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In the present study a hydrodynamically balanced system of celiprolol hydrochloride was developed as single unit floating capsule. Various grades of low density polymers were used for formulation of this system. They were prepared by physical blending of celiprolol hydrochloride and the polymer in varying ratios. The formulation was optimized on the basis of in vitro buoyancy and in vitro release in citrate phosphate buffer at pH 3.0. Effect of various release modifiers was studied to ensure the delivery of drug from the hydrodynamically balanced system capsule over a period of 12 h. Capsule prepared with HPMC K4 M and liquid paraffin gave the best in vitro percentage release and was taken as optimized formulation. By fitting the data in zero order, first order and Higuchi model it could be concluded that the release followed zero order release, as the correlation coefficient was higher for zero order release. It could be concluded from R 2 value for Higuchi model and K-Peppas model that drug release followed fickian diffusion mechanism.

Pulsatile systems are gaining a lot of interest as they deliver the drug at the right site of action at the right time and in the right amount, thus providing spatial and temporal delivery and increasing patient compliance. These systems are designed according to the circadian rhythm of the body. The principle rationale for the use of pulsatile release is for the drugs where a constant drug release, i.e., a zero-order release is not desired. The release of the drug as a pulse after a lag time has to be designed in such a way that a complete and rapid drug release follows the lag time. Various systems like capsular systems, osmotic systems, single- and multiple-unit systems based on the use of soluble or erodible polymer coating and use of rupturable membranes have been dealt with in the article. It summarizes the latest technological developments, formulation parameters, and release profiles of these systems. Products available as once-a-daily formulation based on Pulsatile release like Pulsincap®, Ritalin®, and Pulsys® are also covered in the review. These systems are beneficial for the drugs having chronopharmacological behaviour where night time dosing is required and for the drugs having high first-pass effect and having specific site of absorption in GIT. Drugs used in asthmatic patients and patients suffering from rheumatoid arthritis are also discussed along with many other examples.

In the present study, an attempt was made to develop a low-dose controlled-release delivery system for the treatment of periodontal infections. Nylon fibres were taken as core material. The coating solution contained polyvinyl acetate and amoxycillin trihydrate. The fibres were coated five times to maximize drug loading. The coating composition was optimized and fibres were subjected to in vitro release studies. For the study, a continuous-flow-through apparatus for in situ drug release, simulating the in vivo conditions of periodontal pocket, was designed in a manner that the drug released was well above the minimum inhibitory concentration of amoxycillin trihydrate. In situ samples were further subjected to microbiological evaluation against the microorganisms which are implicated in periodontal infections. Optimized fibre was further subjected to permeation rate study using modified Franz diffusion cell. The drug-coated fibres provided sustained effect up to a period of 11 d (264 h) and followed first-order release. The drug release followed Fickian diffusion mechanism. In situ samples revealed that the drug level at different time intervals remained above its minimum inhibitory concentration (1.5 µg/ml) for a period of 11 d. In situ release samples when subjected to microbiological evaluation against microorganisms inhibited the growth of S. aureus, S. mutans and B. cereus . Permeation rate studies through bovine cheek pouch membrane revealed that only a low level of drug permeated through the membrane and it followed zero-order permeation rate. The retentive fibres were shown to provide controlled delivery of amoxycillin trihydrate.

Mental retardation can follow any of the biological, environmental and psychological events that are capable of producing deficits in cognitive functions. Recent advances in molecular genetic techniques have enabled us to understand more about the molecular basis of several genetic syndromes associated with mental retardation. In contrast, where there is no discrete cause, the interplay of genetic and environmental influences remains poorly understood. This article presents a critical review of literature on genetics of mental retardation.

Background Celecoxib, a selective cyclo-oxygenase-2 inhibitor has been recommended orally for the treatment of arthritis and osteoarthritis. Long term oral administration of celecoxib produces serious gastrointestinal side effects. It is a highly lipophilic, poorly soluble drug with oral bioavailability of around 40% (Capsule). Therefore the aim of the present investigation was to assess the skin permeation mechanism and bioavailability of celecoxib by transdermally applied nanoemulsion formulation. Optimized oil-in-water nanoemulsion of celecoxib was prepared by the aqueous phase titration method. Skin permeation mechanism of celecoxib from nanoemulsion was evaluated by FTIR spectral analysis, DSC thermogram, activation energy measurement and histopathological examination. The optimized nanoemulsion was subjected to pharmacokinetic (bioavailability) studies on Wistar male rats. Results FTIR spectra and DSC thermogram of skin treated with nanoemulsion indicated that permeation occurred due to the disruption of lipid bilayers by nanoemulsion. The significant decrease in activation energy (2.373 kcal/mol) for celecoxib permeation across rat skin indicated that the stratum corneum lipid bilayers were significantly disrupted (p < 0.05). Photomicrograph of skin sample showed the disruption of lipid bilayers as distinct voids and empty spaces were visible in the epidermal region. The absorption of celecoxib through transdermally applied nanoemulsion and nanoemulsion gel resulted in 3.30 and 2.97 fold increase in bioavailability as compared to oral capsule formulation. Conclusion Results of skin permeation mechanism and pharmacokinetic studies indicated that the nanoemulsions can be successfully used as potential vehicles for enhancement of skin permeation and bioavailability of poorly soluble drugs.

The aim of the present study was to investigate the potential of a nanoemulsion formulation for transdermal delivery of aceclofenac. Various oil-in-water nanoemulsions were prepared by the spontaneous emulsification method. The nanoemulsion area was identified by constructing pseudoternary phase diagrams. The prepared nanoemulsions were subjected to different thermodynamic stability tests. The nanoemulsion formulations that passed thermodynamic stability tests were characterized for viscosity, droplet size, transmission electron microscopy, and refractive index. Transdermal permeation of aceclofenac through rat abdominal skin was determined by Franz diffusion cell. The in vitro skin permeation profile of optimized formulations was compared with that of aceclofenac conventional gel and nanoemulsion gel. A significant increase in permeability parameters such as steady-state flux (J(ss)), permeability coefficient (K(p)), and enhancement ratio (E(r)) was observed in optimized nanoemulsion formulation F1, which consisted of 2% wt/wt of aceclofenac, 10% wt/wt of Labrafil, 5% wt/wt of Triacetin, 35.33% wt/wt of Tween 80, 17.66% wt/wt of Transcutol P, and 32% wt/wt of distilled water. The anti-inflammatory effects of formulation F1 showed a significant increase (P.05) in percent inhibition value after 24 hours when compared with aceclofenac conventional gel and nanoemulsion gel on carrageenan-induced paw edema in rats. These results suggested that nanoemulsions are potential vehicles for improved transdermal delivery of aceclofenac.

The purpose of writing this review on floating drug delivery systems (FDDS) was to compile the recent literature with special focus on the principal mechanism of floatation to achieve gastric retention. The recent developments of FDDS including the physiological and formulation variables affecting gastric retention, approaches to design single-unit and multiple-unit floating systems, and their classification and formulation aspects are covered in detail. This review also summarizes the in vitro techniques, in vivo studies to evaluate the performance and application of floating systems, and applications of these systems. These systems are useful to several problems encountered during the development of a pharmaceutical dosage form.

Specific targeting of drug to the colon is recognized to have several therapeutic advantages. Drugs that are destroyed by the acidic environment of the stomach or metabolized by pancreatic enzymes are only slightly affected in the colon. Sustained colonic delivery of drugs can be useful in the treatment of nocturnal asthma, angina, and arthritis. Treatment of colonic diseases such as ulcerative colitis, Crohn's disease, and colorectal cancer is more effective with direct delivery of drugs to the colon. This article is aimed at providing insight into the design considerations and evaluation of colonic drug delivery systems. The anatomy and physiology of the lower gastrointestinal tract is discussed; then the biopharmaceutical aspects are considered in relation to drug absorption in the colon. Various approaches to colon-specific drug delivery are discussed.

Turmeric, the source of the polyphenolic active compound curcumin (diferuloylmethane), has been used extensively in traditional medicine since ancient times as a household remedy against various diseases, including hepatic disorders, cough, sinusitis, rheumatism, and biliary disorders. In the past few decades, a number of studies have been done on curcumin showing its potential role in treating inflammatory disorders, cardiovascular disease, cancer, AIDS, and neurological disorders. However, the main drawback associated with curcumin is its poor aqueous solubility and stability in gastrointestinal fluids, which leads to poor bioavailability. Multifarious novel drug-delivery approaches, including microemulsions, nanoemulsions, liposomes, solid lipid nanoparticles, microspheres, solid dispersion, polymeric nanoparticles, and self-microemulsifying drug-delivery systems have been used to enhance the bioavailability and tissue-targeting ability of curcumin. These attempts have revealed promising results for enhanced bioavailability and targeting to disease such as cancer, but more extensive research on tissue-targeting and stability-related issues is needed. Tissue targeting and enhanced bioavailability of curcumin using novel drug-delivery methods with minimum side effects will in the near future bring this promising natural product to the forefront of therapy for the treatment of human diseases such as cancer and cardiovascular ailments. We provide a detailed analysis of prominent research in the field of curcumin drug delivery with special emphasis on bioavailability-enhancement approaches and novel drug-delivery system approaches.