FORMULATION VARIABLES AND PROCESS VARIABLES IN COLON TARGETED CAPSULE DOSAGE FORM
Lata Panchal and Prakruti Amin*
Recent studies show its ability to target certain drugs and/or peptides to the colonic region for the treatment of several diseases while avoiding systemic absorption and potential side effects, colon drug delivery has become a field of research of growing interest. Anything which is taken orally will start to dissolve very quickly. Capsule is one of them which includes medication enclosed in a shell. When this shell breaks down in the digestive tract and the medication is absorbed into the bloodstream then drug is distributed and metabolized in similar pattern to the tablet. In the stomach, pH ranges between 1 and 2 during fasting but increases after eating. The polymers described as pH dependent in colon specific drug delivery are insoluble at low pH levels but become increasingly soluble as pH rises. Many drugs are unstable at the acidic pH of stomach therefore many of the tablets and capsules carries a special gastro-resistant coating. Various factors that can affect this targeting and drug release are reviewed in this article. Formulation variables and process variables are critical parameters need to be controlled for optimized drug delivery to the colon. Formulation ingredients play a key role in releasing drug in a controlled manner or to the target site. Local or systemic effect and immediate or prolonger drug release can be possible by varying the type and amount of polymers used in the formulation and also by various approaches such as pH-dependent systems, enzyme-activated systems, receptor-based systems, magnetically activated systems and combination approaches such as Phloral™ technology are also responsible for release of the drug to the target site like colon. This review focuses on Formulation variables and process variables in colon targeted capsule dosage form.
Keywords: Formulation variable, Process variable, Colon targeted, Capsule, Enteric coating, Phloral, Encap, Encode.
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