EVALUATION AND CHARACTERIZATION OF TRANSDERMAL THERAPEUTIC SYSTEMS: AN EXHAUSTIVE PICTORIAL AND FIGURATIVE REVIEW

Designing and development of transdermal patches can be described as state of the art. The development of Transdermal drug delivery system is multidisciplinary activity that encompasses fundamental feasibility studies starting from the selection of drug molecule to the demonstration of sufficient drug flux in an ex vivo and in vivo model followed by fabrication of a drug delivery system that meets all the stringent needs that are specific to the drug molecule (physicochemical and stability factors), the patient (comfort and cosmetic appeal), the manufacturer (scale up and manufacturability) and most important the economy. The assessment of the performance of transdermal therapeutic devices designed for controlled drug release may result in a complex analytical issue and multidisciplinary studies focused on the evaluation of physicochemical, morphological and textural properties of the products may be required. This paper presents a review of transdermally applied formulations with emphasis on the evaluation of patches in a wide variety of evaluation parameters such as Physico-chemical evaluation, Adhesive evaluation, Skin irritation test, In-vitro, Ex-vivo, In-vivo techniques using animal models and human skin and Accelerated stability studies.Keywords: Transdermal patches, Physico-chemical evaluation, Adhesive evaluation, Skin irritation test, In-vitro, Ex-vivo and In-vivo techniques, Accelerated stability studies.Â

DEVELOPMENT AND VALIDATION OF BIOANALYTICAL RP HPLC METHOD FOR THE ESTIMATION OF METOPROLOL TARTRATE IN RABBIT PLASMA AFTER TRANSDERMAL AND ORAL ADMINISTRATION: APPLICATION IN PHARMACOKINETIC STUDIES

A simple, specific, sensitive and rapid Reverse phase high performance liquid chromatographic (RP-HPLC) method has been developed and validated for the quantification of Metoprolol Tartrate in small volumes of rabbit plasma. The method was further extended for its pharmacokinetic studies in rabbit plasma samples after transdermal and oral administration. Biological sample preparation involving simple extraction with organic solvent, followed by dilution with mobile phase was adopted to eliminate any chromatographic solvent effects. The method was proven to be linear over a plasma concentration range of 20 ng/ml to100 ng/ml with a mean correlation coefficient of 0.99. The limit of detection and the limit of quantification of the newly developed method were determined to be 5.8ng/mL and 16.1ng/mL, respectively. The method was successfully applied to assess pharmacokinetic parameters of Metoprolol Tartrate in rabbit plasma and found out the comparative bioavailability of MT following oral and transdermal dosage forms. The developed method was established as a rapid analytical tool in a pharmacokinetic study as it required short retention time, high precision, sensitivity and small volumes of plasma for analysis. Keywords: Metoprolol Tartrate, RP-HPLC, quantification, Rabbit plasma, Pharmacokinetic study, oral, transdermal. Â

DEVELOPMENT AND PHYSICO-CHEMICAL EVALUATION OF MONOLITHIC MATRIX TYPE TRANSDERMAL FILMS OF AMMONIA METHACRYLATE COPOLYMER-METHOCEL AND METHACRYLIC ACID COPOLYMER-METHOCEL OF A MODEL ANTI-HYPERTENSIVE DRUG

The main challenge of the present study is to effectively design a Monolithic Matrix type of transdermal films with the use of binary blends of polymers (Methacrylic Acid Copolymer: Acrylcoat S100 & Acrylcoat L100-Methocel K15M and Ammonia Methacrylate Copolymer: Eudragit RSPO & Eudragit RLPO-MK15M and use of most appropriate plasticizer: hydrophilic such as Polyethylene glycol 400 & Propylene Glycol or hydrophobic such as Dibutyl phthalate (DBT) & Dibutyl sebacate for that particular combination of polymers so that a good film can be obtained. In this research work, 2 different permeation enhancers of Terpene class such as d- limonene and 1,8 cineole in combination were used. The Physico-chemical properties of patches determined for the suitability and acceptability of the prepared patches. The thickness, weight, tensile strength, % elongation, folding endurance and flatness were determined for the prepared patches. We found good and acceptable Physicochemical parameters of the matrix films regarding properties and performance. Keywords: Transdermal, Monolithic, Matrix films, Physico-chemical propertie

DESIGN AND EVALUATION OF COLON TARGETED DELIVERY OF TEGASEROD MALEATE FOR IRRITABLE BOWEL SYNDROME

The colon is being extensively investigated as a drug delivery site. Colonic drug delivery is a relatively recent approach for the treatment of diseases like ulcerative colitis, Crohn’s disease, and irritable bowel syndrome. To achieve successful colon targeted drug delivery, a drug needs to be protected from degradation, release and /or absorption in upper portion of GI tract and then ensure abrupt or controlled release in proximal colon. The purpose of this research is to develop and evaluate the polysaccharide based compression coated tablets of Tegaserod maleate for the treatment of irritable bowel syndrome. Core tablets of Tegaserod maleate were compression coated with various proportions of Galactosol, xanthan gum and chitosan. This work aimed to prepare compression coated tablets by direct compression method using single polymer and combination of polymers. And to evaluate prepared tablets parameters like hardness, friability, thickness, diameter, weight variation, drug content, swelling index, in vitro drug release. Keywords: Colon, Tegaserod maleate, Galactosol, xanthan gum and chitosanÂ

Formulation and evaluation of deflazacort loaded mucoadhesive microsphere for colon drug delivery system

Irritable bowel disease is very common colon disease. Deflazacort is one of the best drug with clinical activity against Irritable bowel disease. Microsphere system are effectively protect drugs against premature degradation, to localize drug molecules at the target site of action and to control the time and rate of release. Mucoadhesive microspheres enhance the bioavailability of orally given drugs by lengthened contact time of drug with the intestinal mucosa. The main disadvantage of these microspheres is adherence to the substrate by non-specific interaction. To overcome this limitation, microspheres are prepared by emulsification method to treat irritable bowel disease. Chitosan microspheres were prepared by Ionotropic Gelation method. Microspheres were coated with Eudragil S using solvent evaporation method. Keywords: Deflazacort, Mucoadhesive, Microspheres, Irritable bowel diseas

PREFORMULATION SCREENING OF REPAGLINIDE FOR TRANSDERMAL ANTI-DIABETIC THERAPY

The aim of the present work is to study the preformulation parameters for Transdermal drug delivery system. The objective of Preformulation study is to generic information useful to the formulater in developing stable and bioavailable dosage form. The use of Preformulation parameter maximizes the chances in formulation an acceptable, safe, efficacious and stable product and at the same time provide the basis for optimization of the drug product quality. Administration of conventional tablets of repaglinide has been reported to exhibit fluctuations in plasma drug levels, resulting either in manifestation of side effects or reduction in drug concentration at the receptor sites also, the maintenance of a constant plasma concentration of a anti-diabetic drug is important in ensuring the desired therapeutic response, again since the half life of repaglinide is  01 hour hence multiple doses of the drug are needed to maintain a constant plasma concentration for a good therapeutic response, and improve patient compliance, hence the objective of the study was made to develop controlled release Transdermal Drug Delivery System of repaglinide using polymer like Eudragit RS 100, Eudragit RL 100 and HPMC, which will controlled the release of drug, increasing the bioavailability of the drug and thus decreasing the dosing frequency of the drug. The Preformulation studies were carried out in terms of test for identification (physical appearance, melting point, and uv spectrophotometer), solubility profile, determination of partition coefficient and quantitative estimation of drug. All the observation and results showed that the repaglinide could serve as suitable candidate for Transdermal drug delivery system that may improve the bioavailability. Keywords: Transdermal, Repaglinide, Preformulation, Half Life, bioavailabilit

Bilayer Tablet: Novel Technology Use in Extended Release Drug Delivery System

Bilayer tablet is a successful technology of controlled release formulation or extended release formulation to provide successful drug delivery. The name of this development is clear that the tablets have been consisting of two layers, these are immediate release layer (IR) and another is extended release layer (ER). In this era it is very useful in many developing countries as a combination therapy for various disease treatment purposes. Bilayer tablet are needs to separate incompatible active pharmaceutical ingredients (API) by physical separation. In this formulation IR and ER both layers are present and it form extended release layer (ER). This types of formulations helps to maintain plasma level concentration in the body. So, it is a very useful and successful technology in novel drug delivery system. Keywords: Bilayer tablet, extended drug release, Tablet press

Inherent photoluminescence Stokes shift in GaAs

The intrinsic photoluminescence Stokes shift, i.e., the energy difference between optical band gap and emission peak, of 350 μm thick semi-insulating GaAs wafers is found to be 4 meV at room temperature. The result is based on the determination of the optical bulk band gap from the transmission trend via modified Urbach rule whose result is confirmed with the transmission derivative method. The findings reveal the detailed balance of the optically evoked transitions and disclose the intrinsic link between Stokes shift and the Urbach tail slope parameter

An exhaustive overview of floating drug delivery system

The purpose of writing this review is to narrowing down on floating drug delivery systems (FDDS) and to compile the current literature with special focus on the principal mechanism of floatation to ameliorate gastric retention. The current amelioration of FDDS including the physiological and formulation variables affecting gastric retention approaches to design single unit and multiple unit floating systems, and a plethora and formulation aspects are covered in detail. This review also summarizes the in vitro technique and in vivo studies to evaluate the performance and application of floating systems and applications of these systems. These systems are useful to several plights encountered during the amelioration of a pharmaceutical dosage form. Keywords:  FDDS: Floating Drug Delivery System, ND: Narrowing down, PD: Pharmaceutical dosag