Volume 2

October-December 2010

Review Articles

N B Khavare, Fatima S Dasankoppa, N G Najundaswamy

During the past three decades significant advances have been made in the area of controlled drug delivery. In a typical therapeutic regimen, the drug dose and the dosing interval are optimized to maintain drug concentration within therapeutic window, thus ensuring efficacy while minimizing toxic side effects. Surveys indicated that dosing more than once or twice daily greatly reduces patient compliance. Hence, the primary objective for controlled drug release is to deliver a pharmacologically active agent in a predetermined, predictable and reproducible manner. Numerous technologies have been used to control the systemic delivery of drugs. One of the most interesting systems employs osmotic pressure as a source of energy. Drug delivery from osmotically controlled oral drug delivery systems (OCODDS), to a large extent, is independent of the physiological factors of the gastrointestinal tract and these systems can be utilized for systemic as well as targeted delivery of drugs. The release of drug(s) from osmotic systems is governed by various formulation factors such as solubility and osmotic pressure of the core component(s), size of the delivery orifice, and nature of the ratecontrolling membrane. By optimizing formulation and processing factors, it is possible to develop osmotic systems to deliver drugs of diverse nature at a preprogrammed rate. In the present review, various types of osmotically controlled oral drug delivery systems, osmosis and mechanism of osmotic controlled release, release kinetics, key parameters that influence the design of osmotic controlled drug delivery systems and critical formulation factors are discussed.

Keywords: Osmotically Controlled Oral Drug Delivery Systems, Osmosis, Release Kinetics, Formulation Factors.

Research Articles

Rukayat Oyi , Sadia Mahmud, Anwuli Ofuokwu

Khaya senegalensis gum (Family: Meliacae), is hereby subjected to some formulation variables; in order to elucidate the effects of such on its swelling capacity. A three factorial design experiment was utilized to find the effects of granule wetness (binder volume), drying temperature and compression pressure on the swelling index of sodium bicarbonate tablets formulated with the gum. The results revealed that binder volume and compression pressure do affect swelling index, while drying temperature had no direct effect on swelling index. Maximum swelling of gum is attained with binder volume of 20-30 % aqueous binder and compression pressure of 5-6 metric tonnes (MT) to produce hard tablets that can withstand handling and prompt release of active medicament. However slower release was obtained with 50 % aqueous binder and 6-7 MT compression pressure. This investigation has established the need to carefully design the formulation pathway, in order to achieve the desired release characteristics.

Keywords: Swelling Capacity, Khaya senegalensis, Matrix Formulation, Modified Release.

D C Nwachukwu, C N Okwuosa, P U Achukwu, Nkiru Azubike, G E Eze


The effect of the leaf extracts of Solanum dulcamara on blood sugar level of diabetic rats was investigated using sixty (60) albino wistar rats and twenty (20) albino mice. Diabetes mellitus was induced in experimental animals by the intraperitoneal administration of alloxan monohydrate (8% w/v). Phytochemical tests revealed the presence of alkaloids, flavonoids, resins, glycosides, saponins, & carbohydrates. Results of acute toxicity tests (LD50) indicated an intra-peritoneal LD50 of 154.91mg/kg and an oral LD50 of 2720mg/kg. Results showed that oral administration of 50mg/kg and 100mg/kg of the methanol extract of Solanum dulcamara (MESD) significantly reduced the blood glucose of diabetic rats at when compared with the untreated diabetic control and the 0 hour glucose value (p˂ 0.05; p<0.001). The antihyperglycaemic action started 2 hours post-drug administration and was sustained throughout the duration of the experiment. The aqueous extract of Solanum dulcamara (AESD) at 100mg/kg reduced blood sugar significantly at 1 and 2 hours when compared with the 0 hour value (p˂ 0.05; p<0.001). This reduction however, did not persist as the glycaemic control was lost after 4 hours. 50mg/kg AESD did not produce anti- hyperglycaemic effects on diabetic rats when compared with control and 0 hour value (p>0.05). The methanol and aqueous extracts of Solanum dulcamara possess significant antihyperglycaemic property.

Keywords: Solanum dulcamara, Extract, Alloxan, Anti-hyperglycaemia.

S Mandal, G N Ratan, J S Mulla, J Thimmasetty, A Kaneriya

Gastro retentive sustained release formulation of tizanidine hydrochloride based floating technology was developed and evaluated. The developed formulation is equivalent to commercial marketed product in view of its in vitro release. The developed formulation has an additional advantage like less steps of manufacturing procedure and is therefore economical. All of which made the procedure easily amenable to mass production using conventional tablet machines. Tizanidine hydrochloride floating tablet formulations were prepared with different compositions using different grade of polymers. Finally, one optimized formula for floating tablet was selected and studied in detail. The effect of formulation variables namely different polymers and concentration of polymer were studied. Tizanidine hydrochloride release was inversely proportional to the polymer concentration. Drug release from the developed formulations was dependent on the agitation intensity and hardness of tablet. Tizanidine hydrochloride release from the developed floating formulation follows first order and diffusion is found to be the main mechanism of drug release. The manufacturing procedure was found to be reproducible and formulations were stable after one month of accelerated stability studies.

Keywords: Sustained Release, Gastro Retentive, Floating Tablet, Tizanidine Hydrochloride, Formulation, Evaluation, Physical Parameters, In vitro Release, Stability.


S O Awofisayo, E Willie, E Umoh

The study is aimed at evaluating the physical properties, quality control parameters and the dissolution profiles of commercial samples of artemether-lumefantrine tablets. The physiochemical parameters and assay of six brands of the products were assessed through the evaluation of uniformity of tablet weight, friability, hardness, disintegration and assay of active pharmaceutical ingredient according to established methods. The dissolution rate and disintegration time were determined in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) without enzymes. The dissolution efficiency (DE) of the tablets of the various brands was used to adjudge their likely in vivo bioavailability. All brands complied with official requirements for uniformity of weight, friability and hardness tests. The disintegration test had higher times in SIF relative to SGF. The dissolution profiles in SGF revealed that two samples attained 70% dissolution in less than 50 min while other samples in more than 1 hour. Only the innovator product, brand A, had T70 of 21 min and others not less than 1.5 hour in SIF. UV spectrophotometric assay of artemether content revealed only three samples containing not less than 90% (w/w) of labeled chemical content. The (DE) for the various brands was significantly higher in SIF relative to SGF (p<0.05). None of the brands evaluated in the study demonstrated comparable quality standards in SGF with respect to the investigated parameters. The method is simple and rugged in routine evaluation of the dissolution profiles of the brands of atemether-lumefantrine available in drug stores and could serve as a useful indicator for quality at the production line.

Keywords: Artemether-Lumefantrine, Multi-source, Dissolution Efficiency, Bioavailability.

Short Communications

P M Ronad, V S Maddi, B C Koti, Y V Kurhe, AHMV Swamy, AHMT Swamy, M S Jaji

Newly synthesized benzopyran-2-one derivatives i.e., 7-(4-hydroxy-3-methoxy benzylideneamino)-4-methyl-2H-chromen-2-one (comp-I), 7-(furan-2-methylene amino)-4-methyl-2H-chromen-2-one (comp-II) and 7-(4-flurobenzyl ideneamino)- 4-methyl-2H-chromen-2-one (comp-III) were assessed for their effects on the convulsant activity by pentylenetetrazole (PTZ) induced seizure model. The results clearly indicated a significant prolongation of onset of seizures and reduced the duration of seizures, where only comp-I was found to be effective in preventing the mortality rate in mice. The anti-convulsant activity was further supported by estimation of serum GABA levels in mice. Comp-I was found to be more potent than comp-II, where as comp-III was less effective as compared to comp- II.

Keywords: Anti-convulsant Activity, Benzopyran-2-one Derivatives, Pentylenetetrazole.

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