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We tested the efficacy of scopolamine delivered by transdermal patch in preventing emesis induced by cisplatin as a single agent or in combination. The administration of scopolamine by transdermal patch resulted in acceptable side effects but was ineffective in controlling cisplatin-induced emesis.
Alternatives to oral estrogen replacement, including the transdermal patch, deliver estradiol in a constant manner, produce more physiologic estrone and estradiol levels than oral therapy, and avoid the first-pass effect on hepatic protein synthesis. Transdermal patches and estradiol implants have been demonstrated to produce favorable lipid profiles, prevent bone loss, relieve vasomotor symptoms, and improve urogenital atrophy. Vaginal estrogen is an effective treatment for vaginal atrophy. The advantages and disadvantages of each of the hormonal alternatives to oral estrogen replacement are discussed.
The present research was designed to evaluate different matrix, drug-in-adhesive and reservoir formulations of fentanyl transdermal patches. The target was to design drug-in-adhesive patches (DIAPs); a full factorial design was used. Different types and amounts of liquid, pressure-sensitive adhesives (PSAs) were used and evaluated with respect to drug release and adhesive properties. A very simple but precise method, the simplified peel 180 degrees test, was developed to measure and compare adhesive properties of transdermal patches. The results showed that release kinetics obeyed the square root of time or Higuchi model, indicating the diffusion controlled release mechanism. It was found that the amount of fentanyl needed for each 10 cm(2) three-days DIAP should be 3.3 mg. The respective amounts for reservoir and matrix patches were 2.5 and 5 mg. It was concluded that acrylic PSAs showed the best adhesion and release properties.
The pharmacokinetic patterns of estradiol (CAS 50-28-2) and of estrone (CAS 53-16-7) were investigated in 18 women in natural or surgical menopause during the application of a new estradiol transdermal patch with active matrix and without absorption enhancers designed for epicutaneous applications of 7 days (hereinafter called "patch 7D"). The study was made with randomized and balanced sequences of applications in cross-over of either patch 7D or of an authorized estradiol transdermal patch with a nominal release rate of 50 micrograms/day estradiol designed for a twice-a-week epicutaneous application (hereinafter called "patch 50"). The sequences consisted of applications for 3 weeks either of 3 patches 7D or of 6 patches 50. The patches were applied on the skin of the hips or upper buttocks. The serum samples were obtained during the 1st and during the last week of application of the patches. Estradiol (E2) was assayed in serum by a double-antibody RIA method selective for free estradiol. Estrone (E1) was assayed in serum using a 3H-estrone RIA method. The steady state with regard to E2 and E1 was achieved already during the application of the 2nd patch. Patch 7D provided within 6 h an increase of the E2 concentrations in serum from the basal postmenopausal level of less than 3 pg/ml to therapeutically effective concentrations. The Cmax of E2 of 45 pg/ml was reached on average after 25 h, the concentrations of E2 remaining at sustained and therapeutically effective levels during the whole application of patch 7D. At steady state, during the 3rd week of application, the Cav was on average 31 pg/ml. With a small delay, E1 also increased from the basal 15 pg/ml to a Cmax of 41 pg/ml after 44 h. At steady state, during the 3rd week of application, the Cav was on average 38 pg/ml. Patch 7D provided a similar bioavailability as patch 50 with regard to the rate and the extent of absorption of E2, as shown by the AUCs during the 7-day applications of one patch 7D compared to those during the 7-day applications of 2 patches 50. The release of E2 from patch 7D is therefore similar to that of patch 50, i.e. on an average of 50 micrograms/day over a 7-day period of application. The E2/E1 ratio increased from the postmenopausal values lower than 0.2 found before the application of patch 7D to average values of 0.67, i.e., to values that are normally found during the fertile life of the woman. The improvement of the E2/E1 ratio occurred already in the first 6-12 h of application of patch 7D. The E2/E1 ratio returned rapidly to the initial low postmenopausal levels after removal of the patch. Patch 7D was well tolerated by the skin, probably because it does not contain absorption enhancers. It provoked, however, some systemic adverse reactions typical of E2 overdosing. In the therapeutic practice these adverse reactions can easily be avoided using patches 7D of lower strength. No drop-out due to systemic or local intolerance occurred. The adhesion of patch 7D on the skin was good. During the application of a total of 54 patches, only in one occasion one patch became partially detached (about 40% of the total area) from the 3rd to the 7th day during the first 7-day period of application.
OBJECTIVE: An observation of an influence of long-term therapy of pregnant women affected by arterial hypertension with transdermal patches releasing GTN on stabilisation of blood pressure and newborn condition. STUDY DESIGN: The transdermal patches (Minitran S10) releasing GTN were used for the treatment of 27 pregnancies between 27-34 weeks admitted for hypertension above 150/100 mmHg. The average period of obtaining the proper blood pressure values, time of therapy, side effects of treatment and effects of nitrate tolerance were assessed. After delivery the newborns condition were estimated by Apgar score and their trophy was assessed after the centile chart. RESULTS: The diminishing of mean blood pressure values in range 135/85 mmHg was received after 8 to 48 hours of treatment in 25 of the examined women. The time of therapy was from 3 to 13 weeks without any serious side effects besides transient headaches eliminated by application of oral analgesic drugs. 24 newborns were delivered in good conditions--8-9 Apgar score. No side effects of long-term therapy with patches releasing GTN were observed among the newborns. CONCLUSIONS: The long-term transdermal treatment afford possibilities for pregnancy prolongation until the term of delivery and improves the foetal development conditions. The side effects of treatment are transient and affected only mothers.
A study of the urinary concentration of fentanyl (F) and its major metabolite norfentanyl (NF) in chronic pain patients treated with the Duragesic continuous release transdermal patches is presented. These patches are available in 10, 20, 30, and 40 cm(2) sizes releasing 25, 50, 75, and 100 microg/h F, respectively. F is rapidly and extensively metabolized, with NF as the major metabolite. Five hundred-forty six random urine specimens were collected from chronic pain patients wearing 25, 50, 75, or 100 ug F transdermal patches. Urine specimens were collected from hours after application to several days later after continuous F release. Each specimen was analyzed for F, NF, creatinine, and pH. Additionally, each was screened by enzyme immunoassay for the following: amphetamines, barbiturates, benzodiazepines, cocaine metabolite, methadone, phencyclidine, d-propoxyphene, opiates, and marijuana metabolites. All positive screening results were confirmed by gas chromatography-mass spectrometry (GC-MS). F and NF were isolated from urine by solid-phase extraction then identified and quantified by GC-MS in SIM mode. The LODs and LOQs for F and NF were 3 ng/mL, respectively. The results of F and NF analysis of urine form those wearing 25-microg patches (N = 142) was mean F, 47 ng/mL with a range of 0 to 983 ng/mL, and 97% of the specimens contained < 200 ng/mL and mean NF, 175 ng/mL with a range of 0-980 ng/mL, while 95% of the specimens contained < 400 ng/mL. The results of F and NF analysis of urine form those wearing 50 microg patches (N = 184) was: mean F, 74 ng/mL with a range of 0 to 589 ng/mL, and 92% of the specimens contained < 200 ng/mL and mean NF, 257 ng/mL with a range of 0-2200 ng/mL, and 98% of the specimens contained < 1000 ng/mL. The results of F and NF analysis of urine form those wearing 75 microg patches (N = 85) was mean F, 107 ng/mL with a range of 0 to 1280 ng/mL, and 98% of the specimens contained < 400 ng/mL and mean NF, 328 ng/mL with a range of 0-5630 ng/mL, and 99% of the specimens contained < 1000 ng/mL. The results of F and NF analysis of urine form those wearing 100 ug patches (N = 135) was mean F, 100 ng/mL with a range of 0 to 1080 ng/mL, while 96% of the specimens contained < 400 ng/mL and mean NF, 373 ng/mL with a range of 0-5730 ng/mL, and 95% of the specimens contained < 1000 ng/mL. The incidence of other drugs detected as a percentage the specimens was opiates, 48%, benzodiazepines, 43%; barbiturates, 3%; methadone, 4%; marijuana metabolite, 3%; and cocaine metabolite, 1%. With the exception of F and/or NF, no other drugs were detected in 25% of the specimens. These data demonstrate the wide variation in concentrations of F and NF in random urine specimens following application of Duragesic patches. However, these values obtained during therapeutic use far exceed concentrations previously reported in fatal poisoning. In general, one may expect to find urine NF concentrations 3-4 times higher than those of F.
OBJECTIVE: To compare the costs and outcomes of treating exercise-induced angina with once- or twice-daily isosorbide mononitrate (ISMN) or transdermal patch. METHOD: A decision-analytic model was designed based on published literature showing compliance and increasing symptoms and estimates from physicians on treatment patterns and worsening symptoms. RESULTS: Data show that patients are more compliant with once-daily ISMN (Imdur, Astra Hässle, Mölndal, Sweden) and patch regimens than with twice-daily dose. Based upon the assumption that more compliant patients are better controlled, the model found that fewer medical care resources were consumed by patients treated with the once-daily and the patch regimens. The unit cost of the twice-daily ISMN regimen is 40% of the unit cost of the once-daily. Annual costs of treating an exercise-induced angina patient are 248 pounds for Imdur compared to 250 pounds for the twice-daily ISMN and 299 pounds for the transdermal patch. CONCLUSION: Unit prices alone are not good indicators for estimating medical management costs.
The experimental models and the studies in man employed to assess the skin and general safety of a newly developed glyceryl trinitrate (GTN, CAS 55-63-0) transdermal patch, hereinafter coded EPI, are described. EPI was found well tolerated by the skin after single or 28-day repeated epicutaneous application on the rabbit, devoid of phototoxicity in the mouse, devoid of skin sensitizing potential in the guinea pig and devoid of photosensitizing effects in the guinea pig. Tested were also, with negative results, the cytotoxic, hemolytic and genotoxic potential, the presence of bacterial endotoxins, the systemic and intracutaneous toxicity, and the possible conjunctival irritant effects. The application of EPI for 14 consecutive days on the thoracic skin of 28 healthy volunteers did not provoke subjective discomfort such as itching, burning or pain, or objective skin lesions. On the application site a light and transient erythema was often found demonstrating the transcutaneous absorption of the vasodilating GTN from the patch. The 14-day application was followed after two weeks by the application of a challenge EPI patch to detect a possible skin sensitization by EPI. No skin reaction was elicited, showing that also in man EPI is devoid of skin sensitizing potential. During the 14-day application of EPI several GTN commonly induced systemic adverse reactions were observed, particularly headache, confirming the systemic bioavailability of GTN from the patch. Headache rapidly disappeared after removal of the patch, in parallel with the decrease of the blood concentrations of GTN and of its active metabolites, consistently with the previous pharmacokinetic findings. This is an advantage of the administration of GTN with the transdermal patch because, in the case of unbearable headache, the patient is relieved by the simple removal of the patch.
A case of infant clonidine poisoning from a transdermal patch that had been worn for five days by an adult and then discarded is described. The infant became hypotensive with a systolic blood pressure of 38 mm Hg, and a dopamine infusion was required for six hours to maintain adequate blood pressure. The infant was discharged 24 hours after admission. Clonidine toxicity, transdermal delivery system pharmacokinetics, and poison prevention are discussed.
Nicotine transdermal patches (NTPs) were fabricated using an acrylic pressure sensitive adhesive emulsion to form a transparent matrix film. An automated thin layer chromatography (TLC) plate scraper was used to control the thickness of the cast nicotine matrix film. The in vitro release behavior and permeation of nicotine across abdominal human epidermis (HE) from the NTPs was studied using United States Pharmacopeia (USP) dissolution apparatus 5 (paddle over disk) and modified Franz-diffusion cell, respectively. The release of nicotine from the NTPs showed a good linear correlation with the square root of time (R2 > 0.99). This indicated a matrix diffusion controlled-release mechanism. The surface morphology of the matrix of the NTP was uniform and nonporous before and after release, indicating that the dried adhesive nicotine matrix was a homogeneous single-phase film. Neither the nicotine content in the range 4.70-8.41% w/w nor the film thicknesses of the NTPs affected the apparent diffusion coefficient of nicotine in the acrylic matrix. A good relationship between the amount of nicotine permeated across the HE and the square root of time was also observed with R2 > 0.98. This study also showed that the NTPs provided a good delivery system with more than 65% of the nicotine delivery being controlled by the device. Moreover, the release of nicotine from six production batches met the criteria of USP 24. This finding presented a good potential of this method for upscaling to industrial manufacturing.
OBJECTIVE: To determine the efficacy of the transdermal nicotine patch for smoking cessation in inner-city African Americans. DESIGN: Double-blind, placebo-controlled, randomized trial. SETTING: Outpatient in an inner-city hospital. PATIENTS AND PARTICIPANTS: A computer-generated random numbers table with a block size set at 20 was used to randomize 410 patients to one of two study arms. INTERVENTIONS: The transdermal nicotine patch for 10 weeks as an adjunct to brief counseling. MEASUREMENTS AND MAIN RESULTS: Of the 410 patients randomized, mean age was 48 years, 65% were female, 41% had less than a high school education, 51% had an annual household income of less than $8,000, and the average number of cigarettes smoked per day was 20. Quit rates at 10 weeks were 21.5% (44/205) with the nicotine patch, and 13.7% (28/205) with the placebo patch (p = .03). At 6 months, quit rates were 17.1% (35/205) with the nicotine patch, and 11.7% (24/205) with the placebo patch (p = .08). After adjusting for baseline differences in age and educational attainment, differences remained significant at 10 weeks (p = .04), but were not significant at 6 months (p = .14). Compliance rates for return visits were 83%, 78%, 55%, and 52%, at 1, 2, 6, and 10 weeks, respectively. CONCLUSIONS: The nicotine patch significantly improves short-term quit rates in inner-city African Americans who are interested in trying to quit smoking. Efforts should be made to reach underserved populations through smoking cessation programs, and to assist in maintaining abstinence.
The transferred percentages of 13 drugs to rat skin from transdermal patches were studied to reveal the relationship to their physicochemical properties. The drugs to be tested had melting points of 13.5-234 degrees C, lipophilic indices of 0.475-5.336, and molecular weights of 122.12-392.45. The transferred percentage of drug to intact skin was lower, the higher the melting point, lipophilic index and molecular weight. The same was true in stripped skin, where the transferred percentage of drug was markedly increased. The difference between transferred drug percentages to stripped and intact skin, which could be regarded as the regulatory contribution of the stratum corneum, tended to be larger, the lower the drug's melting point and lipophilic index.
To select a suitable formulation for the development of transdermal drug-delivery system of diltiazem hydrochloride. Transdermal patches of the drug, employing different ratios of polymers, ethylcellulose (EC), and povidone (PVP) were developed and evaluated for the potential drug delivery using depilated freshly excised abdominal mouse skin. The influence of different film compositions on in vitro drug permeation into receptor fluid were studied using a modified Franz diffusion cell. The cumulative amount of drug was found to be proportional to the square root of time, i.e., Higuchi kinetics. From this study, it was concluded that the films composed of povidone:ethylcellulose (1:2) should be selected for the development of transdermal drug-delivery system of diltiazem hydrochloride, using a suitable adhesive layer and backing membrane, for potential therapeutic use.
The pharmaceutical development and characteristics of the new glyceryl trinitrate (GTN, CAS 55-63-0) transdermal patch Epinitril, hereinafter called EPI, are described. EPI is a thin (0.096 mm), transparent patch, with GTN uniformly dissolved in a monolayer pressure-sensitive acrylates vinyl acetate copolymer adhesive matrix. The patch provides an intense flux rate of GTN through the skin (33 micrograms/cm2/h). This is the result of the high concentration of GTN in the matrix (39.3% w/w) and of its thinness (0.033 mm), which elicit a high thermodynamic activity of GTN on the surface of the skin, promoting its absorption. EPI was developed in three strengths with release rates of 5, 10 and 15 mg GTN in 24 h, to allow the adaptation of the dose to the needs of the individual patient. During development, different tests were used to evaluate in vitro the release of GTN, i.e. a) the disk assembly dissolution test, b) the artificial membrane-controlled dissolution test and c) the diffusion test through the stratum corneum and epidermis of human skin. None was able to provide a reliable in vitro-in vivo correlation of the performance of the investigated patches. The tests, however, are useful to evaluate the effects of formulation changes during pharmaceutical development. For its small size, thinness, flexibility, transparency, easiness of application and of removal and for its good tolerability, EPI is very patient friendly, a quality that improves the compliance with the long-term therapeutic courses needed in angina pectoris.
The present study was undertaken to prepare and evaluate monolithic drug-inadhesive type transdermal patches of melatonin containing penetration enhancers such as fatty alcohols, fatty acids, and terpenes. The patches were prepared using Eudragit E 100 as the adhesive polymer. The release profile of melatonin from control as well as enhancer-containing patches showed an initial burst of melatonin release for up to 4 hours and then a plateau after 8 hours. The release profiles of melatonin from patches containing various enhancers were similar to the control patch. However, the addition of enhancers in the patch increased the permeation of melatonin through hairless rat skin. The flux values of patches containing octanol, nonanoic acid, and myristic acid were higher than the control patch (no enhancer), but the differences were not statistically significant (P>0.05). Decanol, myristyl alcohol, and undecanoic acid at 5% concentrations showed significantly higher flux values through hairless rat skin (enhancement ratios 1.7, 1.5, and 1.6 for decanol, myristyl alcohol, and undecanoic acid, respectively) (P<0.05). Menthol and limonene at 5% w/w showed maximum permeation of melatonin among all enhancers studied (enhancement ratios=2.1 and 2.0 for menthol and limonene, respectively) (P<0.001). In general, there was about 4-6 hours of lag time observed before a steady state flux of melatonin was achieved. Though the flux of melatonin observed in the present study is 5-10 times higher than the required delivery rate in humans, it must be noted that the present study was performed using hairless rat skin, which is generally more permeable compared to human skin. Further studies using human skin would prove the usefulness of these patches.
Just over two years ago, it was forecast that transdermal patches would be one of the fastest growing sectors of the drug delivery market. Has the promise of new technology been fulfilled or do pills and potions taken orally still dominate the market? This review will look at the most recent developments and update the technology roadmaps in this US dollar 40-billion market.
The bronchodilating activity and the ability of broxaterol transdermal patch to inhibit bronchial constriction in response to distilled water mist (UNH2O) inhalation were assessed. The study was performed in 10 asthmatic patients in clinical remission according to a placebo-controlled, double-blind, randomized crossover design. Test medications were broxaterol patch (size = 1.75 cm2; programmed delivery = 105 mcg/h) and a matched placebo patch. A spirometric examination was performed before patch application (at 8:30-9:00 a.m.) and 24 hours later. Immediately afterwards, the UNH2O inhalation test was made, consisting of 3 bronchial exposures lasting 30, 60 and 120 s respectively with 3-minute intervals between challenges. Immediately after each exposure, a spirometric examination and specific airway resistance measurements were made. The results obtained show that broxaterol patch exerts a statistically significant bronchodilating effect and has a better protective effect than placebo patch on UNH2O-induced bronchial constriction. The local tolerability of patches was very good. Slight tremors were observed in some subjects.
OBJECTIVES: To compare the absorption of estradiol from a transdermal gel and a novel matrix-type patch and to study the variability in absorption. METHODS: Twenty-four healthy postmenopausal women were treated in an open, randomized, cross-over study for 18 days with 1.0 mg estradiol daily as a transdermal gel and a transdermal patch releasing estradiol 50 microg/24 h without a wash-out between the periods. Venous blood samples for estradiol pharmacokinetics were taken on the 15th and 18th study days of the gel period and during the 15th-18th study days during the patch period. RESULTS: There was no significant difference in peak estradiol level or area under the estradiol time-concentration curve between the gel and the patch. However, trough estradiol concentration was significantly lower and fluctuation higher with the patch. Estradiol time-concentration curves on the 15th and 18th study days with the gel were almost superimposable. A significant difference was observed in peak estradiol levels, whereas area under the curve or trough estradiol level did not differ between the 15th and 18th study days with the gel. Inter- and intra-individual coefficients of variability were around 30% for peak estradiol level and area under the curve, except for the intra-individual coefficient of variability for area under the curve (21%) for the gel. The total coefficient of variability for area under the curve was 35% for the gel and 39% for the patch. CONCLUSIONS: A daily 1.0 mg estradiol dose as a transdermal gel seems to correspond with a matrix-type patch releasing 50 microg estradiol daily in the extent of estradiol absorption. High variability was associated with both treatments, and both the variabilities within and between the subjects were high with the gel. Wider than generally applied confidence limits should be applied for bioequivalence testing of transdermal estradiol formulations.