Implantable drug delivery systems (IDDSs) play a vital role in treating chronic diseases by reducing dosing frequency and enhancing drug efficacy due to targeted delivery. In the present study, an IDDS was developed from electrospun cellulose acetate (CA) and polycaprolactone (PCL) nanofiber membranes. The implant core consists of a drug‐loaded CA nanofiber (CA + Vit.D3) enclosed in a rate limiting of the PCL membrane (CA + Vit.D3/PCL). The CA and PCL nanofibrous membranes were characterized using a scanning electron microscope (SEM), Fourier transform infrared spectroscopy, X‐ray diffraction, and UV–Vis spectroscopy. This research also investigated in‐vitro cytotoxicity and whether the PCL membrane prolonged drug delivery or led to enhanced mechanical properties. A smooth, beadless surface morphology was observed with fiber diameters of 325 ± 101 nm and 333 ± 79 nm for CA and PCL, respectively. In‐vitro drug release and tensile testing showed that surrounding the core's implants with a PCL membrane improved mechanical properties and kinetic drug release. The modulus and tensile strength of CA + Vit.D3/PCL were 161 ± 14 and 13.07 ± 2.5 MPa, respectively—these values were significantly higher than those obtained for CA + Vit.D3 (132 ± 52 MPa and 8.16 ± 2.36 MPa, respectively). The drug release pattern exhibited by CA + Vit.D3 was burst release, which fits the first‐order kinetic model. In contrast, CA + Vit.D3/PCL exhibited slow drug release, which fits the zero‐order kinetic model. In conclusion, based on the outcomes and facility of the technologies outlined in this article, electrospun CA and PCL nanofibers are suitable for developing long‐term IDDSs.