Formulation development and evaluation of colon targeted delayed release methotrexate pellets for the treatment of colonic carcinoma

Colonic carcinoma is one of the most common internal malignancies and is the second leading cause of deaths in United States. Methotrexate (MTX) is a drug of choice in the treatment of colon cancer. The aim of the present research work was to develop and characterize colon targeted pellets of MTX for treatment of colonic carcinoma. The product and process parameters were optimized by screening methods. Pellets were prepared by extrusion spheronization using microcrystalline cellulose (MCC) as spheronizing aid and ethyl cellulose (EC) as release retardant in different ratio. Based on the physical appearance, sphericity and % in vitro drug release, batch P17 containing EC: MCC (3:7) was optimized for core pellets. The site specificity was obtained by screening the coating polymers and by coating the core pellets with EudragitS100. The 32 full factorial design was applied in which airflow rate (X1) and coating time (X2) were the independent parameters and physical appearance (Y1) and time taken for 100% drug release (Y2) were selected as the dependent variables. From the results obtained, 6min of coating time and 60cm3/min airflow rate was optimized. The batch B5 showed appropriate physical appearance and % in vitro drug release upto 17hr indicating sustained release property. The ex-vivo studies performed on rat colon indicated a significant relation with the in vitro drug release. The drug release followed Higuchi's model indicating the diffusion pattern of drug release from the matrix of pellets. Thus, the coated pellets can be a good candidate for site specific delivery of MTX to colon by decreasing the gastric irritation and thus to improve bioavailability.

Formulation development and evaluation of medicated chewing gum of anti-emetic drug.

CONTEXT: Medicated chewing gum (MCG) of Domperidone Maleate (DM) was developed by direct compression method with the goal to achieve quick onset of action and to improve patient compliance. OBJECTIVE: Formulation development of MCG of DM and optimization of the formulation by screening of different excipients. MATERIAL AND METHODS: MCG containing DM was prepared by screening different concentrations of sweeteners, flavouring agents, softening agents, lubricants and anti-adherents by changing one variable at a time. Performance evaluation was carried out by evaluating size, shape, thickness, taste, scanning electron microscopy, texture analysis, in vivo drug release study, ex vivo buccal permeation study and by studying statistical analysis for quality. RESULTS AND DISCUSSION: The statistical analysis showed significant improvement in organoleptic properties such as chewable mass, product taste, product consistency, product softness, total flavour lasting time and pharmaceutical properties like micromeritic properties after incorporation of appropriate excipients in an optimum amount in final optimized MCG formulation. In vivo drug release study showed 97% DM release whereas ex vivo buccal permeation study through goat buccal mucosa exhibited 11.27% DM permeation within 15 min indicating its potential for increasing bioavailability by decreasing time of onset. The optimized formulation showed good surface properties and the peak load required for drug release was found to be acceptable for crumbling action. CONCLUSION: The developed formulation of medicated chewing gum can be a better alternative to mouth dissolving and conventional tablet formulation. It may be proved as a promising approach to improve the bioavailability as well as to improve patient compliance.

Formulation and evaluation of clotrimazole transdermal spray.

CONTEXT: Transdermal spray (TS) of clotrimazole (CTZ) was formulated to improve the drug transport through the skin up to 12 h to achieve the antifungal efficacy. OBJECTIVE: The aim of present study was to formulate and evaluate antifungal transdermal spray to improve the permeation of clotrimazole across the skin and to decrease the dosing frequency in fungal infection. MATERIALS AND METHODS: Different ratios of ethanol and acetone and various grades of eudragit and ethyl cellulose were evaluated according to six criteria: viscosity, drying time, stickiness, appearance and integrity on skin and water washability. Propylene glycol (PG) and polyethylene glycol 400 (PEG 400) were used in the study as plasticizer and solubilizer. The TS was evaluated for in vitro drug release, spray angle, spray pattern, average weight per dose, pH, drug content, evaporation time, leak test and antifungal efficacy study. RESULTS AND DISCUSSION: Eudragit E100 and blend of ethanol and acetone (80:20) satisfied the desired criteria. The selection of optimized batch was based on the results of in vitro drug release, spray pattern and spray angle. The optimized batch showed the spray angle <85° and uniform spray pattern. The formulation containing PG showed higher drug release than PEG 400. The inclusion of eutectic mixture consisting of camphor and menthol (1:1) showed improved drug transport through the rat skin and larger mean zone of inhibition indicating the improved antifungal efficacy. CONCLUSION: The TS of CTZ can be an innovative and promising approach for the topical administration in the fungal diseases.