Transdermal Drug Delivery System Project Report - Part3
8. a) CONDITIONS IN WHICH TRANSDERMAL PATCHES ARE USEDTransdermal patch is used when:
(1)When the patient has intolerable side effects (including constipation) and who is unable to take oral medication (dysphagia) and is request requesting an alternative method of drug delivery.
(2) Where the pain control might be improved by reliable administration. This might be useful in patients with cognitive impairment or those who for other reasons are not able to self‐medicate with their analgesia.
3) It can be used in combination with other enhancement strategies to produce synergistic effects.
b) CONDITIONS IN WHICH TRANSDERMAL PATCHES ARE NOTUSED
The use of transdermal patch is not suitable when:
(1) Cure for acute pain is required.
(2) Where rapid dose titration is required.
(3) Where requirement of dose is equal to or less than 30mg/24 hrs.
c) IDEAL REQUIREMENT OF TRANSDERMAL PATCH
• Shelf life up to 2 years
• Small size patch (i.e., less than 40 cm2)
• Convenient dose frequency (i.e., once a day to once a week)
• Cosmetically acceptable (i.e., clear, white color)
9. RECENT ADVANCES IN THE FIELD OF TRANSDERMAL PATCHES
Many research works have been and are few are going on in this field. Few of the latest research done in the field of transdermal patches are stated below:
1. Patch technology for protein delivery
Transdermal delivery of large proteins is a novel and exciting delivery method. There is no commercial technology currently available that incorporates proteins into transdermal patches. TransPharma uses its unique printed patch technology for transdermal delivery of proteins There by complementing its Via Dermdelivery technology.18
Small needle is inserted a few millimeters into skin and drug solution is flowed through the needle into the skin at controlled rates using a micro infusion pump that is contained within a large patch affixed to skin, morphine has been delivered to humans using this approach.
During the past decade several theories have been put forward in addressing the combinations of chemicals and iontophoresis; chemical sand electroporation; chemicals and ultrasound; iontophoresis and ultrasound; electroporation and iontophoresis; and electroporation and ultrasound.
TransPharma is focused on products for which our technology will provide clear benefits over existing therapies. Such benefits could include improving safety and compliance through the use of a drug patch or enhancing efficacy with the use of sustained release patch formulations, among others.
The ViaDerm system may be applied to the delivery of local medications for topical applications in the fields of dermatology and cosmetics. The ViaDerm system may also allow enhanced immunisations, providing a nonpainful, safe and effective alternative to current intramuscular or subcutaneous vaccination methods.
2. Painfree diabetic monitoring using transdermal patches
The first prototype patch measures about 1cm and is made using polymers and thin metallic films. The 5×5 sampling array can be clearly seen, as well as their metallic interconnections. When the seal is compromised, the interstitial fluid, and the biomolecules contained there in, becomes accessible on the skin surface. Utilizing micro heating elements integrated into the structural layer of the patch closest to the skin surface, a high temperature heat pulse can be applied locally, breaching the stratum corneum. During thisablation process, the skin surface experiences temperatures of 130°C for 30m duration. The temperature diminishes rapidly from the skin surface and neither the living tissue nor the nerve ending sare affected.19 This painless and bloodless process results indisruption of a 4050μm diameter region of the dead skin layer, approximately the size of a hair follicle, allowing the interstitial fluid to interact with the patch's electrode sites.
3. Testosterone transdermal patch system in young women with spontaneous premature ovarian failure
In premenopausal women, the daily testosterone production is approximately 300 µg, of which approximately half is derived from the ovaries and half from the adrenal glands. Young women with spontaneous premature ovarian failure (sPOF) may have lower androgen levels compared with normal ovulatory women. Testosterone transdermal patch (TTP) was designed to deliver the normal ovarian production rate of testosterone. The addition of TTP to cyclic E2/MPA therapy in women with SPOF produced mean free testosterone levels that approximate the upper limit of normal.
4. Pain relief
Pain relief routinely benefits from transdermal patch technology. Most of the readers are aware of the Duragesic patch. There are several others now on the market. One is Lidoderm, a lidocaine 5percent patch, which is used for post herpetic neuralgia. Other exciting advancements in pain control include the E‐Trans fentanyl HCl patch.
10. FUTURE TECHNOLOGIES AND APPROACHES
Thermal Poration is the formation of aqueous pathways acrossstratum corneum by the application of pulsed heat, thisapproach has been used to deliver conventional drugs and to extract intestinal fluid glucose from human subjects.
Jet injectors are receiving increased attention now days, which is opening doors for improved device design for controlled, needle free injection of drug solutions solutions across the skin and into deeper tissue.
Small needle is inserted a few millimeters into skin and drugsolution is flowed through the needle into the skin at controlledrates using a microinfusion pump that is contained within alarge patch affixed to skin, morphine has been delivered tohumans using this approach.
During the past decade several theories have been put forwardin addressing the combinations ofchemicals and iontophoresis;chemicals and electroporation; chemicals and ultrasound;iontophoresis and ultrasound; electroporation andiontophoresis; and electroporation and ultrasound.
TransPharma is focused on products for which our technologywill provide clear benefits over existing therapies. Suchbenefits could include improving safety and compliance through the use of a drug patch or enhancing efficacy with theuse of sustained release patch formulation, among others.
The ViaDerm system may be applied to the delivery of localmedications for topical applications in the fields ofdermatology and cosmetics. The ViaDerm system may also allowenhanced immunisations, providing a nonpainful, safeand effective alternative to
current intramuscular orsubcutaneous vaccination methods.
Altea Therapeutics is currently in clinical development of atransdermal patch designed to address a major unmet need bypreventing ‘off’ periods and provide an improved therapeutic option for managing Parkinson’s disease.
11. CONCLUSION
A lot of progress has been done in the field of Transdermal Patches. Due to large advantages of the Transdermal Drug Delivery System, this system interests a lot of researchers. Many new researches are going on in the present day to incorporate newer drugs via this system. Various devices which help in increasing the rate of absorption and penetration of the drug are also being studied.
However, in the present time due to certain disadvantages like large drug molecules cannot be delivered, large dose cannot be given, the rate of absorption of the drug is less, skin irritation, and etc the use of the Transdermal Drug Delivery System has been limited. But, with the invention of the new devices and new drugs which can be incorporated via this system, it used is increasing rapidly in the present time.
This article provide an valuable information regarding the transdermal drug delivery systems and its evaluation process details as a ready reference for the research scientist who are involved in TDDS. The foregoing shows that TDDS have great potentials, being able to use for both hydrophobic and hydrophilic active substance into promising deliverable drugs. To optimize this drug delivery system, greater understanding of the different mechanisms of biological interactions, and polymer are required. TDDS a realistic practical application as the next generation of drug delivery system.