Acne is a common disease characterised by follicular hyperkeratinisation, bacterial hipercolonisation as well as immune reactions and inflammation. In acne, reactive oxygen species (ROS) may be released from the damaged follicular walls, which could cause the advancement of inflammation in the pathogenesis of the disease. The topical application of antioxidants is a promising approach to support the endogenous antioxidant defence and avoid oxidative injury that may lead to acne. The skin provides a painless and patient-friendly approach for systemic drug administration. Transdermal drug delivery not only improves patient compliance, but also avoids the first-pass effect. The major hurdle to penetration of matter through the skin is provided by an outward layer of the skin, the stratum corneurm (SC). Overcoming this barrier safely and reversibly is a fundamental problem in the field of transdermal drug delivery. Alpha-lipoic acid was utilised as the cosmeceutical active and can be classified in a mixed category of compounds that lie between cosmetics and drugs. Alpha-lipoic acid and its reduced form, dihydrolipoic acid, have been described as the "universal antioxidants" because of their capacity to quench a number of free radicals in both aqueous and lipid environments, their metal-chelating properties and ability to restore other antioxidants from their inactive form. The Pheriod™ system is a new manner of drug delivery aimed at overcoming the barrier function of the skin. It consists of vesicular structures, the sizes of which vary from 200-440 nm. These vesicles, prepared from customised essential fatty acids, were found to advance the efficacy of topically administered compounds. The aim of this study was to determine whether the Pheroid™ delivery system would enhance the transdermal delivery of formulations containing alpha-lipoic acid to the target site by performing Franz cell diffusion studies over a 12 hour period, followed by tape-stripping experiments. The results of the formulations containing Pheroid™ were compared to those of the formulations without Pheroid™. Experimental determination of transdermal flux of the alpha-lipoic acid formulations revealed that Pheroid™ improved the transdermal delivery of alpha-lipoic acid. The average flux of Pheroid™ cream from 0 to 2 hours wass 58.01 ± 6.63 ug/cm2.h. The average flux of Pheroid™ gel from 4 to 12 hours was 22.18 ± 3.33 ug/cm2.h. Tape-stripping experiments proved that the concentrations of alpha-lipoic acid in Pheroid™ cream and cream that remained in the epidermis after application to the skin were 569.10 ug/ml and 764.93 ug/ml respectively. The concentrations of alpha-lipoic acid in Pheroid gel and gel that diffused into the dermis were 23.62 ug/ml and 61.06 ug/ml respectively. Aqueous solubility and log D partition coefficient of alpha-lipoic acid were determined. Inspection of the log D value of -0.78 indicated that the compound was unfavourable to penetrate the skin, whereas the aqueous solubility of 8.602 mg/ml in PBS at a temperature of 32 °C indicated favourable penetration. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2010.

Acne is a common skin disease that affects the follicular unit of the skin. Inflammatory- and noninflammatory forms of acne exist. The most affected areas on the body include the face, upper part of the chest and the back. These are the areas with the most sebaceous follicles. Acne occurs when hyperkeratinisation causes the cells of the hair follicle to shed too fast. These cells then block the follicle opening. Thus, sebum cannot pass through the hair follicle onto the skin. The human skin is composed of three layers, namely the epidermis, which acts as a waterproof layer and a barrier to infections; the dermis, which contains the skin appendages; and the subcutaneous fat layer. Skin acts as a protective layer against pathogens and damage to the body. It also provides a semi-impermeable barrier to prevent water loss. Azelaic acid and niacinamide are both currently used in the treatment of acne. Azelaic acid is a saturated dicarboxylic acid which is used to treat mild to moderate acne. It has antibacterial, keratolytic and comedolytic properties. Niacinamide, on the other hand, is the amide of nicotinic acid and is beneficial in the treatment of both papular and pustular acne. It has a demonstrated anti-inflammatory action and causes dose-dependent inhibition of sebocyte secretions. The Pheroid™ delivery system is a colloidal system that consists of even lipid-based submicron-and micron-sized structures that are very unique in nature. This technology is able to improve the absorption and/or efficacy of various active ingredients, as well as other compounds. In this study, a cream, Pheroid™ cream, a gel and a Pheroid™ gel were formulated, containing both azelaic acid and niacinamide. Stability tests were conducted on these formulations for six months, and it was established that none of the formulations were stable under the different storage conditions. Tests that were conducted during stability testing, as determined by the Medicines Control Council, included: assay, mass variation, appearance, viscosity, pH determination and confocal laser scanning microscopy (CLSM). Diffusion studies (12 hours long in total) with vertical Franz cells were conducted with Caucasian female skin obtained after abdominoplastic surgery. Tape-stripping followed in order to establish the epidermis and dermis concentrations of azelaic acid and niacinamide. Significant concentrations of both active ingredients were found in the epidermis and the dermis after 12 hours. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2010.

Local anaesthetics have been implemented extensively in the case of a variety of painful superficial procedures, venipuncture, skin graft harvesting, anal or genital pruritus, poison ivy rashes, postherpetic neuralgia and several other dermatoses. The dilemma with commercially available local acting anaesthetics is that it may take well up to an hour to produce an anaesthetic effect. Anaesthetics have to traverse the highly efficient barrier, the stratum corneum, in order to reach the intended target site which is the free nerve endings located in the dermis. The objective of this study was to compare the transdermal delivery of an eutectic combination of two ionisable amide types of local anaesthetics, lidocaine HCI and prilocaine HCI, delivered with the novel Pheroid™ technology to that of a commercially available product in order to establish whether the lag time could be significantly reduced. Several techniques of promoting the penetration of these anaesthetics have previously been employed, including occlusive dressing, entrapment in liposomes and miscelles, iontophoretic delivery and so forth. The Pheroid™ delivery system is novel technology that entails improved delivery of several active compounds. It is a submicron emulsion type formulation that possesses the ability to be transformed in morphology and size, thereby affording it tremendous flexibility. Since it primarily consists of unsaturated essential fatty acids, it is not seen as foreign to the body but rather as a skin-friendly carrier. Vertical Franz cell diffusion studies were performed over a 12 hour period using Caucasian female abdominal skin obtained, with the consent of the donor, from abdominoplastic surgery. Comparison was made between the commercial product EMLA® cream, the active local anaesthetics dissolved in phosphate buffered solution (PBS) and the active ingredients entrapped within Pheroid™ vesicles. Distinct entrapment could be ascertained visually by confocal laser scanning microscopy (CLSM). The amount of drug that traversed the epidermal membrane into the receptor phase was then assayed by high performance liquid chromatography (HPLC). The results obtained with the Pheroid™ vesicles revealed a biphasic character with rapid permeation during the first two hours, followed by a plateau between 3 to 12 hours. The initial dramatic increase in percentage yield and flux indicates that the Pheroid™ carrier enhances the transdermal delivery of the actives in order to accelerate the onset of action. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2009.

Poor medical adherence attributed to patient compliance has impacted the medical community, at times, in a deleterious fashion. To combat this, the medical community has attempted to provide therapeutics in the form of absorption enhancing techniques. To improve the absorption rate techniques such as drug encapsulation using proteins, liposomes, or nanotransfersomes have been developed using mass spectrometry. These techniques, have aided in the enhanced absorption of analytes with low bioavailability, including curcumin, simvastatin, and lysozyme. Specifically, mass spectrometry allows for the development and monitoring of nanotransfersome encapsulated analytes and the permeation across the dermal membrane. This transdermal delivery would eliminate the problems encountered during first pass metabolism, while allowing for higher concentrations of analyte to be maintained in the blood serum. This can be coupled to a thermosensitive gelatin that provides for a dose control mechanism to be accomplished, allowing multiple doses to be delivered using one transdermal patch system. The novel delivery system developed using mass spectrometry, allows the analyte to be delivered into the circulatory system at a controlled dosage, via transdermal absorption. This system will aid in eliminating problems associated with patient compliance, as the patient is no longer reliant on memory to self-dose. Further, this system mitigates the concerns of patients overdosing with more potent pharmaceuticals.

Diss. (sammanfattning) Uppsala : Univ., 2003. / Härtill 6 uppsatser.

Thesis (Ph.D.)--Bioengineering program, Georgia Institute of Technology, 2008. / Committee Chair: Dr. Mark R. Prausnitz; Committee Co-Chair: Dr. Mark Feinberg; Committee Member: Dr. Mark Allen; Committee Member: Dr. Niren Murthy; Committee Member: Dr. Peter Hesketh; Committee Member: Dr. Robert Swerlick

Thesis (Ph.D)--Chemical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Allen, Mark; Committee Member: Allen, Sue; Committee Member: Glezer, Ari; Committee Member: Koros, Williams; Committee Member: Prausnitz, Mark. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (M.Sc.)--Memorial University of Newfoundland, 1999. / Restricted until November 2000. Bibliography: leaves 114-123.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2003. / Bibliography: leaves 107-127.

Thesis (M. Sc. (Pharmacy))--Rhodes University, 2006.