Stability and bioavailability of diltiazem/polyethylene oxide matrix tablets

Stability of Abuse-deterrent properties of PEO-based Abuse-deterrent formulation

Abuse of opioid drug products is a national health crisis in the US. To deter abuse, a number of drug products with abuse-deterrent (AD) properties have been approved by the US Food and Drug Administration (FDA). For abuse deterrence, it is critical to maintain the AD properties during the product shelf life. However, no information on the stability of AD properties during product shelf life is publicly available. In this study, stability of AD properties of surrogate AD formulation (ADF) of opioid active pharmaceutical ingredients (APIs) were studied. Surrogate extended release (ER) AD tablets were prepared by direct compression using Diltiazem HCl (model drug), polyethylene oxide (PEO WSR 301) polymer and magnesium stearate followed by curing at 70 °C for 30 mins. The stability studies were conducted at 25 °C/60 % RH and 40 °C/75 % RH storage conditions for 12 months (M) and 6 months (M), respectively. In vitro characterization and evaluation of AD properties of tablets were performed. As anticipated, the curing process increased the crushing strength of the tablets. However, the tablets could still be manipulated and compromised leading to an enhancement in the amount of drug extracted in solvents (e.g., water, alcohol), regardless of extraction temperature as well as tablet storage condition and time. Furthermore, the granule particle size as well as viscosity in water of manipulated samples were found to be lower for tablets stored at 25 °C/60 % RH or 40 °C/75 % RH for 12 M or 3 M/6M, respectively. The changes in AD properties eased the syringeability of hydrated samples and ultimately led to the withdrawal of higher amounts of drug into the syringe, thereby, impacting the abuse deterrence potential of the formulation by an IV route. These data demonstrated that the stability of AD properties (i.e., granule particle size, viscosity and syringeability-injectability) of PEO-based tablets was dependent on the storage condition. In conclusion, the design of AD formulation and setting of product quality profile should take into consideration the stability of AD properties during the product shelf life.

Convolution- and Deconvolution-Based Approaches for Prediction of Pharmacokinetic Parameters of Diltiazem Extended-Release Products in Flow-Through Cell Dissolution Tester

The present study evaluated the effect of different configuration setups of the Flow-Through Cell (USP IV) dissolution tester in developing in vitro-in vivo correlation (IVIVC). A Biopharmaceutics Classification System (BCS) Class I Diltiazem (DTZ), formulated in extended-release (ER) gel-matrix system, was employed for this purpose. The study also assessed the validity and predictability of IVIVC employing both deconvolution- and convolution-based approaches. In vitro release was conducted in USP IV as open- or closed-loop setups, while the pharmacokinetic (PK) data were obtained from a previous fasted-state cross-over study conducted on 8 healthy male volunteers, after oral administration of ER matrix tablets against market product (Tildiem Retard® 90 mg). PK parameters (C_max, AUC_0-t and AUC_0-∞) were predicted, and compared with actual data to establish the strength of correlation models. Results showed that DTZ release from ER products was influenced by operating the FTC in different configuration-setups, where ≥ 75% of labeled DTZ was released after 6 h and 12 h using the open- and closed-loop settings, respectively. Correlation between fraction-dissolved versus fraction-absorbed for both ER products displayed linear relation upon employing FTC open-loop setup. Convolution-based approach was more discriminative in predicting DTZ in vivo PK parameters with a minimal prediction error, compared to deconvolution-based approach. A successful trial to predict DTZ PKs from individual in vitro data performed in USP IV dissolution model was established, employing convolution technique. Basic principle of the convolution approach provides a simple and practical method for developing IVIVC, hence could be utilized for other BCS Class I extended-release drug products.

Novel Glyceryl Monostearate- and Polyethylene Glycol 6000-Based Ibuprofen Pellets Prepared by Hot-Melt Extrusion: Evaluation and Stability Assessment

Purpose

To prepare stable sustained-release (SR) pellets, containing high ibuprofen (IBU) loading, by hot-melt extrusion (HME) technique using polyethylene glycol 6000 (PEG 6000) and glyceryl monostearate (GMS).

Methods

HME pellets (60% w/w IBU) were prepared using PEG 6000, GMS, and mixture of both polymers (1:1). Stability studies were performed under stress conditions (40 °C and relative humidity “RH” of 75%) for 6 months and at room temperature for 12 months. Fresh and stored IBU pellets were evaluated by drug content (HPLC), release rate study (USP apparatus IV), DSC, and XRD.

Results

HME succeeded to produce SR-IBU pellets with high drug loading. PEG 6000 gave higher IBU release rate and relatively unstable formula after storage. PEG 6000/GMS mixture gave prolonged IBU release up to 4 h with stable formula for 12 months at room temperature. While, IBU/GMS pellets gave SR profile up to 6 h and a stable formula under both testing conditions. These advantages of IBU/GMS pellets could be an excellent candidate for SR-IBU product. DSC and XRD analysis data (enthalpy and counts) for IBU and polymers gave a mirror image for IBU release profiles of the studied HME pellets, for both fresh and stored samples.

Conclusion

Stable SR-IBU/GMS HME pellets with high IBU loading (60% w/w) were successfully produced, for the first time, without any other excipients.