ABSTRACT
Bi-layer tablets have been developed to achieve controlled delivery of different drugs with pre-defined release profiles. In the last decade, interest in developing a combination of two or more Active Pharmaceutical Ingredients (API) in a single dosage form (bilayer tablet) has increased in the pharmaceutical industry, promoting patient convenience and compliance. Bi-layer tablet is suitable for sequential release of two drugs in combination, separate two incompatible substances and also for sustained release tablet in which one Layer is immediate release as initial dose and second layer is maintenance dose. Bilayer tablet is improved beneficial technology to overcome the shortcoming of the single layered tablet. Several pharmaceutical companies are currently developing bi-layer tablets. For a variety of reasons: patent extension, therapeutic, marketing to name a few. To reduce capital investment, quite often existing but modified tablet presses are used to develop and produce such tablets.
KEY WORDS: Bi-layer Tablets, Controlled delivery, Improved bioavailability, Uniform drug delivery.

ABSTRACT

Minocycline is a semi synthetic second generation tetracycline. Apart from antimicrobial activity, it also plays a neuroprotective role in many animal models of acute CNS injuries and neurodegenerative diseases. However, the molecular basis for neuroprotective effects of minocycline remains unclear. In this study, we have evaluated the antioxidant properties of minocycline using the in vitro DPPH assay. This drug was found to have significant antioxidant capacity which could also be a cause for its neuroprotective role and hence can be used in a wide range of conditions.

KEY WORDS: Minocycline, DPPH, Neuroprotective, Antioxidant activity.

ABSTRACT
The transdermal route vied with oral treatment as the most successful innovative research area in drug delivery. The use of lipid vesicles in delivery systems for skin treatment has attracted increasing attention in recent year. Vesicles allow to control the release rate of drug over an extended time, keeping the drug shielded from immune response and would be able to release just the right amount of drug and keeping the concentration constant for longer period of time. Ethosomes are noninvasive delivery carriers that enable drugs to reach the deep skin layer and/or the systemic circulation. These are soft, malleable vesicles tailored for enhanced delivery of active agents. Ethosomes are the ethanolic phospholipid vesicles which are used mainly for transdermal delivery of drugs. Ethosomes have higher penetration rate through the skin as compared to liposomes, hence these can be used widely in place of liposomes. The increased permeation of ethosomes is probably due to its ethanolic content. Ethanol increases the cell membrane lipid fluidity which results in increased skin penetrability of the ethosomes. Evaluation parameter include size, shape, drug content, zeta potential, stability studies, skin permeation studies etc. Ethosome provides a number of important benefits including improving the drug‟s efficiency, enhancing patient compliance and comfort and reducing the total cost of treatment.
KEY WORDS: Transdermal delivery, Liposomes, Ethosome.

ABSTRACT

The main aim of pharmacotherapeutic is the attainment of therapeutic drug concentration at the intended site of action for sufficient period of time to elicit the pharmacological action. A major problem faced by conventional formulation in various routes of administration viz. nasal, ocular, vaginal, rectal, etc is drainage of instilled formulation, poor patient compliance as in the case of vaginal and rectal delivery system. Also, blurred vision and irritation to mucosa is observed in the case of ocular and nasal delivery respectively. The drainage of the formulation results in inaccurate dose delivery thus decreasing the bioavailability of the drug which demands an increase in the frequency of the administration. To overcome these limitations, there is need of novel delivery system such as thermoreversible mucoadhesive insitu gel which provides an ease of administration and improved patient compliance as these smart delivery system is free flowing liquid at ambient temperature and gels at physiological temperature which is higher than the LCST (low critical solution temperature) of thermoreversible polymer. Further this novel formulation can be made more beneficial by inclusion of mucoadhesive polymer which facilitates the adhesion of the formulation and permeation of the drug through the mucous membrane, thereby increasing the residence time and hence the bioavailability of the drug. The insitu gel forming polymeric formulation offers sustained as well as controlled drug delivery which is the prerequisite of the modern pharmaceutical design. The article presents the detailed review of thermoreversible as well as mucoadhesive polymers, mechanism of gelation and mucoadhesion and the factors affecting the same, evaluation methods of thermoreversible mucoadhesive insitu gel and finally various thermoreversible mucoadhesive insitu gel delivery systems (injectable, intramuscular, nasal, ocular, vaginal, rectal, intraoral, periodontal).

KEY WORDS: Insitu gel, Thermoreversible polymers, Mucoadhesive polymers, Low critical solution temperature, Transition temperature, Poloxamer.

ABSTRACT

The present article depicts an elaborative study of proniosomes as specialized drug delivery system. Proniosomes are dry formulation of water-soluble carrier particles that are coated with surfactant and can be measured out as needed and dehydrated to form niosomal dispersion immediately before use on brief agitation in hot aqueous media within minutes. Provesicular systems, such as proniosomes which is one of the advancement in nanotechnology minimize problems of vesicular systems such as aggregation, fusion and leakage of drug and provide additional convenience in transportation, distribution, storage and dosing. Conventional vesicular systems such as liposomes and niosomes are particulate in nature and face stability related difficulty. The review article provides an insight about these approaches along with a novel vesicular approach known as proniosomes. This new emerging concept has demonstrated the potential in improving the oral bioavailability, targeting drugs to the specific site and also permeation of drugs across the stratum corneum. It prolongs the existence of the drug in systemic circulation and finally reduces the toxicity. The goal of this study is to introduce and explore proniosomes as a carrier system for various pharmaceutical and cosmeceutical applications.  

KEY WORDS: Niosomes, Proniosomes, Surfactant, Stability, Colloidal particulate carriers.

ABSTRACT

Transdermal drug delivery has achieved a great importance in the formulation of drug delivery systems which are highly lipophilic in nature as the skin can allow the lipophilic drugs even though having a dead tissue called stratum corneum which is rate limiting step in the drug release but it can be overcome by the usage of penetration enhancers in the formulation. Drugs having short half-life are best suited for transdermal drug delivery system. In this review it has clearly mentioned about the different methods by which TDDS can be formulated.

KEY WORDS: stratum corneum, skin, permeation.