Optimization of Diltiazem hydrochloride osmotic formulation using QBD approach

Abstract Diltiazem hydrochloride (DLH) is a calcium channel blocker useful for the treatment of angina pectoris, arrhythmia, and hypertension. DLH having a short half-life needs frequent administration for successful treatment but this poses a problem of poor patient compliance. These requirements are served by elementary osmotic pump tablets (EOP) based controlled-release (CR) systems. Quality by design (QbD) approach assists in screening various factors with subsequent assessment of critical parameters that can have a major impact on the scalability of EOP. Tablets were formulated using wet granulation method followed by osmotic coating. Factorial design based QbD strategy aided in defining the risk assessment of influential variables such as hydrophilic polymers and osmotic coat component on the in-vitro release kinetics of the designed EOP tablets. These formulated EOP systems followed zero-order kinetics, a characteristic feature of EOPs. EOP tablets were formulated applying a systematic QbD statistical approach. The formulated DLH EOP systems with improved concentration-independent behavior helped to address the challenges of IR formulation. Application of QbD strategy in ascertaining the scalability of DLH EOP formulation would help pharmaceutical industries in the translation of EOP based drug delivery systems from R&D to market.

Formulation and Evaluation of Oral Elementary Osmotic Pump Tablets of Sumatriptan Succinate.

Aim: In the present study, Sumatriptan succinate was formulated as oral elementary osmotic pump with a zero-order drug release profile. Methodology: The effect of different formulation variables i.e. different types of osmogens, concentrations of osmogen and concentration of coating solution were studied. The in vitro evaluation was carried out in different release media. Result: Highest percentage of drug release was observed at high concentration of mannitol i.e., 1:3 (drug: mannitol). Osmogen with low osmotic pressure (38 atm) showed 71.01% zero-order drug release for 12 hours when compared to that of the osmogen with high osmotic pressure (356 atm) which showed 67.38% of release by zero order. Conclusion: Elementary osmotic pump tablets of Sumatriptan succinate were able to deliver zero-order release up to 12 hours independent of pH of dissolution media and have overcome the problem of chronotherapeutic effect.