Tricalcium phosphate amino acid capsules as a drug delivery system for steroid hormones

Several researchers have reported that there are drawbacks in using the current pharmacotherapeutic procedure for the treatment of endocrine insufficiency. Furthermore, such drugs have to be taken on a lifelong basis. Also, long term exposure to drugs seems to be necessary in the treatment of the most common endocrine disorders. Thus, the traditional routes of administration expose the body constantly to large fluctuating levels of drugs. This study presents a possible alternative route of administering the drugs for the treatment of the aforementioned cases. Ceramics, such as, tricalcium phosphate (TCP) have been used extensively in the dental and orthopedic fields. To date, the use of compressed TCP ceramic capsules as drug delivery systems has not been investigated. The objective of this study is to investigate the capability of calcined TCP amino acid-steroid matrix to deliver progesterone (P), in a sustained manner. Microcrystals of TCP were prepared by following standard laboratory procedures. Three different amino acids (cysteine, proline, and lysine) were incorporated (individually or in combination form) into the TCP matrix. Each matrix contained 100 mg of P and the homogeneous material was compressed at 5000 Kg compression load using a French Pressure Cell. The total amount of steroid released was monitored spectrophotometrically. The results of this study suggest that: (i) TCP- amino acid-steroid composites can be used to deliver steroids in a sustained manner. (ii) The amount of steroid released from the matrix system was found to be dependent upon the physiochemical characteristics of the amino acids.(ABSTRACT TRUNCATED AT 250 WORDS)