levels were not changed in any group. Except for a suppression of serum high-density lipoprotein cholesterol, there was no significant change in weight, hematocrit, clinical chemistry, or prostate-specific antigen levels in any of the treatment groups. Although more efficacious than T patch alone, Norplant II or oral LNG plus T patch was not as effective in suppressing spermatogenesis to severe oligo- or azoospermia as in previous reports using oral LNG plus TE. This relative lesser efficacy occurred despite the achievement of serum LNG levels by Norplant II that were equivalent to those reported after administration of oral LNG. Substituting the transdermal T delivery system with TE injections resulted in very effective suppression of sperm output. The difference in spermatogenesis suppression of these combined regimens is likely due to less T delivered by the transdermal patch compared with the TE weekly injections. We conclude that Norplant II implants plus TE 100 mg/wk were very efficient in suppressing spermatogenesis to a level acceptable for contraceptive efficacy. This study demonstrates that the dose or route of administration of androgens is critical for sperm suppression in combined androgen-progestagen regimens for hormonal male contraception.

Administration, Cutaneous↗
PubMed2004

In vitro/in vivo correlation studies for transdermal delta 8-THC development.

The present study was carried out in order to develop a transdermal therapeutic system (TTS) for Delta(8)-THC. The in vitro permeability studies of Delta(8)-THC in human skin and hairless guinea pig skin with and without a rate-controlling membrane were conducted in flow-through diffusion cells. Delta(8)-THC pharmacokinetic parameters were determined after topical application of transdermal patches and intravenous administration in guinea pigs. The in vitro results indicated that there was no significant difference in the mean flux or in the permeability coefficient of Delta(8)-THC in human skin versus hairless guinea pig skin. The flux of Delta(8)-THC through the human skin/membrane composite was not significantly lower than that through the hairless guinea pig skin/membrane composite; and the skin controlled the Delta(8)-THC delivery rate. Intravenous doses of Delta(8)-THC followed a two-compartment model with a significant distribution phase. On application of the TTS patch, the plasma concentration of Delta(8)-THC reached a mean steady-state level of 4.4 ng/mL within 1.4 h and was maintained for at least 48 h. Significant amounts of metabolites were observed in the plasma after topical application. The in vitro-study predicted plasma concentration following application of the transdermal patch was in agreement with the observed guinea pig plasma concentrations of Delta(8)-THC.

Administration, Cutaneous↗
PubMed1994

Meta-analysis on efficacy of nicotine replacement therapies in smoking cessation.

Nicotine-replacement therapy (NRT) by gum, transdermal patch, intranasal spray, or inhalation is expensive but how effective is it? We have done a meta-analysis of controlled trials to see how effects on abstinence rates are influenced by the clinical setting, the level of nicotine dependency, the dosage of NRT, and the intensity of additional advice and support offered. Published or unpublished randomised controlled trials of NRT that have assessed abstinence at least 6 months after the start of NRT were identified and 53 trials (42 gum, 9 patch, 1 intranasal spray, 1 inhaler), with data from 17,703 subjects, were included in the analyses. Use of NRT increased the odds ratio (OR) of abstinence to 1.71 (95% confidence interval 1.56-1.87) compared with those allocated to the control interventions. The ORs for the different forms of NRT were 1.61 for gum, 2.07 for transdermal patch, 2.92 for nasal spray, and 3.05 for inhaled nicotine. These odds were non-significantly higher in subjects with higher levels of nicotine dependence but they were largely independent of the intensity of additional support provided or the setting in which NRT was offered. We conclude that the currently available forms of NRT are effective therapies to aid smoking cessation.

Administration, Cutaneous↗
PubMed1999

Pharmacokinetics of fentanyl after intravenous and transdermal administration in goats.

OBJECTIVE: To evaluate disposition of fentanyl in goats after IV and transdermal administration. ANIMALS: 8 healthy 2-year-old goats weighing 31.8 to 53.6 kg (mean+/-SD, 40.4+/-7.5 kg). PROCEDURE: Each goat was given 2 treatments consisting of fentanyl administered IV (2.5 microg/kg of body weight) and via a transdermal patch (50 microg/h). There was a 2-month interval between treatments. Blood samples were collected at specified times and analyzed in duplicate to determine plasma fentanyl concentrations. Pharmacokinetic values were calculated, using a computerized modeling program. RESULTS: Administration of fentanyl was tolerated by all goats. Intravenous administration of fentanyl resulted in a transitory increase in rectal temperature that was not clinically important. Terminal elimination half-life after IV administration was 1.20+/-0.78 h, volume of distribution at steady state was 1.51+/-0.39 L/kg, and systemic clearance was 2.09+/-0.62 L/kg/h. Transdermal administration of fentanyl resulted in variable plasma concentrations, with peak plasma concentrations ranging from 1.12 to 16.69 ng/ml (mean+/-SD, 6.99+/-6.03 ng/ml) and time to peak concentration ranging from 8 to 18 hours (mean+/-SD, 13+/-4.5 hours). After removal of the transdermal patch, mean+/-SD terminal elimination half-life was 5.34+/-5.34 hours. CONCLUSIONS AND CLINICAL RELEVANCE: Intravenous administration of fentanyl (2.5 microg/kg) in goats results in a relatively short half-life that will limit its use for management of pain. Transdermal administration of fentanyl (50 microg/h) in goats results in variable plasma concentrations that may exceed those anticipated on the basis of a theoretical delivery rate, but stable plasma concentrations of fentanyl may not be achieved.

Administration, Cutaneous↗
PubMed2004

Effects of transdermal nicotine on prose memory and attention in smokers and nonsmokers.

Previous research investigating cognitive effects of nicotine has produced mixed findings partly due to the use of abstaining smokers and cigarettes as a delivery system. The present study examined effects of nicotine delivered via a transdermal patch on prose memory and sustained attention in male smokers (n=25) and nonsmokers (n=22), who were randomly assigned to either a placebo or a nicotine condition. All groups were matched on their verbal ability and gross personality characteristics (state/trait anxiety levels, extroversion-introversion, and impulsivity level). In the nicotine condition, smokers were treated with a 21-mg transdermal patch, while nonsmokers received a 7-mg nicotine patch. Six hours following patch application, their performance was assessed on a computerized prose memory task and the Rapid Visual Information Processing task (RVIP) in a counterbalanced order and double-blind fashion. The results demonstrated that smokers in the placebo group recalled a significantly greater number of propositions than their counterparts in the nicotine group. Nonsmokers in the nicotine condition also remembered significantly more of the prose material than smokers in the same condition and showed a trend towards better recall of propositions of medium importance in the nicotine condition in comparison to the nonsmokers in the placebo group. No between-group differences were found on the RVIP task. A significant effect of time was found for systolic blood pressure and heart rate. The results cannot be interpreted using the arousal theory of nicotine effects on attention and are explained on the basis of a dose-dependent nicotinic action possibly recruiting cholinergic cortical projections.

Administration, Cutaneous↗
PubMed2005

Transdermal delivery of flurbiprofen: permeation enhancement, design, pharmacokinetic, and pharmacodynamic studies in albino rats.

The enhancing effects of lemon oil on the transdermal penetration of flurbiprofen through rat skin invitro and in vivo was investigated. The maximum flux achieved by Isopropyl alcohol (IPA):Propylene glycol (PG) (70:30% v/v) solvent mixture was further increased by lemon oil. The flux of flurbiprofen through ethylene vinyl acetate microporous membrane was evaluated. The membrane altered the flux of flurbiprofen significantly. The reservoir type of transdermal patch was fabricated using flurbiprofen viscous system, ethylene vinyl acetate membrane, and backing film. Histological investigations were done on rat skin samples treated with solvent systems with or without penetration enhancer for 24 hr. No skin irritation was seen. Lemon oil produced more pronounced change in stratum corneum and the epidermis as compared with the control groups. The pharmacokinetics of flurbiprofen in albino rats following application of a transdermal patch for 24 hr was evaluated. The maximum plasma concentration (C(max)) and AUC(0-alpha) of the patch formulation was 1.7 and 1.6 times, increased respectively as compared with the control patch formulation. Quantity of the drug accumulated in the excised skin to which test patch formulation was applied was more than the one to which control patch formulation was applied. Anti-inflammatory effect in the Carrageenin-induced paw edema in rat was significantly higher than the control patch formulation.

Administration, Cutaneous↗
PubMed2005

Transdermal delivery of imipramine hydrochloride: development and evaluation (in vitro and in vivo) of reservoir gel formulation.

The in vitro permeation studies of imipramine hydrochloride (IMH) reported earlier from our laboratory showed that a combination of menthol (2.5% w/v) and oleic acid (2.5% w/v) worked well in terms of safety and efficacy. The main objective of this study was to evaluate the in vivo performance of this combination; in order to do that, penetration enhancers were incorporated in a hydro-alcoholic gel of hydroxypropylmethyl cellulose along with IMH and used as the drug matrix in a reservoir transdermal patch. A stability study of IMH gel was performed at 40 degrees C/75% RH for 2 months. The results of this study indicate that gels of IMH stored at 40 degrees C/75% RH turned yellow brown in 2 months and the small change in viscosity of gel at 40 degrees C/75% RH had an insignificant effect on the release rate of IMH from the gel (p>0.05). The in vivo performance of the gel was tested in rats using a reservoir transdermal patch, which consisted of a backing membrane, drug matrix and retaining membrane with an area of 12.5 cm2. Plasma concentrations of 3 microg/ml of IMH were achieved and in a histopathological study 24 h occlusion was found to be safe.

Administration, Cutaneous↗
PubMed1993

Nicotine-replacement products in smoking cessation: a review.

Smoking cessation programmes have gained greater prominence in Singapore in the face of growing desire among smokers to stop smoking. There exists a whole plethora of different methods which are employed in smoking cessation; this reflects the fact that smoking is a compulsive habit which is difficult to stop. Most attempts at smoking cessation fail, and the failure is largely attributable to the addictive properties of nicotine, which causes a withdrawal syndrome when the body is deprived of it. A host of medications have been used in the past in an attempt to alleviate this withdrawal syndrome. Of these products, perhaps the most promising are the nicotine-replacement products. These products consist of nicotine which is delivered through contrasting delivery systems viz polacrilex gum, transdermal patches, nasal sprays and inhalers. A review of recent clinical trials assessing the efficacy of the nicotine gum and the transdermal nicotine patch was conducted. Of the two products, the transdermal nicotine patch seems to have superior pharmacokinetics and fewer side-effects, and may well be the product of choice.

Administration, Cutaneous↗