Transdermal Medication Research Articles

Transdermal medication exchange: the case of the light-headed lover

Transdermal medication exchange: the case of the light-headed lover

Enhancement effects in the permeation of Alprazolam through hairless mouse skin

Alprazolam (ALP) is an anxiolytic, antidepressant agent, having suitable features for the development of a transdermal medication. The objectives of this preliminary study were to determine: (a) whether ALP is absorbed in vitro through hairless mouse skin; (b) whether it is metabolized during diffusion, and (c) the influence of some chemicals on ALP penetration through skin. ALP permeates through hairless mouse skin in vitro. No degradation product of the drug resulted during skin permeation experiments, therefore, ALP was assumed to diffuse unchanged across the skin. Oleic acid (OLA), linoleic acid (LNA), linoleic acid diethanolamide (LNDA), coconut fatty acid diethanolamide (CNDA), lauric acid diethanolamide (LRDA), bis(2-hydroxuethyl)cocamine (HECA) and isopropyl lanolate (IPL) were evaluated with respect to their skin-permeation enhancing effect either as neat solvents or combined with propylene glycol (PG). All the vehicles excepting IPL and PG were more effective than OLA in enhancing transdermal absorption of ALP. The most effective was HECA followed by LNDA, CNDA and LNA/PG (8.5:1.5, w/w). The effects of skin pretreatment with HECA, LNA, LNDA and CNDA on the percutaneous absorption of ALP from a drug suspension in IPL were also investigated. For all the pretreatment vehicles ALP flux from IPL through pretreated skin was greater than that from IPL or OLA through untreated skin. In order to facilitate the interpretation of the absorption results, the stratum corneum/water, whole skin/water and n-octanol/water partition coefficients of the drug were determined.

Patient acceptance of transdermal clonidine. A retrospective review of 25 patients.

The clinical records of 25 ambulatory patients who received clonidine (Catapres-TTS) for periods of one to 19 months were reviewed to determine the effectiveness and long-term patient tolerance of this transdermal antihypertensive medication. In 11 patients with mild to moderate hypertension in whom Catapres-TTS was initiated as monotherapy or added to an oral diuretic, significant blood pressure reduction was observed during the initial four weeks of therapy. In 14 patients who had more severe hypertension and who were receiving multiple antihypertensive agents, Catapres-TTS did not result in significantly reduced blood pressure. Daily home blood pressure measurements in five patients showed no day-to-day variations in blood pressure during the seven days each patch was worn. Catapres-TTS was discontinued in 11 patients because of localized contact dermatitis (six patients), patient dissatisfaction (three patients), and physician's decision (two patients). In three patients, localized contact dermatitis developed only after continuous use for periods of four to 13 months. Other adverse effects such as drowsiness and dry mouth were less apparent than with comparable doses of oral clonidine, and did not necessitate discontinuation of therapy in any patient. Black patients appear to tolerate Catapres-TTS better than whites. Catapres-TTS appears to be effective in patients with mild to moderate hypertension and may be a useful alternative to oral clonidine in patients experiencing drowsiness or dry mouth with the oral preparation.

Dosage From Transdermal Nitroglycerin Pads

To the Editor.— An error appeared in an article on transdermal medications in the MEDICAL NEWS section 1 regarding Searle's Nitrodisc pads. Originally, the descriptions of the two Nitrodisc dosage strengths were based on the fact that the pads contained either 16 or 32 mg of nitroglycerin within the polymer matrix. The descriptions were subsequently changed to 5 mg/24 hr and 10 mg/24 hr, clarifying that 5 and 10 mg of nitroglycerin (respectively0 are released in vivo per 24 hours. The erroneous 11.2 mg/24 hr figure cited in the MEDICAL NEWS item, which is credited to an American Journal of Hospital Pharmacy article, 2 is evidence that some potential for confusion still exists. Although a correction was printed as a letter to the editor in a later issue of the same journal, 3 many physicians are yet unaware that Nitrodisc (10 mg/24 hr) delivers on an average the same amount

Transdermal Medications vs. Medicated Plasters

Transdermal Medications vs. Medicated Plasters