Microprocessor in controlled transdermal drug delivery of anti-cancer drugs.

Microprocessor controlled transdermal delivery of anticancer drugs 5-Fluorouracil (5-FU) and 6-Mercaptopurine (6-MP) was developed and in vitro evaluation was done. Drugs were loaded based on the pharmacokinetics parameters. In vitro diffusion studies were carried at different current density (0.0, 0.1, 0.22, 0.50 mA/cm2). The patches were evaluated for the drug content, thickness, weight, folding endurance, flatness, thumb tack test and adhesive properties all were well with in the specification of transdermal patches with elegant and transparent in appearance. In vitro permeation studies through human cadaver skin showed, passive delivery (0.0 mA/cm2) of 6-MP was low. As the current density was progressively increased, the flux also increased. the flux also increased with 0.1 mA/cm2 for 15-20 min, but it was less than desired flux, 0.2 mA/cm2 for 30 min showed better flux than 0.1 mA/cm2 current, but lag time was more than 4 h, 0.5 mA/cm2 current for more than 1 h, flux was >159 microg/cm2 h which was desired flux for 6-MP. 5-FU flux reached the minimum effective concentration (MEC) of 54 microg/cm2 h with 0.5 mA/cm2 current for 30-45 min, drug concentration were within the therapeutic window in post-current phase. We concluded from Ohm's Law that as the resistance decreases, current increases. Skin resistance decrease with increase in time and current, increase in the drug permeation. Interestingly, for all investigated current densities, as soon as the current was switched off, 5-FU and 6-MP flux decreased fairly, but the controlled drug delivery can be achieved by switching the current for required period of time.

Clinical evaluation of 5-fluorouracil from transdermal patches on EAC and DLA cell-induced tumors in mice.

The aim of the present study was formulate and clinically evaluate 5-fluorouracil (5-FU) transdermal patches. Cytotoxicity was measured by exposing cell suspensions to increasing concentrations of drug from 10-100 microg/ml and performing viable cell counts by the trypan blue exclusion method. Results confirmed 100 infinity g/ml and 50 microg/ ml of 5-FU to be cytotoxic to EAC and DLA cells. In mice, increase in the life span (ILS) by 87.1% with a maximum survival time of 30.5+/-1.87 days was found with EAC cell-induced tumors, with an ILS of 88.1% and a maximum survival time of 39.5+/-1.87 days for DLA cell-induced lesions with 5-FU transdermal patches. The results were statistically significant (p<0.01) compared to untreated controls. Pharmacokinetic studies in rabbits showed a t1/2 of 29+/-6 min, a Cmax (ng/ml) of 978.23, an AUC0-infinity (ng/ml/h) of 1213.73 +/-14 and a Tmax (h) of 0.5. 5-FU from transdermal patches exhibited a half-life of 95+/-0.5 min, a Cmax (ng/ml) of 863.25, an AUC0-infinity (ng/ml/h) of 1567+/-36 and a Tmax (h) of 1.5. Velcro protection jackets proved suitable in this study to stop mice licking, scratching and rubbing applied patches.

In vivo immunomodulatory, cumulative skin irritation, sensitization and effect of d-limonene on permeation of 6-mercaptopurine through transdermal drug delivery.

Using skin as a port for systemic drug administration, transdermal drug delivery has expanded greatly over the last two decades. Our aim was to formulate the single layer drug-in-adhesive transdermal patch for 6-mercaptopurine (6-MP). In vitro permeation study was carried out using modified Franz diffusion cell with and without of different concentration of d-limonene in human cadaver skin. In vivo immunomodulatory was carried out in mice, cumulative skin irritation, sensitization and patch adherence study was done in both mice and human subjects. 6-MP flux increased from 43+/-12.2 microg/cm2h (control) to 162.8+/-32.2 microg/cm2h (6% w/v d-limonene) data was significant (p<0.05), with decrease in the lag time to 35+/-9.3 min compared to control of 90 +/-15.3 min. In vivo immunomodulatory effect was shown in the Balb/c mice with 100 mumol/kg/body wt of animal for 5d (one dose/d) of d-limonene. WBC count of 13469 cells/mm peak was observed on 12th day, bone marrow cells of 26.3 x 10(6) cells/femur and alpha-esterase positive cells of 1259+/-328.4 cells/4000 bone marrow cells. Cumulative skin irritation, sensitisation and patch adherence in animals and human subjects showed no skin irritation and sensitization. Patch adhesion was greater than 90.0% respectively in both human subjects and mice. The percentage of human subjects with adhesive residue was significantly less with scores of zero. d-Limonene proved as good chemical enhancer by increasing in the skin permeability with shortened the lag time. It proved that therapeutic amount of 6-MP can be delivered through transdermal drug delivery.

Physicochemical and pharmacokinetic parameters in drug selection and loading for transdermal drug delivery.

Skin of an average adult body covers a surface of approximately 2 m2 and receives about one-third of the blood circulating through the body. The transdermal route of administration cannot be employed for a large number of drugs. The rationality of drug selection based on pharmacokinetic parameters and physicochemical properties of the drug are the important factors to be considered for deciding its suitability of drug for delivery by transdermal route.

Microprocessor-controlled iontophoretic drug delivery of 5-fluorouracil: pharmacodynamic and pharmacokinetic study.

PURPOSE: The purpose of this study was to fabricate monolithic 5-fluorouracil (5-FU) transdermal patch with microprocessor- controlled iontophoretic delivery, to evaluate the pharmacodynamic effects on Dalton's lymphoma ascites (DLA) induced in Balb/c mice, and to study pharmacokinetics in rabbits. MATERIALS AND METHODS: The transdermal patches were prepared by solvent casting method; a reprogrammable microprocessor was developed and connected to the patches. DLA cells were injected to the hind limb of Balb/c mice (10 animals/group). In the first group of mice 5-FU was administered i.v. (12 mg/kg). In the second group of mice, transdermal patches (20 mg/patch/animal) were installed and kept for 10 consecutive days, while the third (control) group was kept without any treatment. The tumor diameter was measured every 5th day for 30 days, and the animal survival time and death pattern were studied. The electric current density protocol of 0.5 mA/cm(2) for 30 min was used in the pharmacokinetic study in rabbits. RESULTS: There was a significant reduction in tumor volume in the animals treated with monolithic matrix 5-FU transdermal patch compared to untreated controls and i.v. therapy. Tumor volume of the control animals was 5.8 cm(3) on the 30th day, while in 5-FU with transdermal patch delivery animals it was only 0.23 cm(3) (p <0.05). DLA cells tumor-bearing mice treated with 5-FU with transdermal patch had significantly increased lifespan (ILS). Control animals survived only 21+/-1 days after the tumor inoculation, while i.v. 5-FU and 5-FU patches animals survived 24+/-2.7 days and 39.5+/-1.87 days with ILS of 25.58% and 88.09%, respectively (p <0.01). There was significant sustained release of 5-FU through microprocessor-controlled patches and half-life was significantly higher (p <0.05) compared to the i.v. route. CONCLUSION: Cytotoxic concentration of 5-FU can be achieved through the transdermal drug delivery and effective therapeutic drug concentration can be maintained up to 24 h, with less toxicity. A new generation of transdermal drug delivery systems based on microprocessor-controlled iontophoresis is in the late stages of development and promises to enhance the treatment of local and systemic medical conditions. The incorporation of microprocessor into these systems has been an important advancement to ensure safe and efficient administration of a wide variety of drugs.

Transdermal delivery of 5-fluorouracil for induced ehrlich ascites carcinoma tumor in BALB/c mice and pharmacokinetic study.

The purpose of this study was to determine the permeation of the hydrophilic compound 5-fluorouracil through human epidermal membranes, Ehrlich Ascites Carcinoma (EAC) cells were used as a model cell line to evaluate the cytotoxic concentration and anti-tumor activity of 5-fluorouracil (5-FU) through transdermal drug delivery for tumors. Cytotoxicity was assessed by exposing cell suspension to increased concentration of drug from 20-100 microg/ml and measuring the viable cell count by tryphan blue exclusion method. Results confirmed that 100 microg/ml of 5-FU was cytotoxic. The increase in the life span (ILS) was 87.05% with maximum survival time of 30.5+/-1.87 days. For 5-fluorouracil monolithic matrix transdermal patch, the results were statistically significant (p<0.05) compared to untreated control, anti-tumor activity was very effective compared to intravenous therapy. Patches did not show any sign of erythema, vesiculations or bullaous reaction. Mean cumulative skin irritation and adherence scoring for both animal and humans proved that none of the irritation sensitization reactions score were zero and less than one, while good adherence score was 0, with complete adherence to the skin, without leaving any adhesive residue on skin with scores = 0 in human subjects. Transdermal patches showed 100% flatness, thickness 150+/-0.03 mm, good content uniformity, folding endurance (>500 foldings), smoothness, transparency, flexibility and appearance. Pharmacokinetic studies of 5-FU transdermal patch in rabbits showed half-life 95+/-0.5 min, C(max) (ng/ml) 863.25,AUC(0-infinity) (ng/ml/h)1567+/-36 and T(max) (h) 1.5 with controlled release for 24 h which was very significant (p<0.001) compared to intravenous route. Recent patents has been reported for suitable treatment of tumors and cancer, by topical and transdermal applications. Velcro protection jackets were suitable for this study and protected our applied transdermal patched from being licked, scratched and rubbed off.