Dissolution and permeation characteristics of artemether tablets formulated with two gums of different surface activity

Purpose: To evaluate the dissolution and permeation characteristics of artemether tablets formulated with cashew and prosopis gums, and compare with tablets prepared with acacia gum.Methods: Artemether tablets containing varying concentrations (1.0 to 4.0 %w/w) of cashew and prosopis gums or 3 %w/w of acacia (control) gum as binders were formulated by wet granulation method. The tablets were evaluated for crushing strength, friability and disintegration time. Dissolution and permeation characteristics of the formulations were studied using USP methods.Results: Tablets formulated with prosopis gum had higher crushing strength, higher friability and higher disintegration time compared to those of cashew gum at corresponding binder concentrations. Tablets formulated with 3 %w/w cashew gum exhibited complete drug release within 1 h, 95 % drug permeation in 188 min (in simulated gastric fluid [SGF]) and 95 % permeation in 224 min (under simulated intestinal fluid [SIF] condition) while those made with 3 %w/w prosopis gum exhibited 70.7 % drug release in 1 h, 95 % permeation in 135 min (in SGF) and 95 % permeation in 170 min (under SIF condition).Conclusion: Cashew gum is effective as a binder over a relatively wide range of concentrations to achieve fast drug release though with minimal permeation enhancement while prosopis gum is characterized by delayed drug release but enhanced permeation of the released drug.Keywords: Cashew gum, Acacia, Prosopis, Artemether, Drug release, Dissolution, Permeatio

Complementary Approaches to Existing Target Based Drug Discovery for Identifying Novel Drug Targets

In the past decade, it was observed that the relationship between the emerging New Molecular Entities and the quantum of R&D investment has not been favorable. There might be numerous reasons but few studies stress the introduction of target based drug discovery approach as one of the factors. Although a number of drugs have been developed with an emphasis on a single protein target, yet identification of valid target is complex. The approach focuses on an in vitro single target, which overlooks the complexity of cell and makes process of validation drug targets uncertain. Thus, it is imperative to search for alternatives rather than looking at success stories of target-based drug discovery. It would be beneficial if the drugs were developed to target multiple components. New approaches like reverse engineering and translational research need to take into account both system and target-based approach. This review evaluates the strengths and limitations of known drug discovery approaches and proposes alternative approaches for increasing efficiency against treatment

Studies on the antimicrobial properties of formulated creams and ointments containing Baphia nitida heartwood extract

Baphia nitida Lodd (camwood) is widely used medicinal plant in Nigeria for treatment of variety of skin infections. The plant is used in unspecified quantities without standardisation. B. nitida extracts were incorporated in some cream and ointment base in order to present the medicinal plant in an elegant and pharmaceutically acceptable dosage form, as one of the major steps in the scientific evaluation and standardisation of the plant product. The formulated products were evaluated for their antimicrobial activities using agar diffusion technique and microbial challenge test. Their performances were compared with those of standard antiseptic creams and ointments. The results of agar diffusion studies on cream and ointment formulations revealed that the topical bases used to disperse the medicaments could significantly affect the antimicrobial effectiveness of the formulation. Formulations prepared with Aqueous cream BP (a more hydrophilic base; 70% aqueous) exhibited greater antimicrobial activity than the formulation with anionic cream base (a less hydrophilic base; 44% aqueous). Antiseptic creams and ointments containing B. nitida extract, which were effective against various test organisms used in this study, were successful formulated in this work. Journal of Pharmacy & Bioresources Vol. 2(2) 2005: 124-13

Physicochemical and powder properties of alpha- and microcrystalline-cellulose derived from maize cobs

Cob alpha-celluloses (CAC) was extracted from maize cobs by defibering, delignification and bleaching; then subjected to acid hydrolysis to obtain Cob- microcrystalline-cellulose (CMCC). Their physicochemical properties were evaluated and compared with those of Avicel®, a commercial variety of microcrystalline cellulose. Identification tests, and tests for possible contaminants were performed on them. Their powder properties were determined to ascertain their suitability and usefulness in tabletting. The results showed that the extraction process was adequate, as pure alpha cellulose was obtained. Also, the CMCC extracted was found to have comparable powder properties with Avicel®; and one can say that it can be used for similar function as Avicel® in pharmaceutical processes. Key Words: Cob alpha-cellulose (CAC); Cob microcrystalline-cellulose (CMCC);Avicel®; Physicochemical powder properties. Journal of Pharmacy and Bioresources Vol.1(1) 2004: 41-4