Pharmaceutical and medical aspects of hyaluronic acid-ketorolac combination therapy in osteoarthritis treatment: radiographic imaging and bone mineral density.

The objective of this study was to formulate novel painless combined hyaluronic acid (HA)-ketorolac (KT) membrane for the management of osteoarthritis with rapid analgesic onset, thus avoiding HA frequent invasive intra-articular injections and KT gastrointestinal complaints associated with all non-steroidal anti-inflammatory drugs. HA was chemically crosslinked with carbodiimide/glutaraldehyde to yield membrane of low water content. Different in vitro aspects (mechanical properties, water content and in vitro release) were studied leading to an optimized soft, flexible K8 HA membrane containing 30 mg KT that achieved the desired balance of excellent elasticity and low water content. Moreover, a successful retardation of KT release rate was achieved (82%) after 48 h with favored initial fast drug release in the first hour (32.7%) to attain rapid analgesic effect. The clinical assessments in arthritic rats revealed apparent improvement in joint space narrowing, highest increase in bone mineral density at the proximal tibia and distal femur joints with the absence of osteophytosis only in animal group treated with combined HA-KT membrane. Application of K8 membrane was able to preserve KT plasma concentration above its minimum effective concentration for 48 h therefore, would able to replace six commercial tablets each of 10 mg KT.