Surepalli Ram Mohan Rao

Advances in Granulation Technology

Granulation is used in the production of pharmaceutical oral dosage forms. It improves flow and compression characteristics, reduces segregation, improves content uniformity and eliminates excessive amounts of fine particles. The results can be improved yields, reduced tablet defects, increased productivity and reduced down time. Pharmaceutical products are processed all over the world using various granulation methods. The method depends on the ingredients individual characteristics and ability to properly flow, compresses, eject and disintegrate. Selection of method requires thorough investigation of each ingredient in the formula, the combination of ingredients and how they work with each other. Then the proper granulation process can be used. The present review article focuses on the novel granulation technology.

Development and Evaluation of Controlled Porosity Osmotic Pump Tablets for Zidovudine and Lamivudine Combination

The present work was aimed to develop and evaluate controlled porosity osmotic pump (CPOP) tablets of zidovudine-lamivudine combination for the treatment of AIDS. The tablets were prepared by wet granulation method incorporating drug, various excipients, controlled release polymer hydroxyl propyl methyl cellulose (HPMCE5M LV) and osmogen (Mannitol) in the core. The CPOP tablets consist of an osmotic core coated with a micro porous membrane made up of cellulose acetate (CA) which is incorporated with sorbitol as porogen. Prior to compression the prepared granules were evaluated for pre compression parameters such as angle of repose, bulk density, tapped density, Carr’s index and Hausner’s ratio. After compression the prepared granules were evaluated for thickness, coat thickness, hardness, weight variation, friability, drug content, diameter, in vitro drug release study and scanning electron microscopy (SEM) study. The release kinetics for different formulations were analyzed using zero order model equation, first order model equation, Higuchi model equation, Korsmeyer Peppas model equation and Hixson-Crowell equation. The optimized formulation of drug release was independent of pH, agitation intensity, but dependent on the osmotic pressure of the release media. FTIR and DSC study revealed that there was no interaction between drug and excipients. Formulations subjected to stability testing (at 40±2oC/75±5% RH) as per ICH guidelines for three months indicated stability with no significant changes in thickness, hardness, weight variation, friability, drug content and dissolution profiles.

Development and Evaluation of Controlled Release Formulation of Zidovudine Based on Microporous Osmotic Tablet Technology Using Fructose as Osmogen

The present work was aimed to develop and evaluate controlled porosity osmotic pump (CPOP) tablets of an anti HIV drug zidovudine to provide a uniform concentration of drug at absorption site. The formulations were prepared by wet granulation method using drug, various excipients, controlled release polymer hydroxylpropylmethyl cellulose(HPMCE5M LV) and osmogen (Fructose).The CPOP tablets consist of an osmotic core coated with a micro porous membrane made up of cellulose acetate(CA) which is incorporated with sorbitol as porogen. Prior to compression the prepared granules were evaluated for pre compression parameters such as angle of repose, bulk density, tapped density, Carr’s index and Hausner’s ratio. After compression the prepared granules were evaluated for thickness, coat thickness, hardness, weight variation, friability, drug content, diameter, in vitro drug release study and scanning electron microscopy (SEM) study. The release kinetics for different formulations were analyzed using zero order model equation, first order model equation, Higuchi model equation, Korsmeyer Peppas model equation and Hixson-Crowell equation. The optimized formulation of drug release was independent of pH, agitation intensity, but dependent on the osmotic pressure of the release media. Based on the in vitro dissolution profile optimized formulation ZF4 exhibited Fickian transport mechanism with a drug release of 97.83% in 16 hrs. FTIR and DSC study revealed that there was no interaction between drug and excipients. Formulations subjected to stability testing (at 40±2oC/75±5% RH) as per ICH guidelines for three months indicated stability with no significant changes in thickness, hardness, weight variation, friability drug content and dissolution profiles.

Evaluation of controlled porosity osmotic pump tablets: A Review

The objective of present review was to determine the various evaluation tests for controlled porosity osmotic pump tablets. Controlled porosity osmotic pump (CPOP) tablet contains drug, osmogens, excipients in core and a coating of semi permeable membrane with water soluble additives. In CPOP water soluble additives dissolve after coming in contact with water, resulting in an in situ formation of micro porous membrane. CPOP tablets were evaluated for compatibility study, precompression parameters and post compression parameters. The present study gives an idea about various evaluation tests for CPOP tablets.